diff --git a/lib/libc/gen/dl_iterate_phdr.3 b/lib/libc/gen/dl_iterate_phdr.3 index 6e952dc13b57..fe4face9eeb7 100644 --- a/lib/libc/gen/dl_iterate_phdr.3 +++ b/lib/libc/gen/dl_iterate_phdr.3 @@ -1,115 +1,118 @@ .\" Copyright (c) 2005 Mark Kettenis .\" Copyright (c) 2012 Konstantin Belousov .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .\" $OpenBSD: dl_iterate_phdr.3,v 1.3 2007/05/31 19:19:48 jmc Exp $ .\" $FreeBSD$ -.Dd October 9, 2014 +.Dd April 5, 2021 .Dt DL_ITERATE_PHDR 3 .Os .Sh NAME .Nm dl_iterate_phdr .Nd iterate over program headers .Sh LIBRARY For the dynamically linked binaries, the service is provided by .Xr ld-elf.so.1 1 dynamic linker. Statically linked programs use an implementation of .Fn dl_iterate_phdr from libc. .Sh SYNOPSIS .In link.h .Ft int .Fn dl_iterate_phdr "int (*callback)(struct dl_phdr_info *, size_t, void *)" "void *data" .Sh DESCRIPTION The .Fn dl_iterate_phdr function iterates over all ELF objects loaded into a process's address space, calling .Fa callback for each object, passing it information about the object's program headers and the .Fa data argument. The iteration is aborted when all objects are passed, or when the next .Fa callback call returns non-zero value. The information about the program headers is passed in a structure that is defined as: .Bd -literal struct dl_phdr_info { Elf_Addr dlpi_addr; const char *dlpi_name; const Elf_Phdr *dlpi_phdr; Elf_Half dlpi_phnum; unsigned long long int dlpi_adds; unsigned long long int dlpi_subs; size_t dlpi_tls_modid; void *dlpi_tls_data; }; .Ed .Pp The members of .Li struct dl_phdr_info have the following meaning: .Bl -tag -width dlpi_tls_modid .It Fa dlpi_addr The base address at which the object is mapped into the address space of the calling process. .It Fa dlpi_name The pathname of the ELF object. .It Fa dlpi_phdr A pointer to the object's program headers. .It Fa dlpi_phnum The number of program headers in the object. .It Fa dlpi_adds The counter of the object loads performed by the dynamic linker. .It Fa dlpi_subs The counter of the object unloads performed by the dynamic linker. .It Fa dlpi_tls_modid The TLS index of the object. .It Fa dlpi_tls_data -A pointer to the initialization data for the object TLS segment. +A pointer to the calling thread' TLS data segment for this module, +if it was allocated, +.Dv NULL +otherwise. .El .Pp Future versions of .Fx might add more members to this structure. To make it possible for programs to check whether any new members have been added, the size of the structure is passed as an second argument to .Fa callback . .Pp The third argument to callback is the .Fa data value passed to the call to .Fn dl_iterate_phdr , allowing the .Fa callback to have a context. .Sh RETURN VALUES The .Fn dl_iterate_phdr returns the value returned by the last .Fa callback call executed. .Sh SEE ALSO .Xr ld 1 , .Xr ld-elf.so.1 1 , .Xr dlopen 3 , .Xr elf 5 .Sh HISTORY The .Nm function first appeared in .Fx 7.0 . diff --git a/libexec/rtld-elf/Symbol.map b/libexec/rtld-elf/Symbol.map index 13068c5626dc..0a9eac82cf05 100644 --- a/libexec/rtld-elf/Symbol.map +++ b/libexec/rtld-elf/Symbol.map @@ -1,37 +1,38 @@ /* * $FreeBSD$ */ FBSD_1.0 { _rtld_error; dlclose; dlerror; dlopen; dlsym; dlfunc; dlvsym; dladdr; dllockinit; dlinfo; dl_iterate_phdr; r_debug_state; __tls_get_addr; }; FBSD_1.3 { fdlopen; }; FBSDprivate_1.0 { _rtld_thread_init; _rtld_allocate_tls; _rtld_free_tls; _rtld_atfork_pre; _rtld_atfork_post; _rtld_addr_phdr; _rtld_get_stack_prot; _rtld_is_dlopened; _r_debug_postinit; _rtld_version__FreeBSD_version; _rtld_version_laddr_offset; + _rtld_version_dlpi_tls_data; }; diff --git a/libexec/rtld-elf/rtld.1 b/libexec/rtld-elf/rtld.1 index 589b9a92aa77..7f633ce0b486 100644 --- a/libexec/rtld-elf/rtld.1 +++ b/libexec/rtld-elf/rtld.1 @@ -1,446 +1,453 @@ .\" Copyright (c) 1995 Paul Kranenburg .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgment: .\" This product includes software developed by Paul Kranenburg. .\" 3. The name of the author may not be used to endorse or promote products .\" derived from this software without specific prior written permission .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" .\" $FreeBSD$ .\" .Dd March 24, 2021 .Dt RTLD 1 .Os .Sh NAME .Nm ld-elf.so.1 , .Nm ld.so , .Nm rtld .Nd run-time link-editor .Sh DESCRIPTION The .Nm utility is a self-contained shared object providing run-time support for loading and link-editing shared objects into a process' address space. It is also commonly known as the dynamic linker. It uses the data structures contained within dynamically linked programs to determine which shared libraries are needed and loads them using the .Xr mmap 2 system call. .Pp After all shared libraries have been successfully loaded, .Nm proceeds to resolve external references from both the main program and all objects loaded. A mechanism is provided for initialization routines to be called on a per-object basis, giving a shared object an opportunity to perform any extra set-up before execution of the program proper begins. This is useful for C++ libraries that contain static constructors. .Pp When resolving dependencies for the loaded objects, .Nm translates dynamic token strings in rpath and soname. If the .Fl "z origin" option of the static linker was set when linking the binary, the token expansion is performed at the object load time, see .Xr ld 1 . The following strings are recognized now: .Bl -tag -width ".Pa $PLATFORM" .It Pa $ORIGIN Translated to the full path of the loaded object. .It Pa $OSNAME Translated to the name of the operating system implementation. .It Pa $OSREL Translated to the release level of the operating system. .It Pa $PLATFORM Translated to the machine hardware platform. .El .Pp The .Nm utility itself is loaded by the kernel together with any dynamically-linked program that is to be executed. The kernel transfers control to the dynamic linker. After the dynamic linker has finished loading, relocating, and initializing the program and its required shared objects, it transfers control to the entry point of the program. The following search order is used to locate required shared objects: .Pp .Bl -enum -offset indent -compact .It .Dv DT_RPATH of the referencing object unless that object also contains a .Dv DT_RUNPATH tag .It .Dv DT_RPATH of the program unless the referencing object contains a .Dv DT_RUNPATH tag .It Path indicated by .Ev LD_LIBRARY_PATH environment variable .It .Dv DT_RUNPATH of the referencing object .It Hints file produced by the .Xr ldconfig 8 utility .It The .Pa /lib and .Pa /usr/lib directories, unless the referencing object was linked using the .Dq Fl z Ar nodefaultlib option .El .Pp The .Nm utility recognizes a number of environment variables that can be used to modify its behaviour. On 64-bit architectures, the linker for 32-bit objects recognizes all the environment variables listed below, but is being prefixed with .Ev LD_32_ , for example: .Ev LD_32_TRACE_LOADED_OBJECTS . .Bl -tag -width ".Ev LD_LIBMAP_DISABLE" .It Ev LD_DUMP_REL_POST If set, .Nm will print a table containing all relocations after symbol binding and relocation. .It Ev LD_DUMP_REL_PRE If set, .Nm will print a table containing all relocations before symbol binding and relocation. .It Ev LD_LIBMAP A library replacement list in the same format as .Xr libmap.conf 5 . For convenience, the characters .Ql = and .Ql \&, can be used instead of a space and a newline. This variable is parsed after .Xr libmap.conf 5 , and will override its entries. This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_LIBMAP_DISABLE If set, disables the use of .Xr libmap.conf 5 and .Ev LD_LIBMAP . This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_ELF_HINTS_PATH This variable will override the default location of .Dq hints file. This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_LIBRARY_PATH A colon separated list of directories, overriding the default search path for shared libraries. This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_LIBRARY_PATH_RPATH If the variable is specified and has a value starting with any of \'y\', \'Y\' or \'1\' symbols, the path specified by .Ev LD_LIBRARY_PATH variable is allowed to override the path from .Dv DT_RPATH for binaries which does not contain .Dv DT_RUNPATH tag. For such binaries, when the variable .Ev LD_LIBRARY_PATH_RPATH is set, .Dq Fl z Ar nodefaultlib link-time option is ignored as well. .It Ev LD_PRELOAD A list of shared libraries, separated by colons and/or white space, to be linked in before any other shared libraries. If the directory is not specified then the directories specified by .It Ev LD_PRELOAD_FDS A colon separated list of file descriptor numbers for libraries. This is intended for preloading libraries in which we already have a file descriptor. This may optimize the process of loading libraries because we do not have to look for them in directories. It may also be useful in a capability base system where we do not have access to global namespaces such as the filesystem. .Ev LD_LIBRARY_PATH will be searched first followed by the set of built-in standard directories. This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_LIBRARY_PATH_FDS A colon separated list of file descriptor numbers for library directories. This is intended for use within .Xr capsicum 4 sandboxes, when global namespaces such as the filesystem are unavailable. It is consulted just after LD_LIBRARY_PATH. This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_BIND_NOT When set to a nonempty string, prevents modifications of the PLT slots when doing bindings. As result, each call of the PLT-resolved function is resolved. In combination with debug output, this provides complete account of all bind actions at runtime. This variable is unset for set-user-ID and set-group-ID programs. .It Ev LD_BIND_NOW When set to a nonempty string, causes .Nm to relocate all external function calls before starting execution of the program. Normally, function calls are bound lazily, at the first call of each function. .Ev LD_BIND_NOW increases the start-up time of a program, but it avoids run-time surprises caused by unexpectedly undefined functions. .It Ev LD_TRACE_LOADED_OBJECTS When set to a nonempty string, causes .Nm to exit after loading the shared objects and printing a summary which includes the absolute pathnames of all objects, to standard output. .It Ev LD_TRACE_LOADED_OBJECTS_ALL When set to a nonempty string, causes .Nm to expand the summary to indicate which objects caused each object to be loaded. .It Ev LD_TRACE_LOADED_OBJECTS_FMT1 .It Ev LD_TRACE_LOADED_OBJECTS_FMT2 When set, these variables are interpreted as format strings a la .Xr printf 3 to customize the trace output and are used by .Xr ldd 1 Ns 's .Fl f option and allows .Xr ldd 1 to be operated as a filter more conveniently. If the dependency name starts with string .Pa lib , .Ev LD_TRACE_LOADED_OBJECTS_FMT1 is used, otherwise .Ev LD_TRACE_LOADED_OBJECTS_FMT2 is used. The following conversions can be used: .Bl -tag -width 4n .It Li %a The main program's name (also known as .Dq __progname ) . .It Li \&%A The value of the environment variable .Ev LD_TRACE_LOADED_OBJECTS_PROGNAME . Typically used to print both the names of programs and shared libraries being inspected using .Xr ldd 1 . .It Li %o The library name. .It Li %p The full pathname as determined by .Nm rtld Ns 's library search rules. .It Li %x The library's load address. .El .Pp Additionally, .Ql \en and .Ql \et are recognized and have their usual meaning. .It Ev LD_UTRACE If set, .Nm will log events such as the loading and unloading of shared objects via .Xr utrace 2 . .It Ev LD_LOADFLTR If set, .Nm will process the filtee dependencies of the loaded objects immediately, instead of postponing it until required. Normally, the filtees are opened at the time of the first symbol resolution from the filter object. .El .Sh DIRECT EXECUTION MODE .Nm is typically used implicitly, loaded by the kernel as requested by the .Dv PT_INTERP program header of the executed binary. .Fx also supports a direct execution mode for the dynamic linker. In this mode, the user explicitly executes .Nm and provides the path of the program to be linked and executed as an argument. This mode allows use of a non-standard dynamic linker for a program activation without changing the binary or without changing the installed dynamic linker. Execution options may be specified. .Pp The syntax of the direct invocation is .Bd -ragged -offset indent .Pa /libexec/ld-elf.so.1 .Op Fl b Ar exe .Op Fl f Ar fd .Op Fl p .Op Fl - .Pa image_path .Op Ar image arguments .Ed .Pp The options are: .Bl -tag -width indent .It Fl b Ar exe Use the executable .Fa exe instead of .Fa image_path for activation. If this option is specified, .Ar image_path is only used to provide the .Va argv[0] value to the program. .It Fl f Ar fd File descriptor .Ar fd references the binary to be activated by .Nm . It must already be opened in the process when executing .Nm . If this option is specified, .Ar image_path is only used to provide the .Va argv[0] value to the program. .It Fl p If the .Pa image_path argument specifies a name which does not contain a slash .Dq Li / character, .Nm uses the search path provided by the environment variable .Dv PATH to find the binary to execute. .It Fl v Display information about this run-time linker binary, then exit. .It Fl - Ends the .Nm options. The argument following .Fl - is interpreted as the path of the binary to execute. .El .Pp In the direct execution mode, .Nm emulates verification of the binary execute permission for the current user. This is done to avoid breaking user expectations in naively restricted execution environments. The verification only uses Unix .Dv DACs , ignores .Dv ACLs , and is naturally prone to race conditions. Environments which rely on such restrictions are weak and breakable on their own. .Sh VERSIONING Newer .Nm might provide some features or changes in runtime behavior that cannot be easily detected at runtime by checking of the normal exported symbols. Note that it is almost always wrong to verify .Dv __FreeBSD_version in userspace to detect features, either at compile or at run time, because either kernel, or libc, or environment variables could not match the running .Nm . .Pp To solve the problem, .Nm exports some feature indicators in the .Fx private symbols namespace .Dv FBSDprivate_1.0 . Symbols start with the .Dv _rtld_version prefix. Current list of defined symbols and corresponding features is: .Bl -tag -width indent .It Dv _rtld_version__FreeBSD_version Symbol exports the value of the .Dv __FreeBSD_version definition as it was provided during the .Nm build. The symbol is always present since the .Dv _rtld_version facility was introduced. .It Dv _rtld_version_laddr_offset The .Va l_addr member of the .Vt link_map structure contains the load offset of the shared object. Before that, .Va l_addr contained the base address of the library. See .Xr dlinfo 3 . .Pp Also it indicates the presence of .Va l_refname member of the structure. +.It Dv _rtld_version_dlpi_tls_data +The +.Va dlpi_tls_data +member of the structure +.Vt dl_phdr_info +contains the address of the module TLS segment for the calling thread, +and not the address of the initialization segment. .El .Sh FILES .Bl -tag -width ".Pa /var/run/ld-elf32.so.hints" -compact .It Pa /var/run/ld-elf.so.hints Hints file. .It Pa /var/run/ld-elf32.so.hints Hints file for 32-bit binaries on 64-bit system. .It Pa /etc/libmap.conf The libmap configuration file. .It Pa /etc/libmap32.conf The libmap configuration file for 32-bit binaries on 64-bit system. .El .Sh SEE ALSO .Xr ld 1 , .Xr ldd 1 , .Xr dlinfo 3 , .Xr capsicum 4 , .Xr elf 5 , .Xr libmap.conf 5 , .Xr ldconfig 8 diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c index 733c3c80b70f..19027518d3c2 100644 --- a/libexec/rtld-elf/rtld.c +++ b/libexec/rtld-elf/rtld.c @@ -1,5916 +1,5922 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. * Copyright 2003 Alexander Kabaev . * Copyright 2009-2013 Konstantin Belousov . * Copyright 2012 John Marino . * Copyright 2014-2017 The FreeBSD Foundation * All rights reserved. * * Portions of this software were developed by Konstantin Belousov * under sponsorship from the FreeBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Dynamic linker for ELF. * * John Polstra . */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "debug.h" #include "rtld.h" #include "libmap.h" #include "paths.h" #include "rtld_tls.h" #include "rtld_printf.h" #include "rtld_malloc.h" #include "rtld_utrace.h" #include "notes.h" #include "rtld_libc.h" /* Types. */ typedef void (*func_ptr_type)(void); typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); /* Variables that cannot be static: */ extern struct r_debug r_debug; /* For GDB */ extern int _thread_autoinit_dummy_decl; extern void (*__cleanup)(void); /* * Function declarations. */ static const char *basename(const char *); static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, const Elf_Dyn **, const Elf_Dyn **); static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, const Elf_Dyn *); static bool digest_dynamic(Obj_Entry *, int); static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); static void distribute_static_tls(Objlist *, RtldLockState *); static Obj_Entry *dlcheck(void *); static int dlclose_locked(void *, RtldLockState *); static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, int mode, RtldLockState *lockstate); static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); static bool donelist_check(DoneList *, const Obj_Entry *); static void errmsg_restore(char *); static char *errmsg_save(void); static void *fill_search_info(const char *, size_t, void *); static char *find_library(const char *, const Obj_Entry *, int *); static const char *gethints(bool); static void hold_object(Obj_Entry *); static void unhold_object(Obj_Entry *); static void init_dag(Obj_Entry *); static void init_marker(Obj_Entry *); static void init_pagesizes(Elf_Auxinfo **aux_info); static void init_rtld(caddr_t, Elf_Auxinfo **); static void initlist_add_neededs(Needed_Entry *, Objlist *); static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); static void linkmap_add(Obj_Entry *); static void linkmap_delete(Obj_Entry *); static void load_filtees(Obj_Entry *, int flags, RtldLockState *); static void unload_filtees(Obj_Entry *, RtldLockState *); static int load_needed_objects(Obj_Entry *, int); static int load_preload_objects(char *, bool); static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); static void map_stacks_exec(RtldLockState *); static int obj_disable_relro(Obj_Entry *); static int obj_enforce_relro(Obj_Entry *); static Obj_Entry *obj_from_addr(const void *); static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); static void objlist_call_init(Objlist *, RtldLockState *); static void objlist_clear(Objlist *); static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); static void objlist_init(Objlist *); static void objlist_push_head(Objlist *, Obj_Entry *); static void objlist_push_tail(Objlist *, Obj_Entry *); static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); static void objlist_remove(Objlist *, Obj_Entry *); static int open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res); static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, const char **argv0); static int parse_integer(const char *); static void *path_enumerate(const char *, path_enum_proc, const char *, void *); static void print_usage(const char *argv0); static void release_object(Obj_Entry *); static int relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, RtldLockState *); static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); static int rtld_dirname(const char *, char *); static int rtld_dirname_abs(const char *, char *); static void *rtld_dlopen(const char *name, int fd, int mode); static void rtld_exit(void); static void rtld_nop_exit(void); static char *search_library_path(const char *, const char *, const char *, int *); static char *search_library_pathfds(const char *, const char *, int *); static const void **get_program_var_addr(const char *, RtldLockState *); static void set_program_var(const char *, const void *); static int symlook_default(SymLook *, const Obj_Entry *refobj); static int symlook_global(SymLook *, DoneList *); static void symlook_init_from_req(SymLook *, const SymLook *); static int symlook_list(SymLook *, const Objlist *, DoneList *); static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); static void trace_loaded_objects(Obj_Entry *); static void unlink_object(Obj_Entry *); static void unload_object(Obj_Entry *, RtldLockState *lockstate); static void unref_dag(Obj_Entry *); static void ref_dag(Obj_Entry *); static char *origin_subst_one(Obj_Entry *, char *, const char *, const char *, bool); static char *origin_subst(Obj_Entry *, const char *); static bool obj_resolve_origin(Obj_Entry *obj); static void preinit_main(void); static int rtld_verify_versions(const Objlist *); static int rtld_verify_object_versions(Obj_Entry *); static void object_add_name(Obj_Entry *, const char *); static int object_match_name(const Obj_Entry *, const char *); static void ld_utrace_log(int, void *, void *, size_t, int, const char *); static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info); static uint32_t gnu_hash(const char *); static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, const unsigned long); void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; void _r_debug_postinit(struct link_map *) __noinline __exported; int __sys_openat(int, const char *, int, ...); /* * Data declarations. */ static char *error_message; /* Message for dlerror(), or NULL */ struct r_debug r_debug __exported; /* for GDB; */ static bool libmap_disable; /* Disable libmap */ static bool ld_loadfltr; /* Immediate filters processing */ static char *libmap_override; /* Maps to use in addition to libmap.conf */ static bool trust; /* False for setuid and setgid programs */ static bool dangerous_ld_env; /* True if environment variables have been used to affect the libraries loaded */ bool ld_bind_not; /* Disable PLT update */ static char *ld_bind_now; /* Environment variable for immediate binding */ static char *ld_debug; /* Environment variable for debugging */ static char *ld_library_path; /* Environment variable for search path */ static char *ld_library_dirs; /* Environment variable for library descriptors */ static char *ld_preload; /* Environment variable for libraries to load first */ static char *ld_preload_fds; /* Environment variable for libraries represented by descriptors */ static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ static const char *ld_tracing; /* Called from ldd to print libs */ static char *ld_utrace; /* Use utrace() to log events. */ static struct obj_entry_q obj_list; /* Queue of all loaded objects */ static Obj_Entry *obj_main; /* The main program shared object */ static Obj_Entry obj_rtld; /* The dynamic linker shared object */ static unsigned int obj_count; /* Number of objects in obj_list */ static unsigned int obj_loads; /* Number of loads of objects (gen count) */ static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ STAILQ_HEAD_INITIALIZER(list_global); static Objlist list_main = /* Objects loaded at program startup */ STAILQ_HEAD_INITIALIZER(list_main); static Objlist list_fini = /* Objects needing fini() calls */ STAILQ_HEAD_INITIALIZER(list_fini); Elf_Sym sym_zero; /* For resolving undefined weak refs. */ #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); extern Elf_Dyn _DYNAMIC; #pragma weak _DYNAMIC int dlclose(void *) __exported; char *dlerror(void) __exported; void *dlopen(const char *, int) __exported; void *fdlopen(int, int) __exported; void *dlsym(void *, const char *) __exported; dlfunc_t dlfunc(void *, const char *) __exported; void *dlvsym(void *, const char *, const char *) __exported; int dladdr(const void *, Dl_info *) __exported; void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), void (*)(void *), void (*)(void *), void (*)(void *)) __exported; int dlinfo(void *, int , void *) __exported; int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; int _rtld_get_stack_prot(void) __exported; int _rtld_is_dlopened(void *) __exported; void _rtld_error(const char *, ...) __exported; /* Only here to fix -Wmissing-prototypes warnings */ int __getosreldate(void); func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); int npagesizes; static int osreldate; size_t *pagesizes; static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; static int max_stack_flags; /* * Global declarations normally provided by crt1. The dynamic linker is * not built with crt1, so we have to provide them ourselves. */ char *__progname; char **environ; /* * Used to pass argc, argv to init functions. */ int main_argc; char **main_argv; /* * Globals to control TLS allocation. */ size_t tls_last_offset; /* Static TLS offset of last module */ size_t tls_last_size; /* Static TLS size of last module */ size_t tls_static_space; /* Static TLS space allocated */ static size_t tls_static_max_align; Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ int tls_max_index = 1; /* Largest module index allocated */ static bool ld_library_path_rpath = false; bool ld_fast_sigblock = false; /* * Globals for path names, and such */ const char *ld_elf_hints_default = _PATH_ELF_HINTS; const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; const char *ld_path_rtld = _PATH_RTLD; const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; const char *ld_env_prefix = LD_; static void (*rtld_exit_ptr)(void); /* * Fill in a DoneList with an allocation large enough to hold all of * the currently-loaded objects. Keep this as a macro since it calls * alloca and we want that to occur within the scope of the caller. */ #define donelist_init(dlp) \ ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ assert((dlp)->objs != NULL), \ (dlp)->num_alloc = obj_count, \ (dlp)->num_used = 0) #define LD_UTRACE(e, h, mb, ms, r, n) do { \ if (ld_utrace != NULL) \ ld_utrace_log(e, h, mb, ms, r, n); \ } while (0) static void ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, int refcnt, const char *name) { struct utrace_rtld ut; static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); ut.event = event; ut.handle = handle; ut.mapbase = mapbase; ut.mapsize = mapsize; ut.refcnt = refcnt; bzero(ut.name, sizeof(ut.name)); if (name) strlcpy(ut.name, name, sizeof(ut.name)); utrace(&ut, sizeof(ut)); } #ifdef RTLD_VARIANT_ENV_NAMES /* * construct the env variable based on the type of binary that's * running. */ static inline const char * _LD(const char *var) { static char buffer[128]; strlcpy(buffer, ld_env_prefix, sizeof(buffer)); strlcat(buffer, var, sizeof(buffer)); return (buffer); } #else #define _LD(x) LD_ x #endif /* * Main entry point for dynamic linking. The first argument is the * stack pointer. The stack is expected to be laid out as described * in the SVR4 ABI specification, Intel 386 Processor Supplement. * Specifically, the stack pointer points to a word containing * ARGC. Following that in the stack is a null-terminated sequence * of pointers to argument strings. Then comes a null-terminated * sequence of pointers to environment strings. Finally, there is a * sequence of "auxiliary vector" entries. * * The second argument points to a place to store the dynamic linker's * exit procedure pointer and the third to a place to store the main * program's object. * * The return value is the main program's entry point. */ func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) { Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; Objlist_Entry *entry; Obj_Entry *last_interposer, *obj, *preload_tail; const Elf_Phdr *phdr; Objlist initlist; RtldLockState lockstate; struct stat st; Elf_Addr *argcp; char **argv, **env, **envp, *kexecpath, *library_path_rpath; const char *argv0, *binpath; caddr_t imgentry; char buf[MAXPATHLEN]; int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; size_t sz; #ifdef __powerpc__ int old_auxv_format = 1; #endif bool dir_enable, direct_exec, explicit_fd, search_in_path; /* * On entry, the dynamic linker itself has not been relocated yet. * Be very careful not to reference any global data until after * init_rtld has returned. It is OK to reference file-scope statics * and string constants, and to call static and global functions. */ /* Find the auxiliary vector on the stack. */ argcp = sp; argc = *sp++; argv = (char **) sp; sp += argc + 1; /* Skip over arguments and NULL terminator */ env = (char **) sp; while (*sp++ != 0) /* Skip over environment, and NULL terminator */ ; aux = (Elf_Auxinfo *) sp; /* Digest the auxiliary vector. */ for (i = 0; i < AT_COUNT; i++) aux_info[i] = NULL; for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { if (auxp->a_type < AT_COUNT) aux_info[auxp->a_type] = auxp; #ifdef __powerpc__ if (auxp->a_type == 23) /* AT_STACKPROT */ old_auxv_format = 0; #endif } #ifdef __powerpc__ if (old_auxv_format) { /* Remap from old-style auxv numbers. */ aux_info[23] = aux_info[21]; /* AT_STACKPROT */ aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ aux_info[19] = aux_info[17]; /* AT_NCPUS */ aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ aux_info[15] = aux_info[13]; /* AT_EXECPATH */ aux_info[13] = NULL; /* AT_GID */ aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ aux_info[16] = aux_info[14]; /* AT_CANARY */ aux_info[14] = NULL; /* AT_EGID */ } #endif /* Initialize and relocate ourselves. */ assert(aux_info[AT_BASE] != NULL); init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); __progname = obj_rtld.path; argv0 = argv[0] != NULL ? argv[0] : "(null)"; environ = env; main_argc = argc; main_argv = argv; if (aux_info[AT_BSDFLAGS] != NULL && (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) ld_fast_sigblock = true; trust = !issetugid(); direct_exec = false; md_abi_variant_hook(aux_info); fd = -1; if (aux_info[AT_EXECFD] != NULL) { fd = aux_info[AT_EXECFD]->a_un.a_val; } else { assert(aux_info[AT_PHDR] != NULL); phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; if (phdr == obj_rtld.phdr) { if (!trust) { _rtld_error("Tainted process refusing to run binary %s", argv0); rtld_die(); } direct_exec = true; dbg("opening main program in direct exec mode"); if (argc >= 2) { rtld_argc = parse_args(argv, argc, &search_in_path, &fd, &argv0); explicit_fd = (fd != -1); binpath = NULL; if (!explicit_fd) fd = open_binary_fd(argv0, search_in_path, &binpath); if (fstat(fd, &st) == -1) { _rtld_error("Failed to fstat FD %d (%s): %s", fd, explicit_fd ? "user-provided descriptor" : argv0, rtld_strerror(errno)); rtld_die(); } /* * Rough emulation of the permission checks done by * execve(2), only Unix DACs are checked, ACLs are * ignored. Preserve the semantic of disabling owner * to execute if owner x bit is cleared, even if * others x bit is enabled. * mmap(2) does not allow to mmap with PROT_EXEC if * binary' file comes from noexec mount. We cannot * set a text reference on the binary. */ dir_enable = false; if (st.st_uid == geteuid()) { if ((st.st_mode & S_IXUSR) != 0) dir_enable = true; } else if (st.st_gid == getegid()) { if ((st.st_mode & S_IXGRP) != 0) dir_enable = true; } else if ((st.st_mode & S_IXOTH) != 0) { dir_enable = true; } if (!dir_enable) { _rtld_error("No execute permission for binary %s", argv0); rtld_die(); } /* * For direct exec mode, argv[0] is the interpreter * name, we must remove it and shift arguments left * before invoking binary main. Since stack layout * places environment pointers and aux vectors right * after the terminating NULL, we must shift * environment and aux as well. */ main_argc = argc - rtld_argc; for (i = 0; i <= main_argc; i++) argv[i] = argv[i + rtld_argc]; *argcp -= rtld_argc; environ = env = envp = argv + main_argc + 1; dbg("move env from %p to %p", envp + rtld_argc, envp); do { *envp = *(envp + rtld_argc); } while (*envp++ != NULL); aux = auxp = (Elf_Auxinfo *)envp; auxpf = (Elf_Auxinfo *)(envp + rtld_argc); dbg("move aux from %p to %p", auxpf, aux); /* XXXKIB insert place for AT_EXECPATH if not present */ for (;; auxp++, auxpf++) { *auxp = *auxpf; if (auxp->a_type == AT_NULL) break; } /* Since the auxiliary vector has moved, redigest it. */ for (i = 0; i < AT_COUNT; i++) aux_info[i] = NULL; for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { if (auxp->a_type < AT_COUNT) aux_info[auxp->a_type] = auxp; } /* Point AT_EXECPATH auxv and aux_info to the binary path. */ if (binpath == NULL) { aux_info[AT_EXECPATH] = NULL; } else { if (aux_info[AT_EXECPATH] == NULL) { aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; } aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, binpath); } } else { _rtld_error("No binary"); rtld_die(); } } } ld_bind_now = getenv(_LD("BIND_NOW")); /* * If the process is tainted, then we un-set the dangerous environment * variables. The process will be marked as tainted until setuid(2) * is called. If any child process calls setuid(2) we do not want any * future processes to honor the potentially un-safe variables. */ if (!trust) { if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH")) || unsetenv(_LD("PRELOAD_FDS"))) { _rtld_error("environment corrupt; aborting"); rtld_die(); } } ld_debug = getenv(_LD("DEBUG")); if (ld_bind_now == NULL) ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; libmap_override = getenv(_LD("LIBMAP")); ld_library_path = getenv(_LD("LIBRARY_PATH")); ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); ld_preload = getenv(_LD("PRELOAD")); ld_preload_fds = getenv(_LD("PRELOAD_FDS")); ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); if (library_path_rpath != NULL) { if (library_path_rpath[0] == 'y' || library_path_rpath[0] == 'Y' || library_path_rpath[0] == '1') ld_library_path_rpath = true; else ld_library_path_rpath = false; } dangerous_ld_env = libmap_disable || (libmap_override != NULL) || (ld_library_path != NULL) || (ld_preload != NULL) || (ld_elf_hints_path != NULL) || ld_loadfltr; ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); ld_utrace = getenv(_LD("UTRACE")); if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) ld_elf_hints_path = ld_elf_hints_default; if (ld_debug != NULL && *ld_debug != '\0') debug = 1; dbg("%s is initialized, base address = %p", __progname, (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); dbg("RTLD dynamic = %p", obj_rtld.dynamic); dbg("RTLD pltgot = %p", obj_rtld.pltgot); dbg("initializing thread locks"); lockdflt_init(); /* * Load the main program, or process its program header if it is * already loaded. */ if (fd != -1) { /* Load the main program. */ dbg("loading main program"); obj_main = map_object(fd, argv0, NULL); close(fd); if (obj_main == NULL) rtld_die(); max_stack_flags = obj_main->stack_flags; } else { /* Main program already loaded. */ dbg("processing main program's program header"); assert(aux_info[AT_PHDR] != NULL); phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; assert(aux_info[AT_PHNUM] != NULL); phnum = aux_info[AT_PHNUM]->a_un.a_val; assert(aux_info[AT_PHENT] != NULL); assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); assert(aux_info[AT_ENTRY] != NULL); imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) rtld_die(); } if (aux_info[AT_EXECPATH] != NULL && fd == -1) { kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); if (kexecpath[0] == '/') obj_main->path = kexecpath; else if (getcwd(buf, sizeof(buf)) == NULL || strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) obj_main->path = xstrdup(argv0); else obj_main->path = xstrdup(buf); } else { dbg("No AT_EXECPATH or direct exec"); obj_main->path = xstrdup(argv0); } dbg("obj_main path %s", obj_main->path); obj_main->mainprog = true; if (aux_info[AT_STACKPROT] != NULL && aux_info[AT_STACKPROT]->a_un.a_val != 0) stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; #ifndef COMPAT_32BIT /* * Get the actual dynamic linker pathname from the executable if * possible. (It should always be possible.) That ensures that * gdb will find the right dynamic linker even if a non-standard * one is being used. */ if (obj_main->interp != NULL && strcmp(obj_main->interp, obj_rtld.path) != 0) { free(obj_rtld.path); obj_rtld.path = xstrdup(obj_main->interp); __progname = obj_rtld.path; } #endif if (!digest_dynamic(obj_main, 0)) rtld_die(); dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, obj_main->dynsymcount); linkmap_add(obj_main); linkmap_add(&obj_rtld); /* Link the main program into the list of objects. */ TAILQ_INSERT_HEAD(&obj_list, obj_main, next); obj_count++; obj_loads++; /* Initialize a fake symbol for resolving undefined weak references. */ sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); sym_zero.st_shndx = SHN_UNDEF; sym_zero.st_value = -(uintptr_t)obj_main->relocbase; if (!libmap_disable) libmap_disable = (bool)lm_init(libmap_override); dbg("loading LD_PRELOAD_FDS libraries"); if (load_preload_objects(ld_preload_fds, true) == -1) rtld_die(); dbg("loading LD_PRELOAD libraries"); if (load_preload_objects(ld_preload, false) == -1) rtld_die(); preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); dbg("loading needed objects"); if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 0) == -1) rtld_die(); /* Make a list of all objects loaded at startup. */ last_interposer = obj_main; TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker) continue; if (obj->z_interpose && obj != obj_main) { objlist_put_after(&list_main, last_interposer, obj); last_interposer = obj; } else { objlist_push_tail(&list_main, obj); } obj->refcount++; } dbg("checking for required versions"); if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) rtld_die(); if (ld_tracing) { /* We're done */ trace_loaded_objects(obj_main); exit(0); } if (getenv(_LD("DUMP_REL_PRE")) != NULL) { dump_relocations(obj_main); exit (0); } /* * Processing tls relocations requires having the tls offsets * initialized. Prepare offsets before starting initial * relocation processing. */ dbg("initializing initial thread local storage offsets"); STAILQ_FOREACH(entry, &list_main, link) { /* * Allocate all the initial objects out of the static TLS * block even if they didn't ask for it. */ allocate_tls_offset(entry->obj); } if (relocate_objects(obj_main, ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, SYMLOOK_EARLY, NULL) == -1) rtld_die(); dbg("doing copy relocations"); if (do_copy_relocations(obj_main) == -1) rtld_die(); if (getenv(_LD("DUMP_REL_POST")) != NULL) { dump_relocations(obj_main); exit (0); } ifunc_init(aux); /* * Setup TLS for main thread. This must be done after the * relocations are processed, since tls initialization section * might be the subject for relocations. */ dbg("initializing initial thread local storage"); allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); dbg("initializing key program variables"); set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); set_program_var("environ", env); set_program_var("__elf_aux_vector", aux); /* Make a list of init functions to call. */ objlist_init(&initlist); initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), preload_tail, &initlist); r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ map_stacks_exec(NULL); if (!obj_main->crt_no_init) { /* * Make sure we don't call the main program's init and fini * functions for binaries linked with old crt1 which calls * _init itself. */ obj_main->init = obj_main->fini = (Elf_Addr)NULL; obj_main->preinit_array = obj_main->init_array = obj_main->fini_array = (Elf_Addr)NULL; } if (direct_exec) { /* Set osrel for direct-execed binary */ mib[0] = CTL_KERN; mib[1] = KERN_PROC; mib[2] = KERN_PROC_OSREL; mib[3] = getpid(); osrel = obj_main->osrel; sz = sizeof(old_osrel); dbg("setting osrel to %d", osrel); (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); } wlock_acquire(rtld_bind_lock, &lockstate); dbg("resolving ifuncs"); if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) rtld_die(); rtld_exit_ptr = rtld_exit; if (obj_main->crt_no_init) preinit_main(); objlist_call_init(&initlist, &lockstate); _r_debug_postinit(&obj_main->linkmap); objlist_clear(&initlist); dbg("loading filtees"); TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker) continue; if (ld_loadfltr || obj->z_loadfltr) load_filtees(obj, 0, &lockstate); } dbg("enforcing main obj relro"); if (obj_enforce_relro(obj_main) == -1) rtld_die(); lock_release(rtld_bind_lock, &lockstate); dbg("transferring control to program entry point = %p", obj_main->entry); /* Return the exit procedure and the program entry point. */ *exit_proc = rtld_exit_ptr; *objp = obj_main; return (func_ptr_type) obj_main->entry; } void * rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) { void *ptr; Elf_Addr target; ptr = (void *)make_function_pointer(def, obj); target = call_ifunc_resolver(ptr); return ((void *)target); } /* * NB: MIPS uses a private version of this function (_mips_rtld_bind). * Changes to this function should be applied there as well. */ Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff) { const Elf_Rel *rel; const Elf_Sym *def; const Obj_Entry *defobj; Elf_Addr *where; Elf_Addr target; RtldLockState lockstate; rlock_acquire(rtld_bind_lock, &lockstate); if (sigsetjmp(lockstate.env, 0) != 0) lock_upgrade(rtld_bind_lock, &lockstate); if (obj->pltrel) rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); else rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); where = (Elf_Addr *)(obj->relocbase + rel->r_offset); def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, NULL, &lockstate); if (def == NULL) rtld_die(); if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); else target = (Elf_Addr)(defobj->relocbase + def->st_value); dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", defobj->strtab + def->st_name, obj->path == NULL ? NULL : basename(obj->path), (void *)target, defobj->path == NULL ? NULL : basename(defobj->path)); /* * Write the new contents for the jmpslot. Note that depending on * architecture, the value which we need to return back to the * lazy binding trampoline may or may not be the target * address. The value returned from reloc_jmpslot() is the value * that the trampoline needs. */ target = reloc_jmpslot(where, target, defobj, obj, rel); lock_release(rtld_bind_lock, &lockstate); return target; } /* * Error reporting function. Use it like printf. If formats the message * into a buffer, and sets things up so that the next call to dlerror() * will return the message. */ void _rtld_error(const char *fmt, ...) { static char buf[512]; va_list ap; va_start(ap, fmt); rtld_vsnprintf(buf, sizeof buf, fmt, ap); error_message = buf; va_end(ap); LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message); } /* * Return a dynamically-allocated copy of the current error message, if any. */ static char * errmsg_save(void) { return error_message == NULL ? NULL : xstrdup(error_message); } /* * Restore the current error message from a copy which was previously saved * by errmsg_save(). The copy is freed. */ static void errmsg_restore(char *saved_msg) { if (saved_msg == NULL) error_message = NULL; else { _rtld_error("%s", saved_msg); free(saved_msg); } } static const char * basename(const char *name) { const char *p = strrchr(name, '/'); return p != NULL ? p + 1 : name; } static struct utsname uts; static char * origin_subst_one(Obj_Entry *obj, char *real, const char *kw, const char *subst, bool may_free) { char *p, *p1, *res, *resp; int subst_len, kw_len, subst_count, old_len, new_len; kw_len = strlen(kw); /* * First, count the number of the keyword occurrences, to * preallocate the final string. */ for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { p1 = strstr(p, kw); if (p1 == NULL) break; } /* * If the keyword is not found, just return. * * Return non-substituted string if resolution failed. We * cannot do anything more reasonable, the failure mode of the * caller is unresolved library anyway. */ if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) return (may_free ? real : xstrdup(real)); if (obj != NULL) subst = obj->origin_path; /* * There is indeed something to substitute. Calculate the * length of the resulting string, and allocate it. */ subst_len = strlen(subst); old_len = strlen(real); new_len = old_len + (subst_len - kw_len) * subst_count; res = xmalloc(new_len + 1); /* * Now, execute the substitution loop. */ for (p = real, resp = res, *resp = '\0';;) { p1 = strstr(p, kw); if (p1 != NULL) { /* Copy the prefix before keyword. */ memcpy(resp, p, p1 - p); resp += p1 - p; /* Keyword replacement. */ memcpy(resp, subst, subst_len); resp += subst_len; *resp = '\0'; p = p1 + kw_len; } else break; } /* Copy to the end of string and finish. */ strcat(resp, p); if (may_free) free(real); return (res); } static char * origin_subst(Obj_Entry *obj, const char *real) { char *res1, *res2, *res3, *res4; if (obj == NULL || !trust) return (xstrdup(real)); if (uts.sysname[0] == '\0') { if (uname(&uts) != 0) { _rtld_error("utsname failed: %d", errno); return (NULL); } } /* __DECONST is safe here since without may_free real is unchanged */ res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, false); res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); return (res4); } void rtld_die(void) { const char *msg = dlerror(); if (msg == NULL) msg = "Fatal error"; rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); rtld_fdputstr(STDERR_FILENO, msg); rtld_fdputchar(STDERR_FILENO, '\n'); _exit(1); } /* * Process a shared object's DYNAMIC section, and save the important * information in its Obj_Entry structure. */ static void digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) { const Elf_Dyn *dynp; Needed_Entry **needed_tail = &obj->needed; Needed_Entry **needed_filtees_tail = &obj->needed_filtees; Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; const Elf_Hashelt *hashtab; const Elf32_Word *hashval; Elf32_Word bkt, nmaskwords; int bloom_size32; int plttype = DT_REL; *dyn_rpath = NULL; *dyn_soname = NULL; *dyn_runpath = NULL; obj->bind_now = false; dynp = obj->dynamic; if (dynp == NULL) return; for (; dynp->d_tag != DT_NULL; dynp++) { switch (dynp->d_tag) { case DT_REL: obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_RELSZ: obj->relsize = dynp->d_un.d_val; break; case DT_RELENT: assert(dynp->d_un.d_val == sizeof(Elf_Rel)); break; case DT_JMPREL: obj->pltrel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); break; case DT_PLTRELSZ: obj->pltrelsize = dynp->d_un.d_val; break; case DT_RELA: obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_RELASZ: obj->relasize = dynp->d_un.d_val; break; case DT_RELAENT: assert(dynp->d_un.d_val == sizeof(Elf_Rela)); break; case DT_PLTREL: plttype = dynp->d_un.d_val; assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); break; case DT_SYMTAB: obj->symtab = (const Elf_Sym *) (obj->relocbase + dynp->d_un.d_ptr); break; case DT_SYMENT: assert(dynp->d_un.d_val == sizeof(Elf_Sym)); break; case DT_STRTAB: obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_STRSZ: obj->strsize = dynp->d_un.d_val; break; case DT_VERNEED: obj->verneed = (const Elf_Verneed *)(obj->relocbase + dynp->d_un.d_val); break; case DT_VERNEEDNUM: obj->verneednum = dynp->d_un.d_val; break; case DT_VERDEF: obj->verdef = (const Elf_Verdef *)(obj->relocbase + dynp->d_un.d_val); break; case DT_VERDEFNUM: obj->verdefnum = dynp->d_un.d_val; break; case DT_VERSYM: obj->versyms = (const Elf_Versym *)(obj->relocbase + dynp->d_un.d_val); break; case DT_HASH: { hashtab = (const Elf_Hashelt *)(obj->relocbase + dynp->d_un.d_ptr); obj->nbuckets = hashtab[0]; obj->nchains = hashtab[1]; obj->buckets = hashtab + 2; obj->chains = obj->buckets + obj->nbuckets; obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && obj->buckets != NULL; } break; case DT_GNU_HASH: { hashtab = (const Elf_Hashelt *)(obj->relocbase + dynp->d_un.d_ptr); obj->nbuckets_gnu = hashtab[0]; obj->symndx_gnu = hashtab[1]; nmaskwords = hashtab[2]; bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; obj->maskwords_bm_gnu = nmaskwords - 1; obj->shift2_gnu = hashtab[3]; obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); obj->buckets_gnu = hashtab + 4 + bloom_size32; obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - obj->symndx_gnu; /* Number of bitmask words is required to be power of 2 */ obj->valid_hash_gnu = powerof2(nmaskwords) && obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; } break; case DT_NEEDED: if (!obj->rtld) { Needed_Entry *nep = NEW(Needed_Entry); nep->name = dynp->d_un.d_val; nep->obj = NULL; nep->next = NULL; *needed_tail = nep; needed_tail = &nep->next; } break; case DT_FILTER: if (!obj->rtld) { Needed_Entry *nep = NEW(Needed_Entry); nep->name = dynp->d_un.d_val; nep->obj = NULL; nep->next = NULL; *needed_filtees_tail = nep; needed_filtees_tail = &nep->next; if (obj->linkmap.l_refname == NULL) obj->linkmap.l_refname = (char *)dynp->d_un.d_val; } break; case DT_AUXILIARY: if (!obj->rtld) { Needed_Entry *nep = NEW(Needed_Entry); nep->name = dynp->d_un.d_val; nep->obj = NULL; nep->next = NULL; *needed_aux_filtees_tail = nep; needed_aux_filtees_tail = &nep->next; } break; case DT_PLTGOT: obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_TEXTREL: obj->textrel = true; break; case DT_SYMBOLIC: obj->symbolic = true; break; case DT_RPATH: /* * We have to wait until later to process this, because we * might not have gotten the address of the string table yet. */ *dyn_rpath = dynp; break; case DT_SONAME: *dyn_soname = dynp; break; case DT_RUNPATH: *dyn_runpath = dynp; break; case DT_INIT: obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_PREINIT_ARRAY: obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_PREINIT_ARRAYSZ: obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); break; case DT_INIT_ARRAY: obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_INIT_ARRAYSZ: obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); break; case DT_FINI: obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_FINI_ARRAY: obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); break; case DT_FINI_ARRAYSZ: obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); break; /* * Don't process DT_DEBUG on MIPS as the dynamic section * is mapped read-only. DT_MIPS_RLD_MAP is used instead. */ #ifndef __mips__ case DT_DEBUG: if (!early) dbg("Filling in DT_DEBUG entry"); (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; break; #endif case DT_FLAGS: if (dynp->d_un.d_val & DF_ORIGIN) obj->z_origin = true; if (dynp->d_un.d_val & DF_SYMBOLIC) obj->symbolic = true; if (dynp->d_un.d_val & DF_TEXTREL) obj->textrel = true; if (dynp->d_un.d_val & DF_BIND_NOW) obj->bind_now = true; if (dynp->d_un.d_val & DF_STATIC_TLS) obj->static_tls = true; break; #ifdef __mips__ case DT_MIPS_LOCAL_GOTNO: obj->local_gotno = dynp->d_un.d_val; break; case DT_MIPS_SYMTABNO: obj->symtabno = dynp->d_un.d_val; break; case DT_MIPS_GOTSYM: obj->gotsym = dynp->d_un.d_val; break; case DT_MIPS_RLD_MAP: *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; break; case DT_MIPS_RLD_MAP_REL: // The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map // section relative to the address of the tag itself. *((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) = (Elf_Addr) &r_debug; break; case DT_MIPS_PLTGOT: obj->mips_pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); break; #endif #ifdef __powerpc__ #ifdef __powerpc64__ case DT_PPC64_GLINK: obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); break; #else case DT_PPC_GOT: obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); break; #endif #endif case DT_FLAGS_1: if (dynp->d_un.d_val & DF_1_NOOPEN) obj->z_noopen = true; if (dynp->d_un.d_val & DF_1_ORIGIN) obj->z_origin = true; if (dynp->d_un.d_val & DF_1_GLOBAL) obj->z_global = true; if (dynp->d_un.d_val & DF_1_BIND_NOW) obj->bind_now = true; if (dynp->d_un.d_val & DF_1_NODELETE) obj->z_nodelete = true; if (dynp->d_un.d_val & DF_1_LOADFLTR) obj->z_loadfltr = true; if (dynp->d_un.d_val & DF_1_INTERPOSE) obj->z_interpose = true; if (dynp->d_un.d_val & DF_1_NODEFLIB) obj->z_nodeflib = true; if (dynp->d_un.d_val & DF_1_PIE) obj->z_pie = true; break; default: if (!early) { dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, (long)dynp->d_tag); } break; } } obj->traced = false; if (plttype == DT_RELA) { obj->pltrela = (const Elf_Rela *) obj->pltrel; obj->pltrel = NULL; obj->pltrelasize = obj->pltrelsize; obj->pltrelsize = 0; } /* Determine size of dynsym table (equal to nchains of sysv hash) */ if (obj->valid_hash_sysv) obj->dynsymcount = obj->nchains; else if (obj->valid_hash_gnu) { obj->dynsymcount = 0; for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { if (obj->buckets_gnu[bkt] == 0) continue; hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; do obj->dynsymcount++; while ((*hashval++ & 1u) == 0); } obj->dynsymcount += obj->symndx_gnu; } if (obj->linkmap.l_refname != NULL) obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> linkmap.l_refname; } static bool obj_resolve_origin(Obj_Entry *obj) { if (obj->origin_path != NULL) return (true); obj->origin_path = xmalloc(PATH_MAX); return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); } static bool digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) { if (obj->z_origin && !obj_resolve_origin(obj)) return (false); if (dyn_runpath != NULL) { obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; obj->runpath = origin_subst(obj, obj->runpath); } else if (dyn_rpath != NULL) { obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; obj->rpath = origin_subst(obj, obj->rpath); } if (dyn_soname != NULL) object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); return (true); } static bool digest_dynamic(Obj_Entry *obj, int early) { const Elf_Dyn *dyn_rpath; const Elf_Dyn *dyn_soname; const Elf_Dyn *dyn_runpath; digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); } /* * Process a shared object's program header. This is used only for the * main program, when the kernel has already loaded the main program * into memory before calling the dynamic linker. It creates and * returns an Obj_Entry structure. */ static Obj_Entry * digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) { Obj_Entry *obj; const Elf_Phdr *phlimit = phdr + phnum; const Elf_Phdr *ph; Elf_Addr note_start, note_end; int nsegs = 0; obj = obj_new(); for (ph = phdr; ph < phlimit; ph++) { if (ph->p_type != PT_PHDR) continue; obj->phdr = phdr; obj->phsize = ph->p_memsz; obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; break; } obj->stack_flags = PF_X | PF_R | PF_W; for (ph = phdr; ph < phlimit; ph++) { switch (ph->p_type) { case PT_INTERP: obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); break; case PT_LOAD: if (nsegs == 0) { /* First load segment */ obj->vaddrbase = trunc_page(ph->p_vaddr); obj->mapbase = obj->vaddrbase + obj->relocbase; } else { /* Last load segment */ obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - obj->vaddrbase; } nsegs++; break; case PT_DYNAMIC: obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); break; case PT_TLS: obj->tlsindex = 1; obj->tlssize = ph->p_memsz; obj->tlsalign = ph->p_align; obj->tlsinitsize = ph->p_filesz; obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); obj->tlspoffset = ph->p_offset; break; case PT_GNU_STACK: obj->stack_flags = ph->p_flags; break; case PT_GNU_RELRO: obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); obj->relro_size = round_page(ph->p_memsz); break; case PT_NOTE: note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; note_end = note_start + ph->p_filesz; digest_notes(obj, note_start, note_end); break; } } if (nsegs < 1) { _rtld_error("%s: too few PT_LOAD segments", path); return NULL; } obj->entry = entry; return obj; } void digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) { const Elf_Note *note; const char *note_name; uintptr_t p; for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; note = (const Elf_Note *)((const char *)(note + 1) + roundup2(note->n_namesz, sizeof(Elf32_Addr)) + roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || note->n_descsz != sizeof(int32_t)) continue; if (note->n_type != NT_FREEBSD_ABI_TAG && note->n_type != NT_FREEBSD_FEATURE_CTL && note->n_type != NT_FREEBSD_NOINIT_TAG) continue; note_name = (const char *)(note + 1); if (strncmp(NOTE_FREEBSD_VENDOR, note_name, sizeof(NOTE_FREEBSD_VENDOR)) != 0) continue; switch (note->n_type) { case NT_FREEBSD_ABI_TAG: /* FreeBSD osrel note */ p = (uintptr_t)(note + 1); p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); obj->osrel = *(const int32_t *)(p); dbg("note osrel %d", obj->osrel); break; case NT_FREEBSD_FEATURE_CTL: /* FreeBSD ABI feature control note */ p = (uintptr_t)(note + 1); p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); obj->fctl0 = *(const uint32_t *)(p); dbg("note fctl0 %#x", obj->fctl0); break; case NT_FREEBSD_NOINIT_TAG: /* FreeBSD 'crt does not call init' note */ obj->crt_no_init = true; dbg("note crt_no_init"); break; } } } static Obj_Entry * dlcheck(void *handle) { Obj_Entry *obj; TAILQ_FOREACH(obj, &obj_list, next) { if (obj == (Obj_Entry *) handle) break; } if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { _rtld_error("Invalid shared object handle %p", handle); return NULL; } return obj; } /* * If the given object is already in the donelist, return true. Otherwise * add the object to the list and return false. */ static bool donelist_check(DoneList *dlp, const Obj_Entry *obj) { unsigned int i; for (i = 0; i < dlp->num_used; i++) if (dlp->objs[i] == obj) return true; /* * Our donelist allocation should always be sufficient. But if * our threads locking isn't working properly, more shared objects * could have been loaded since we allocated the list. That should * never happen, but we'll handle it properly just in case it does. */ if (dlp->num_used < dlp->num_alloc) dlp->objs[dlp->num_used++] = obj; return false; } /* * Hash function for symbol table lookup. Don't even think about changing * this. It is specified by the System V ABI. */ unsigned long elf_hash(const char *name) { const unsigned char *p = (const unsigned char *) name; unsigned long h = 0; unsigned long g; while (*p != '\0') { h = (h << 4) + *p++; if ((g = h & 0xf0000000) != 0) h ^= g >> 24; h &= ~g; } return h; } /* * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits * unsigned in case it's implemented with a wider type. */ static uint32_t gnu_hash(const char *s) { uint32_t h; unsigned char c; h = 5381; for (c = *s; c != '\0'; c = *++s) h = h * 33 + c; return (h & 0xffffffff); } /* * Find the library with the given name, and return its full pathname. * The returned string is dynamically allocated. Generates an error * message and returns NULL if the library cannot be found. * * If the second argument is non-NULL, then it refers to an already- * loaded shared object, whose library search path will be searched. * * If a library is successfully located via LD_LIBRARY_PATH_FDS, its * descriptor (which is close-on-exec) will be passed out via the third * argument. * * The search order is: * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) * LD_LIBRARY_PATH * DT_RUNPATH in the referencing file * ldconfig hints (if -z nodefaultlib, filter out default library directories * from list) * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib * * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. */ static char * find_library(const char *xname, const Obj_Entry *refobj, int *fdp) { char *pathname, *refobj_path; const char *name; bool nodeflib, objgiven; objgiven = refobj != NULL; if (libmap_disable || !objgiven || (name = lm_find(refobj->path, xname)) == NULL) name = xname; if (strchr(name, '/') != NULL) { /* Hard coded pathname */ if (name[0] != '/' && !trust) { _rtld_error("Absolute pathname required " "for shared object \"%s\"", name); return (NULL); } return (origin_subst(__DECONST(Obj_Entry *, refobj), __DECONST(char *, name))); } dbg(" Searching for \"%s\"", name); refobj_path = objgiven ? refobj->path : NULL; /* * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall * back to pre-conforming behaviour if user requested so with * LD_LIBRARY_PATH_RPATH environment variable and ignore -z * nodeflib. */ if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { pathname = search_library_path(name, ld_library_path, refobj_path, fdp); if (pathname != NULL) return (pathname); if (refobj != NULL) { pathname = search_library_path(name, refobj->rpath, refobj_path, fdp); if (pathname != NULL) return (pathname); } pathname = search_library_pathfds(name, ld_library_dirs, fdp); if (pathname != NULL) return (pathname); pathname = search_library_path(name, gethints(false), refobj_path, fdp); if (pathname != NULL) return (pathname); pathname = search_library_path(name, ld_standard_library_path, refobj_path, fdp); if (pathname != NULL) return (pathname); } else { nodeflib = objgiven ? refobj->z_nodeflib : false; if (objgiven) { pathname = search_library_path(name, refobj->rpath, refobj->path, fdp); if (pathname != NULL) return (pathname); } if (objgiven && refobj->runpath == NULL && refobj != obj_main) { pathname = search_library_path(name, obj_main->rpath, refobj_path, fdp); if (pathname != NULL) return (pathname); } pathname = search_library_path(name, ld_library_path, refobj_path, fdp); if (pathname != NULL) return (pathname); if (objgiven) { pathname = search_library_path(name, refobj->runpath, refobj_path, fdp); if (pathname != NULL) return (pathname); } pathname = search_library_pathfds(name, ld_library_dirs, fdp); if (pathname != NULL) return (pathname); pathname = search_library_path(name, gethints(nodeflib), refobj_path, fdp); if (pathname != NULL) return (pathname); if (objgiven && !nodeflib) { pathname = search_library_path(name, ld_standard_library_path, refobj_path, fdp); if (pathname != NULL) return (pathname); } } if (objgiven && refobj->path != NULL) { _rtld_error("Shared object \"%s\" not found, " "required by \"%s\"", name, basename(refobj->path)); } else { _rtld_error("Shared object \"%s\" not found", name); } return (NULL); } /* * Given a symbol number in a referencing object, find the corresponding * definition of the symbol. Returns a pointer to the symbol, or NULL if * no definition was found. Returns a pointer to the Obj_Entry of the * defining object via the reference parameter DEFOBJ_OUT. */ const Elf_Sym * find_symdef(unsigned long symnum, const Obj_Entry *refobj, const Obj_Entry **defobj_out, int flags, SymCache *cache, RtldLockState *lockstate) { const Elf_Sym *ref; const Elf_Sym *def; const Obj_Entry *defobj; const Ver_Entry *ve; SymLook req; const char *name; int res; /* * If we have already found this symbol, get the information from * the cache. */ if (symnum >= refobj->dynsymcount) return NULL; /* Bad object */ if (cache != NULL && cache[symnum].sym != NULL) { *defobj_out = cache[symnum].obj; return cache[symnum].sym; } ref = refobj->symtab + symnum; name = refobj->strtab + ref->st_name; def = NULL; defobj = NULL; ve = NULL; /* * We don't have to do a full scale lookup if the symbol is local. * We know it will bind to the instance in this load module; to * which we already have a pointer (ie ref). By not doing a lookup, * we not only improve performance, but it also avoids unresolvable * symbols when local symbols are not in the hash table. This has * been seen with the ia64 toolchain. */ if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, symnum); } symlook_init(&req, name); req.flags = flags; ve = req.ventry = fetch_ventry(refobj, symnum); req.lockstate = lockstate; res = symlook_default(&req, refobj); if (res == 0) { def = req.sym_out; defobj = req.defobj_out; } } else { def = ref; defobj = refobj; } /* * If we found no definition and the reference is weak, treat the * symbol as having the value zero. */ if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { def = &sym_zero; defobj = obj_main; } if (def != NULL) { *defobj_out = defobj; /* Record the information in the cache to avoid subsequent lookups. */ if (cache != NULL) { cache[symnum].sym = def; cache[symnum].obj = defobj; } } else { if (refobj != &obj_rtld) _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); } return def; } /* * Return the search path from the ldconfig hints file, reading it if * necessary. If nostdlib is true, then the default search paths are * not added to result. * * Returns NULL if there are problems with the hints file, * or if the search path there is empty. */ static const char * gethints(bool nostdlib) { static char *filtered_path; static const char *hints; static struct elfhints_hdr hdr; struct fill_search_info_args sargs, hargs; struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; struct dl_serpath *SLPpath, *hintpath; char *p; struct stat hint_stat; unsigned int SLPndx, hintndx, fndx, fcount; int fd; size_t flen; uint32_t dl; bool skip; /* First call, read the hints file */ if (hints == NULL) { /* Keep from trying again in case the hints file is bad. */ hints = ""; if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) return (NULL); /* * Check of hdr.dirlistlen value against type limit * intends to pacify static analyzers. Further * paranoia leads to checks that dirlist is fully * contained in the file range. */ if (read(fd, &hdr, sizeof hdr) != sizeof hdr || hdr.magic != ELFHINTS_MAGIC || hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || fstat(fd, &hint_stat) == -1) { cleanup1: close(fd); hdr.dirlistlen = 0; return (NULL); } dl = hdr.strtab; if (dl + hdr.dirlist < dl) goto cleanup1; dl += hdr.dirlist; if (dl + hdr.dirlistlen < dl) goto cleanup1; dl += hdr.dirlistlen; if (dl > hint_stat.st_size) goto cleanup1; p = xmalloc(hdr.dirlistlen + 1); if (pread(fd, p, hdr.dirlistlen + 1, hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || p[hdr.dirlistlen] != '\0') { free(p); goto cleanup1; } hints = p; close(fd); } /* * If caller agreed to receive list which includes the default * paths, we are done. Otherwise, if we still did not * calculated filtered result, do it now. */ if (!nostdlib) return (hints[0] != '\0' ? hints : NULL); if (filtered_path != NULL) goto filt_ret; /* * Obtain the list of all configured search paths, and the * list of the default paths. * * First estimate the size of the results. */ smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); smeta.dls_cnt = 0; hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); hmeta.dls_cnt = 0; sargs.request = RTLD_DI_SERINFOSIZE; sargs.serinfo = &smeta; hargs.request = RTLD_DI_SERINFOSIZE; hargs.serinfo = &hmeta; path_enumerate(ld_standard_library_path, fill_search_info, NULL, &sargs); path_enumerate(hints, fill_search_info, NULL, &hargs); SLPinfo = xmalloc(smeta.dls_size); hintinfo = xmalloc(hmeta.dls_size); /* * Next fetch both sets of paths. */ sargs.request = RTLD_DI_SERINFO; sargs.serinfo = SLPinfo; sargs.serpath = &SLPinfo->dls_serpath[0]; sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; hargs.request = RTLD_DI_SERINFO; hargs.serinfo = hintinfo; hargs.serpath = &hintinfo->dls_serpath[0]; hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; path_enumerate(ld_standard_library_path, fill_search_info, NULL, &sargs); path_enumerate(hints, fill_search_info, NULL, &hargs); /* * Now calculate the difference between two sets, by excluding * standard paths from the full set. */ fndx = 0; fcount = 0; filtered_path = xmalloc(hdr.dirlistlen + 1); hintpath = &hintinfo->dls_serpath[0]; for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { skip = false; SLPpath = &SLPinfo->dls_serpath[0]; /* * Check each standard path against current. */ for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { /* matched, skip the path */ if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { skip = true; break; } } if (skip) continue; /* * Not matched against any standard path, add the path * to result. Separate consequtive paths with ':'. */ if (fcount > 0) { filtered_path[fndx] = ':'; fndx++; } fcount++; flen = strlen(hintpath->dls_name); strncpy((filtered_path + fndx), hintpath->dls_name, flen); fndx += flen; } filtered_path[fndx] = '\0'; free(SLPinfo); free(hintinfo); filt_ret: return (filtered_path[0] != '\0' ? filtered_path : NULL); } static void init_dag(Obj_Entry *root) { const Needed_Entry *needed; const Objlist_Entry *elm; DoneList donelist; if (root->dag_inited) return; donelist_init(&donelist); /* Root object belongs to own DAG. */ objlist_push_tail(&root->dldags, root); objlist_push_tail(&root->dagmembers, root); donelist_check(&donelist, root); /* * Add dependencies of root object to DAG in breadth order * by exploiting the fact that each new object get added * to the tail of the dagmembers list. */ STAILQ_FOREACH(elm, &root->dagmembers, link) { for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) continue; objlist_push_tail(&needed->obj->dldags, root); objlist_push_tail(&root->dagmembers, needed->obj); } } root->dag_inited = true; } static void init_marker(Obj_Entry *marker) { bzero(marker, sizeof(*marker)); marker->marker = true; } Obj_Entry * globallist_curr(const Obj_Entry *obj) { for (;;) { if (obj == NULL) return (NULL); if (!obj->marker) return (__DECONST(Obj_Entry *, obj)); obj = TAILQ_PREV(obj, obj_entry_q, next); } } Obj_Entry * globallist_next(const Obj_Entry *obj) { for (;;) { obj = TAILQ_NEXT(obj, next); if (obj == NULL) return (NULL); if (!obj->marker) return (__DECONST(Obj_Entry *, obj)); } } /* Prevent the object from being unmapped while the bind lock is dropped. */ static void hold_object(Obj_Entry *obj) { obj->holdcount++; } static void unhold_object(Obj_Entry *obj) { assert(obj->holdcount > 0); if (--obj->holdcount == 0 && obj->unholdfree) release_object(obj); } static void process_z(Obj_Entry *root) { const Objlist_Entry *elm; Obj_Entry *obj; /* * Walk over object DAG and process every dependent object * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need * to grow their own DAG. * * For DF_1_GLOBAL, DAG is required for symbol lookups in * symlook_global() to work. * * For DF_1_NODELETE, the DAG should have its reference upped. */ STAILQ_FOREACH(elm, &root->dagmembers, link) { obj = elm->obj; if (obj == NULL) continue; if (obj->z_nodelete && !obj->ref_nodel) { dbg("obj %s -z nodelete", obj->path); init_dag(obj); ref_dag(obj); obj->ref_nodel = true; } if (obj->z_global && objlist_find(&list_global, obj) == NULL) { dbg("obj %s -z global", obj->path); objlist_push_tail(&list_global, obj); init_dag(obj); } } } static void parse_rtld_phdr(Obj_Entry *obj) { const Elf_Phdr *ph; Elf_Addr note_start, note_end; obj->stack_flags = PF_X | PF_R | PF_W; for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + obj->phsize; ph++) { switch (ph->p_type) { case PT_GNU_STACK: obj->stack_flags = ph->p_flags; break; case PT_GNU_RELRO: obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); obj->relro_size = round_page(ph->p_memsz); break; case PT_NOTE: note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; note_end = note_start + ph->p_filesz; digest_notes(obj, note_start, note_end); break; } } } /* * Initialize the dynamic linker. The argument is the address at which * the dynamic linker has been mapped into memory. The primary task of * this function is to relocate the dynamic linker. */ static void init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) { Obj_Entry objtmp; /* Temporary rtld object */ const Elf_Ehdr *ehdr; const Elf_Dyn *dyn_rpath; const Elf_Dyn *dyn_soname; const Elf_Dyn *dyn_runpath; #ifdef RTLD_INIT_PAGESIZES_EARLY /* The page size is required by the dynamic memory allocator. */ init_pagesizes(aux_info); #endif /* * Conjure up an Obj_Entry structure for the dynamic linker. * * The "path" member can't be initialized yet because string constants * cannot yet be accessed. Below we will set it correctly. */ memset(&objtmp, 0, sizeof(objtmp)); objtmp.path = NULL; objtmp.rtld = true; objtmp.mapbase = mapbase; #ifdef PIC objtmp.relocbase = mapbase; #endif objtmp.dynamic = rtld_dynamic(&objtmp); digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); assert(objtmp.needed == NULL); #if !defined(__mips__) /* MIPS has a bogus DT_TEXTREL. */ assert(!objtmp.textrel); #endif /* * Temporarily put the dynamic linker entry into the object list, so * that symbols can be found. */ relocate_objects(&objtmp, true, &objtmp, 0, NULL); ehdr = (Elf_Ehdr *)mapbase; objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); /* Initialize the object list. */ TAILQ_INIT(&obj_list); /* Now that non-local variables can be accesses, copy out obj_rtld. */ memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); #ifndef RTLD_INIT_PAGESIZES_EARLY /* The page size is required by the dynamic memory allocator. */ init_pagesizes(aux_info); #endif if (aux_info[AT_OSRELDATE] != NULL) osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); /* Replace the path with a dynamically allocated copy. */ obj_rtld.path = xstrdup(ld_path_rtld); parse_rtld_phdr(&obj_rtld); obj_enforce_relro(&obj_rtld); r_debug.r_version = R_DEBUG_VERSION; r_debug.r_brk = r_debug_state; r_debug.r_state = RT_CONSISTENT; r_debug.r_ldbase = obj_rtld.relocbase; } /* * Retrieve the array of supported page sizes. The kernel provides the page * sizes in increasing order. */ static void init_pagesizes(Elf_Auxinfo **aux_info) { static size_t psa[MAXPAGESIZES]; int mib[2]; size_t len, size; if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != NULL) { size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; } else { len = 2; if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) size = sizeof(psa); else { /* As a fallback, retrieve the base page size. */ size = sizeof(psa[0]); if (aux_info[AT_PAGESZ] != NULL) { psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; goto psa_filled; } else { mib[0] = CTL_HW; mib[1] = HW_PAGESIZE; len = 2; } } if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { _rtld_error("sysctl for hw.pagesize(s) failed"); rtld_die(); } psa_filled: pagesizes = psa; } npagesizes = size / sizeof(pagesizes[0]); /* Discard any invalid entries at the end of the array. */ while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) npagesizes--; } /* * Add the init functions from a needed object list (and its recursive * needed objects) to "list". This is not used directly; it is a helper * function for initlist_add_objects(). The write lock must be held * when this function is called. */ static void initlist_add_neededs(Needed_Entry *needed, Objlist *list) { /* Recursively process the successor needed objects. */ if (needed->next != NULL) initlist_add_neededs(needed->next, list); /* Process the current needed object. */ if (needed->obj != NULL) initlist_add_objects(needed->obj, needed->obj, list); } /* * Scan all of the DAGs rooted in the range of objects from "obj" to * "tail" and add their init functions to "list". This recurses over * the DAGs and ensure the proper init ordering such that each object's * needed libraries are initialized before the object itself. At the * same time, this function adds the objects to the global finalization * list "list_fini" in the opposite order. The write lock must be * held when this function is called. */ static void initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) { Obj_Entry *nobj; if (obj->init_scanned || obj->init_done) return; obj->init_scanned = true; /* Recursively process the successor objects. */ nobj = globallist_next(obj); if (nobj != NULL && obj != tail) initlist_add_objects(nobj, tail, list); /* Recursively process the needed objects. */ if (obj->needed != NULL) initlist_add_neededs(obj->needed, list); if (obj->needed_filtees != NULL) initlist_add_neededs(obj->needed_filtees, list); if (obj->needed_aux_filtees != NULL) initlist_add_neededs(obj->needed_aux_filtees, list); /* Add the object to the init list. */ objlist_push_tail(list, obj); /* Add the object to the global fini list in the reverse order. */ if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) && !obj->on_fini_list) { objlist_push_head(&list_fini, obj); obj->on_fini_list = true; } } #ifndef FPTR_TARGET #define FPTR_TARGET(f) ((Elf_Addr) (f)) #endif static void free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) { Needed_Entry *needed, *needed1; for (needed = n; needed != NULL; needed = needed->next) { if (needed->obj != NULL) { dlclose_locked(needed->obj, lockstate); needed->obj = NULL; } } for (needed = n; needed != NULL; needed = needed1) { needed1 = needed->next; free(needed); } } static void unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) { free_needed_filtees(obj->needed_filtees, lockstate); obj->needed_filtees = NULL; free_needed_filtees(obj->needed_aux_filtees, lockstate); obj->needed_aux_filtees = NULL; obj->filtees_loaded = false; } static void load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, RtldLockState *lockstate) { for (; needed != NULL; needed = needed->next) { needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | RTLD_LOCAL, lockstate); } } static void load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) { lock_restart_for_upgrade(lockstate); if (!obj->filtees_loaded) { load_filtee1(obj, obj->needed_filtees, flags, lockstate); load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); obj->filtees_loaded = true; } } static int process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) { Obj_Entry *obj1; for (; needed != NULL; needed = needed->next) { obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, flags & ~RTLD_LO_NOLOAD); if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) return (-1); } return (0); } /* * Given a shared object, traverse its list of needed objects, and load * each of them. Returns 0 on success. Generates an error message and * returns -1 on failure. */ static int load_needed_objects(Obj_Entry *first, int flags) { Obj_Entry *obj; for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { if (obj->marker) continue; if (process_needed(obj, obj->needed, flags) == -1) return (-1); } return (0); } static int load_preload_objects(char *p, bool isfd) { Obj_Entry *obj; static const char delim[] = " \t:;"; if (p == NULL) return (0); p += strspn(p, delim); while (*p != '\0') { const char *name; size_t len = strcspn(p, delim); char savech; int fd; savech = p[len]; p[len] = '\0'; if (isfd) { name = NULL; fd = parse_integer(p); if (fd == -1) return (-1); } else { name = p; fd = -1; } obj = load_object(name, fd, NULL, 0); if (obj == NULL) return (-1); /* XXX - cleanup */ obj->z_interpose = true; p[len] = savech; p += len; p += strspn(p, delim); } LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); return (0); } static const char * printable_path(const char *path) { return (path == NULL ? "" : path); } /* * Load a shared object into memory, if it is not already loaded. The * object may be specified by name or by user-supplied file descriptor * fd_u. In the later case, the fd_u descriptor is not closed, but its * duplicate is. * * Returns a pointer to the Obj_Entry for the object. Returns NULL * on failure. */ static Obj_Entry * load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) { Obj_Entry *obj; int fd; struct stat sb; char *path; fd = -1; if (name != NULL) { TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker || obj->doomed) continue; if (object_match_name(obj, name)) return (obj); } path = find_library(name, refobj, &fd); if (path == NULL) return (NULL); } else path = NULL; if (fd >= 0) { /* * search_library_pathfds() opens a fresh file descriptor for the * library, so there is no need to dup(). */ } else if (fd_u == -1) { /* * If we didn't find a match by pathname, or the name is not * supplied, open the file and check again by device and inode. * This avoids false mismatches caused by multiple links or ".." * in pathnames. * * To avoid a race, we open the file and use fstat() rather than * using stat(). */ if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { _rtld_error("Cannot open \"%s\"", path); free(path); return (NULL); } } else { fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); if (fd == -1) { _rtld_error("Cannot dup fd"); free(path); return (NULL); } } if (fstat(fd, &sb) == -1) { _rtld_error("Cannot fstat \"%s\"", printable_path(path)); close(fd); free(path); return NULL; } TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker || obj->doomed) continue; if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) break; } if (obj != NULL && name != NULL) { object_add_name(obj, name); free(path); close(fd); return obj; } if (flags & RTLD_LO_NOLOAD) { free(path); close(fd); return (NULL); } /* First use of this object, so we must map it in */ obj = do_load_object(fd, name, path, &sb, flags); if (obj == NULL) free(path); close(fd); return obj; } static Obj_Entry * do_load_object(int fd, const char *name, char *path, struct stat *sbp, int flags) { Obj_Entry *obj; struct statfs fs; /* * but first, make sure that environment variables haven't been * used to circumvent the noexec flag on a filesystem. */ if (dangerous_ld_env) { if (fstatfs(fd, &fs) != 0) { _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); return NULL; } if (fs.f_flags & MNT_NOEXEC) { _rtld_error("Cannot execute objects on %s", fs.f_mntonname); return NULL; } } dbg("loading \"%s\"", printable_path(path)); obj = map_object(fd, printable_path(path), sbp); if (obj == NULL) return NULL; /* * If DT_SONAME is present in the object, digest_dynamic2 already * added it to the object names. */ if (name != NULL) object_add_name(obj, name); obj->path = path; if (!digest_dynamic(obj, 0)) goto errp; dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { dbg("refusing to load PIE executable \"%s\"", obj->path); _rtld_error("Cannot load PIE binary %s as DSO", obj->path); goto errp; } if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { dbg("refusing to load non-loadable \"%s\"", obj->path); _rtld_error("Cannot dlopen non-loadable %s", obj->path); goto errp; } obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; TAILQ_INSERT_TAIL(&obj_list, obj, next); obj_count++; obj_loads++; linkmap_add(obj); /* for GDB & dlinfo() */ max_stack_flags |= obj->stack_flags; dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, obj->path); if (obj->textrel) dbg(" WARNING: %s has impure text", obj->path); LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, obj->path); return (obj); errp: munmap(obj->mapbase, obj->mapsize); obj_free(obj); return (NULL); } static Obj_Entry * obj_from_addr(const void *addr) { Obj_Entry *obj; TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker) continue; if (addr < (void *) obj->mapbase) continue; if (addr < (void *)(obj->mapbase + obj->mapsize)) return obj; } return NULL; } static void preinit_main(void) { Elf_Addr *preinit_addr; int index; preinit_addr = (Elf_Addr *)obj_main->preinit_array; if (preinit_addr == NULL) return; for (index = 0; index < obj_main->preinit_array_num; index++) { if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { dbg("calling preinit function for %s at %p", obj_main->path, (void *)preinit_addr[index]); LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 0, 0, obj_main->path); call_init_pointer(obj_main, preinit_addr[index]); } } } /* * Call the finalization functions for each of the objects in "list" * belonging to the DAG of "root" and referenced once. If NULL "root" * is specified, every finalization function will be called regardless * of the reference count and the list elements won't be freed. All of * the objects are expected to have non-NULL fini functions. */ static void objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) { Objlist_Entry *elm; char *saved_msg; Elf_Addr *fini_addr; int index; assert(root == NULL || root->refcount == 1); if (root != NULL) root->doomed = true; /* * Preserve the current error message since a fini function might * call into the dynamic linker and overwrite it. */ saved_msg = errmsg_save(); do { STAILQ_FOREACH(elm, list, link) { if (root != NULL && (elm->obj->refcount != 1 || objlist_find(&root->dagmembers, elm->obj) == NULL)) continue; /* Remove object from fini list to prevent recursive invocation. */ STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); /* Ensure that new references cannot be acquired. */ elm->obj->doomed = true; hold_object(elm->obj); lock_release(rtld_bind_lock, lockstate); /* * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. * When this happens, DT_FINI_ARRAY is processed first. */ fini_addr = (Elf_Addr *)elm->obj->fini_array; if (fini_addr != NULL && elm->obj->fini_array_num > 0) { for (index = elm->obj->fini_array_num - 1; index >= 0; index--) { if (fini_addr[index] != 0 && fini_addr[index] != 1) { dbg("calling fini function for %s at %p", elm->obj->path, (void *)fini_addr[index]); LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)fini_addr[index], 0, 0, elm->obj->path); call_initfini_pointer(elm->obj, fini_addr[index]); } } } if (elm->obj->fini != (Elf_Addr)NULL) { dbg("calling fini function for %s at %p", elm->obj->path, (void *)elm->obj->fini); LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0, elm->obj->path); call_initfini_pointer(elm->obj, elm->obj->fini); } wlock_acquire(rtld_bind_lock, lockstate); unhold_object(elm->obj); /* No need to free anything if process is going down. */ if (root != NULL) free(elm); /* * We must restart the list traversal after every fini call * because a dlclose() call from the fini function or from * another thread might have modified the reference counts. */ break; } } while (elm != NULL); errmsg_restore(saved_msg); } /* * Call the initialization functions for each of the objects in * "list". All of the objects are expected to have non-NULL init * functions. */ static void objlist_call_init(Objlist *list, RtldLockState *lockstate) { Objlist_Entry *elm; Obj_Entry *obj; char *saved_msg; Elf_Addr *init_addr; void (*reg)(void (*)(void)); int index; /* * Clean init_scanned flag so that objects can be rechecked and * possibly initialized earlier if any of vectors called below * cause the change by using dlopen. */ TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker) continue; obj->init_scanned = false; } /* * Preserve the current error message since an init function might * call into the dynamic linker and overwrite it. */ saved_msg = errmsg_save(); STAILQ_FOREACH(elm, list, link) { if (elm->obj->init_done) /* Initialized early. */ continue; /* * Race: other thread might try to use this object before current * one completes the initialization. Not much can be done here * without better locking. */ elm->obj->init_done = true; hold_object(elm->obj); reg = NULL; if (elm->obj == obj_main && obj_main->crt_no_init) { reg = (void (*)(void (*)(void)))get_program_var_addr( "__libc_atexit", lockstate); } lock_release(rtld_bind_lock, lockstate); if (reg != NULL) { reg(rtld_exit); rtld_exit_ptr = rtld_nop_exit; } /* * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. * When this happens, DT_INIT is processed first. */ if (elm->obj->init != (Elf_Addr)NULL) { dbg("calling init function for %s at %p", elm->obj->path, (void *)elm->obj->init); LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0, elm->obj->path); call_init_pointer(elm->obj, elm->obj->init); } init_addr = (Elf_Addr *)elm->obj->init_array; if (init_addr != NULL) { for (index = 0; index < elm->obj->init_array_num; index++) { if (init_addr[index] != 0 && init_addr[index] != 1) { dbg("calling init function for %s at %p", elm->obj->path, (void *)init_addr[index]); LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)init_addr[index], 0, 0, elm->obj->path); call_init_pointer(elm->obj, init_addr[index]); } } } wlock_acquire(rtld_bind_lock, lockstate); unhold_object(elm->obj); } errmsg_restore(saved_msg); } static void objlist_clear(Objlist *list) { Objlist_Entry *elm; while (!STAILQ_EMPTY(list)) { elm = STAILQ_FIRST(list); STAILQ_REMOVE_HEAD(list, link); free(elm); } } static Objlist_Entry * objlist_find(Objlist *list, const Obj_Entry *obj) { Objlist_Entry *elm; STAILQ_FOREACH(elm, list, link) if (elm->obj == obj) return elm; return NULL; } static void objlist_init(Objlist *list) { STAILQ_INIT(list); } static void objlist_push_head(Objlist *list, Obj_Entry *obj) { Objlist_Entry *elm; elm = NEW(Objlist_Entry); elm->obj = obj; STAILQ_INSERT_HEAD(list, elm, link); } static void objlist_push_tail(Objlist *list, Obj_Entry *obj) { Objlist_Entry *elm; elm = NEW(Objlist_Entry); elm->obj = obj; STAILQ_INSERT_TAIL(list, elm, link); } static void objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) { Objlist_Entry *elm, *listelm; STAILQ_FOREACH(listelm, list, link) { if (listelm->obj == listobj) break; } elm = NEW(Objlist_Entry); elm->obj = obj; if (listelm != NULL) STAILQ_INSERT_AFTER(list, listelm, elm, link); else STAILQ_INSERT_TAIL(list, elm, link); } static void objlist_remove(Objlist *list, Obj_Entry *obj) { Objlist_Entry *elm; if ((elm = objlist_find(list, obj)) != NULL) { STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); free(elm); } } /* * Relocate dag rooted in the specified object. * Returns 0 on success, or -1 on failure. */ static int relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, int flags, RtldLockState *lockstate) { Objlist_Entry *elm; int error; error = 0; STAILQ_FOREACH(elm, &root->dagmembers, link) { error = relocate_object(elm->obj, bind_now, rtldobj, flags, lockstate); if (error == -1) break; } return (error); } /* * Prepare for, or clean after, relocating an object marked with * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only * segments are remapped read-write. After relocations are done, the * segment's permissions are returned back to the modes specified in * the phdrs. If any relocation happened, or always for wired * program, COW is triggered. */ static int reloc_textrel_prot(Obj_Entry *obj, bool before) { const Elf_Phdr *ph; void *base; size_t l, sz; int prot; for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; l--, ph++) { if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) continue; base = obj->relocbase + trunc_page(ph->p_vaddr); sz = round_page(ph->p_vaddr + ph->p_filesz) - trunc_page(ph->p_vaddr); prot = before ? (PROT_READ | PROT_WRITE) : convert_prot(ph->p_flags); if (mprotect(base, sz, prot) == -1) { _rtld_error("%s: Cannot write-%sable text segment: %s", obj->path, before ? "en" : "dis", rtld_strerror(errno)); return (-1); } } return (0); } /* * Relocate single object. * Returns 0 on success, or -1 on failure. */ static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, RtldLockState *lockstate) { if (obj->relocated) return (0); obj->relocated = true; if (obj != rtldobj) dbg("relocating \"%s\"", obj->path); if (obj->symtab == NULL || obj->strtab == NULL || !(obj->valid_hash_sysv || obj->valid_hash_gnu)) dbg("object %s has no run-time symbol table", obj->path); /* There are relocations to the write-protected text segment. */ if (obj->textrel && reloc_textrel_prot(obj, true) != 0) return (-1); /* Process the non-PLT non-IFUNC relocations. */ if (reloc_non_plt(obj, rtldobj, flags, lockstate)) return (-1); /* Re-protected the text segment. */ if (obj->textrel && reloc_textrel_prot(obj, false) != 0) return (-1); /* Set the special PLT or GOT entries. */ init_pltgot(obj); /* Process the PLT relocations. */ if (reloc_plt(obj, flags, lockstate) == -1) return (-1); /* Relocate the jump slots if we are doing immediate binding. */ if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, lockstate) == -1) return (-1); if (!obj->mainprog && obj_enforce_relro(obj) == -1) return (-1); /* * Set up the magic number and version in the Obj_Entry. These * were checked in the crt1.o from the original ElfKit, so we * set them for backward compatibility. */ obj->magic = RTLD_MAGIC; obj->version = RTLD_VERSION; return (0); } /* * Relocate newly-loaded shared objects. The argument is a pointer to * the Obj_Entry for the first such object. All objects from the first * to the end of the list of objects are relocated. Returns 0 on success, * or -1 on failure. */ static int relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, RtldLockState *lockstate) { Obj_Entry *obj; int error; for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { if (obj->marker) continue; error = relocate_object(obj, bind_now, rtldobj, flags, lockstate); if (error == -1) break; } return (error); } /* * The handling of R_MACHINE_IRELATIVE relocations and jumpslots * referencing STT_GNU_IFUNC symbols is postponed till the other * relocations are done. The indirect functions specified as * ifunc are allowed to call other symbols, so we need to have * objects relocated before asking for resolution from indirects. * * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, * instead of the usual lazy handling of PLT slots. It is * consistent with how GNU does it. */ static int resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, RtldLockState *lockstate) { if (obj->ifuncs_resolved) return (0); obj->ifuncs_resolved = true; if (!obj->irelative && !obj->irelative_nonplt && !((obj->bind_now || bind_now) && obj->gnu_ifunc) && !obj->non_plt_gnu_ifunc) return (0); if (obj_disable_relro(obj) == -1 || (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, lockstate) == -1) || ((obj->bind_now || bind_now) && obj->gnu_ifunc && reloc_gnu_ifunc(obj, flags, lockstate) == -1) || (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, lockstate) == -1) || obj_enforce_relro(obj) == -1) return (-1); return (0); } static int initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, RtldLockState *lockstate) { Objlist_Entry *elm; Obj_Entry *obj; STAILQ_FOREACH(elm, list, link) { obj = elm->obj; if (obj->marker) continue; if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) return (-1); } return (0); } /* * Cleanup procedure. It will be called (by the atexit mechanism) just * before the process exits. */ static void rtld_exit(void) { RtldLockState lockstate; wlock_acquire(rtld_bind_lock, &lockstate); dbg("rtld_exit()"); objlist_call_fini(&list_fini, NULL, &lockstate); /* No need to remove the items from the list, since we are exiting. */ if (!libmap_disable) lm_fini(); lock_release(rtld_bind_lock, &lockstate); } static void rtld_nop_exit(void) { } /* * Iterate over a search path, translate each element, and invoke the * callback on the result. */ static void * path_enumerate(const char *path, path_enum_proc callback, const char *refobj_path, void *arg) { const char *trans; if (path == NULL) return (NULL); path += strspn(path, ":;"); while (*path != '\0') { size_t len; char *res; len = strcspn(path, ":;"); trans = lm_findn(refobj_path, path, len); if (trans) res = callback(trans, strlen(trans), arg); else res = callback(path, len, arg); if (res != NULL) return (res); path += len; path += strspn(path, ":;"); } return (NULL); } struct try_library_args { const char *name; size_t namelen; char *buffer; size_t buflen; int fd; }; static void * try_library_path(const char *dir, size_t dirlen, void *param) { struct try_library_args *arg; int fd; arg = param; if (*dir == '/' || trust) { char *pathname; if (dirlen + 1 + arg->namelen + 1 > arg->buflen) return (NULL); pathname = arg->buffer; strncpy(pathname, dir, dirlen); pathname[dirlen] = '/'; strcpy(pathname + dirlen + 1, arg->name); dbg(" Trying \"%s\"", pathname); fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); if (fd >= 0) { dbg(" Opened \"%s\", fd %d", pathname, fd); pathname = xmalloc(dirlen + 1 + arg->namelen + 1); strcpy(pathname, arg->buffer); arg->fd = fd; return (pathname); } else { dbg(" Failed to open \"%s\": %s", pathname, rtld_strerror(errno)); } } return (NULL); } static char * search_library_path(const char *name, const char *path, const char *refobj_path, int *fdp) { char *p; struct try_library_args arg; if (path == NULL) return NULL; arg.name = name; arg.namelen = strlen(name); arg.buffer = xmalloc(PATH_MAX); arg.buflen = PATH_MAX; arg.fd = -1; p = path_enumerate(path, try_library_path, refobj_path, &arg); *fdp = arg.fd; free(arg.buffer); return (p); } /* * Finds the library with the given name using the directory descriptors * listed in the LD_LIBRARY_PATH_FDS environment variable. * * Returns a freshly-opened close-on-exec file descriptor for the library, * or -1 if the library cannot be found. */ static char * search_library_pathfds(const char *name, const char *path, int *fdp) { char *envcopy, *fdstr, *found, *last_token; size_t len; int dirfd, fd; dbg("%s('%s', '%s', fdp)", __func__, name, path); /* Don't load from user-specified libdirs into setuid binaries. */ if (!trust) return (NULL); /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ if (path == NULL) return (NULL); /* LD_LIBRARY_PATH_FDS only works with relative paths. */ if (name[0] == '/') { dbg("Absolute path (%s) passed to %s", name, __func__); return (NULL); } /* * Use strtok_r() to walk the FD:FD:FD list. This requires a local * copy of the path, as strtok_r rewrites separator tokens * with '\0'. */ found = NULL; envcopy = xstrdup(path); for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; fdstr = strtok_r(NULL, ":", &last_token)) { dirfd = parse_integer(fdstr); if (dirfd < 0) { _rtld_error("failed to parse directory FD: '%s'", fdstr); break; } fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); if (fd >= 0) { *fdp = fd; len = strlen(fdstr) + strlen(name) + 3; found = xmalloc(len); if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { _rtld_error("error generating '%d/%s'", dirfd, name); rtld_die(); } dbg("open('%s') => %d", found, fd); break; } } free(envcopy); return (found); } int dlclose(void *handle) { RtldLockState lockstate; int error; wlock_acquire(rtld_bind_lock, &lockstate); error = dlclose_locked(handle, &lockstate); lock_release(rtld_bind_lock, &lockstate); return (error); } static int dlclose_locked(void *handle, RtldLockState *lockstate) { Obj_Entry *root; root = dlcheck(handle); if (root == NULL) return -1; LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, root->path); /* Unreference the object and its dependencies. */ root->dl_refcount--; if (root->refcount == 1) { /* * The object will be no longer referenced, so we must unload it. * First, call the fini functions. */ objlist_call_fini(&list_fini, root, lockstate); unref_dag(root); /* Finish cleaning up the newly-unreferenced objects. */ GDB_STATE(RT_DELETE,&root->linkmap); unload_object(root, lockstate); GDB_STATE(RT_CONSISTENT,NULL); } else unref_dag(root); LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); return 0; } char * dlerror(void) { char *msg = error_message; error_message = NULL; return msg; } /* * This function is deprecated and has no effect. */ void dllockinit(void *context, void *(*_lock_create)(void *context) __unused, void (*_rlock_acquire)(void *lock) __unused, void (*_wlock_acquire)(void *lock) __unused, void (*_lock_release)(void *lock) __unused, void (*_lock_destroy)(void *lock) __unused, void (*context_destroy)(void *context)) { static void *cur_context; static void (*cur_context_destroy)(void *); /* Just destroy the context from the previous call, if necessary. */ if (cur_context_destroy != NULL) cur_context_destroy(cur_context); cur_context = context; cur_context_destroy = context_destroy; } void * dlopen(const char *name, int mode) { return (rtld_dlopen(name, -1, mode)); } void * fdlopen(int fd, int mode) { return (rtld_dlopen(NULL, fd, mode)); } static void * rtld_dlopen(const char *name, int fd, int mode) { RtldLockState lockstate; int lo_flags; LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; if (ld_tracing != NULL) { rlock_acquire(rtld_bind_lock, &lockstate); if (sigsetjmp(lockstate.env, 0) != 0) lock_upgrade(rtld_bind_lock, &lockstate); environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); lock_release(rtld_bind_lock, &lockstate); } lo_flags = RTLD_LO_DLOPEN; if (mode & RTLD_NODELETE) lo_flags |= RTLD_LO_NODELETE; if (mode & RTLD_NOLOAD) lo_flags |= RTLD_LO_NOLOAD; if (mode & RTLD_DEEPBIND) lo_flags |= RTLD_LO_DEEPBIND; if (ld_tracing != NULL) lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; return (dlopen_object(name, fd, obj_main, lo_flags, mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); } static void dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) { obj->dl_refcount--; unref_dag(obj); if (obj->refcount == 0) unload_object(obj, lockstate); } static Obj_Entry * dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, int mode, RtldLockState *lockstate) { Obj_Entry *old_obj_tail; Obj_Entry *obj; Objlist initlist; RtldLockState mlockstate; int result; dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", name != NULL ? name : "", fd, refobj == NULL ? "" : refobj->path, lo_flags, mode); objlist_init(&initlist); if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { wlock_acquire(rtld_bind_lock, &mlockstate); lockstate = &mlockstate; } GDB_STATE(RT_ADD,NULL); old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); obj = NULL; if (name == NULL && fd == -1) { obj = obj_main; obj->refcount++; } else { obj = load_object(name, fd, refobj, lo_flags); } if (obj) { obj->dl_refcount++; if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) objlist_push_tail(&list_global, obj); if (globallist_next(old_obj_tail) != NULL) { /* We loaded something new. */ assert(globallist_next(old_obj_tail) == obj); if ((lo_flags & RTLD_LO_DEEPBIND) != 0) obj->symbolic = true; result = 0; if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && obj->static_tls && !allocate_tls_offset(obj)) { _rtld_error("%s: No space available " "for static Thread Local Storage", obj->path); result = -1; } if (result != -1) result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); init_dag(obj); ref_dag(obj); if (result != -1) result = rtld_verify_versions(&obj->dagmembers); if (result != -1 && ld_tracing) goto trace; if (result == -1 || relocate_object_dag(obj, (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, lockstate) == -1) { dlopen_cleanup(obj, lockstate); obj = NULL; } else if (lo_flags & RTLD_LO_EARLY) { /* * Do not call the init functions for early loaded * filtees. The image is still not initialized enough * for them to work. * * Our object is found by the global object list and * will be ordered among all init calls done right * before transferring control to main. */ } else { /* Make list of init functions to call. */ initlist_add_objects(obj, obj, &initlist); } /* * Process all no_delete or global objects here, given * them own DAGs to prevent their dependencies from being * unloaded. This has to be done after we have loaded all * of the dependencies, so that we do not miss any. */ if (obj != NULL) process_z(obj); } else { /* * Bump the reference counts for objects on this DAG. If * this is the first dlopen() call for the object that was * already loaded as a dependency, initialize the dag * starting at it. */ init_dag(obj); ref_dag(obj); if ((lo_flags & RTLD_LO_TRACE) != 0) goto trace; } if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && !obj->ref_nodel) { dbg("obj %s nodelete", obj->path); ref_dag(obj); obj->z_nodelete = obj->ref_nodel = true; } } LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, name); GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); if ((lo_flags & RTLD_LO_EARLY) == 0) { map_stacks_exec(lockstate); if (obj != NULL) distribute_static_tls(&initlist, lockstate); } if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, lockstate) == -1) { objlist_clear(&initlist); dlopen_cleanup(obj, lockstate); if (lockstate == &mlockstate) lock_release(rtld_bind_lock, lockstate); return (NULL); } if (!(lo_flags & RTLD_LO_EARLY)) { /* Call the init functions. */ objlist_call_init(&initlist, lockstate); } objlist_clear(&initlist); if (lockstate == &mlockstate) lock_release(rtld_bind_lock, lockstate); return obj; trace: trace_loaded_objects(obj); if (lockstate == &mlockstate) lock_release(rtld_bind_lock, lockstate); exit(0); } static void * do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, int flags) { DoneList donelist; const Obj_Entry *obj, *defobj; const Elf_Sym *def; SymLook req; RtldLockState lockstate; tls_index ti; void *sym; int res; def = NULL; defobj = NULL; symlook_init(&req, name); req.ventry = ve; req.flags = flags | SYMLOOK_IN_PLT; req.lockstate = &lockstate; LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); rlock_acquire(rtld_bind_lock, &lockstate); if (sigsetjmp(lockstate.env, 0) != 0) lock_upgrade(rtld_bind_lock, &lockstate); if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || handle == RTLD_SELF) { if ((obj = obj_from_addr(retaddr)) == NULL) { _rtld_error("Cannot determine caller's shared object"); lock_release(rtld_bind_lock, &lockstate); LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); return NULL; } if (handle == NULL) { /* Just the caller's shared object. */ res = symlook_obj(&req, obj); if (res == 0) { def = req.sym_out; defobj = req.defobj_out; } } else if (handle == RTLD_NEXT || /* Objects after caller's */ handle == RTLD_SELF) { /* ... caller included */ if (handle == RTLD_NEXT) obj = globallist_next(obj); for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { if (obj->marker) continue; res = symlook_obj(&req, obj); if (res == 0) { if (def == NULL || ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { def = req.sym_out; defobj = req.defobj_out; if (ELF_ST_BIND(def->st_info) != STB_WEAK) break; } } } /* * Search the dynamic linker itself, and possibly resolve the * symbol from there. This is how the application links to * dynamic linker services such as dlopen. */ if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { res = symlook_obj(&req, &obj_rtld); if (res == 0) { def = req.sym_out; defobj = req.defobj_out; } } } else { assert(handle == RTLD_DEFAULT); res = symlook_default(&req, obj); if (res == 0) { defobj = req.defobj_out; def = req.sym_out; } } } else { if ((obj = dlcheck(handle)) == NULL) { lock_release(rtld_bind_lock, &lockstate); LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); return NULL; } donelist_init(&donelist); if (obj->mainprog) { /* Handle obtained by dlopen(NULL, ...) implies global scope. */ res = symlook_global(&req, &donelist); if (res == 0) { def = req.sym_out; defobj = req.defobj_out; } /* * Search the dynamic linker itself, and possibly resolve the * symbol from there. This is how the application links to * dynamic linker services such as dlopen. */ if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { res = symlook_obj(&req, &obj_rtld); if (res == 0) { def = req.sym_out; defobj = req.defobj_out; } } } else { /* Search the whole DAG rooted at the given object. */ res = symlook_list(&req, &obj->dagmembers, &donelist); if (res == 0) { def = req.sym_out; defobj = req.defobj_out; } } } if (def != NULL) { lock_release(rtld_bind_lock, &lockstate); /* * The value required by the caller is derived from the value * of the symbol. this is simply the relocated value of the * symbol. */ if (ELF_ST_TYPE(def->st_info) == STT_FUNC) sym = make_function_pointer(def, defobj); else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) sym = rtld_resolve_ifunc(defobj, def); else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { ti.ti_module = defobj->tlsindex; ti.ti_offset = def->st_value; sym = __tls_get_addr(&ti); } else sym = defobj->relocbase + def->st_value; LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); return (sym); } _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); lock_release(rtld_bind_lock, &lockstate); LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); return NULL; } void * dlsym(void *handle, const char *name) { return do_dlsym(handle, name, __builtin_return_address(0), NULL, SYMLOOK_DLSYM); } dlfunc_t dlfunc(void *handle, const char *name) { union { void *d; dlfunc_t f; } rv; rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, SYMLOOK_DLSYM); return (rv.f); } void * dlvsym(void *handle, const char *name, const char *version) { Ver_Entry ventry; ventry.name = version; ventry.file = NULL; ventry.hash = elf_hash(version); ventry.flags= 0; return do_dlsym(handle, name, __builtin_return_address(0), &ventry, SYMLOOK_DLSYM); } int _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) { const Obj_Entry *obj; RtldLockState lockstate; rlock_acquire(rtld_bind_lock, &lockstate); obj = obj_from_addr(addr); if (obj == NULL) { _rtld_error("No shared object contains address"); lock_release(rtld_bind_lock, &lockstate); return (0); } rtld_fill_dl_phdr_info(obj, phdr_info); lock_release(rtld_bind_lock, &lockstate); return (1); } int dladdr(const void *addr, Dl_info *info) { const Obj_Entry *obj; const Elf_Sym *def; void *symbol_addr; unsigned long symoffset; RtldLockState lockstate; rlock_acquire(rtld_bind_lock, &lockstate); obj = obj_from_addr(addr); if (obj == NULL) { _rtld_error("No shared object contains address"); lock_release(rtld_bind_lock, &lockstate); return 0; } info->dli_fname = obj->path; info->dli_fbase = obj->mapbase; info->dli_saddr = (void *)0; info->dli_sname = NULL; /* * Walk the symbol list looking for the symbol whose address is * closest to the address sent in. */ for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { def = obj->symtab + symoffset; /* * For skip the symbol if st_shndx is either SHN_UNDEF or * SHN_COMMON. */ if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) continue; /* * If the symbol is greater than the specified address, or if it * is further away from addr than the current nearest symbol, * then reject it. */ symbol_addr = obj->relocbase + def->st_value; if (symbol_addr > addr || symbol_addr < info->dli_saddr) continue; /* Update our idea of the nearest symbol. */ info->dli_sname = obj->strtab + def->st_name; info->dli_saddr = symbol_addr; /* Exact match? */ if (info->dli_saddr == addr) break; } lock_release(rtld_bind_lock, &lockstate); return 1; } int dlinfo(void *handle, int request, void *p) { const Obj_Entry *obj; RtldLockState lockstate; int error; rlock_acquire(rtld_bind_lock, &lockstate); if (handle == NULL || handle == RTLD_SELF) { void *retaddr; retaddr = __builtin_return_address(0); /* __GNUC__ only */ if ((obj = obj_from_addr(retaddr)) == NULL) _rtld_error("Cannot determine caller's shared object"); } else obj = dlcheck(handle); if (obj == NULL) { lock_release(rtld_bind_lock, &lockstate); return (-1); } error = 0; switch (request) { case RTLD_DI_LINKMAP: *((struct link_map const **)p) = &obj->linkmap; break; case RTLD_DI_ORIGIN: error = rtld_dirname(obj->path, p); break; case RTLD_DI_SERINFOSIZE: case RTLD_DI_SERINFO: error = do_search_info(obj, request, (struct dl_serinfo *)p); break; default: _rtld_error("Invalid request %d passed to dlinfo()", request); error = -1; } lock_release(rtld_bind_lock, &lockstate); return (error); } static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) { + tls_index ti; phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; phdr_info->dlpi_name = obj->path; phdr_info->dlpi_phdr = obj->phdr; phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); phdr_info->dlpi_tls_modid = obj->tlsindex; - phdr_info->dlpi_tls_data = obj->tlsinit; + ti.ti_module = obj->tlsindex; + ti.ti_offset = 0; + phdr_info->dlpi_tls_data = __tls_get_addr(&ti); phdr_info->dlpi_adds = obj_loads; phdr_info->dlpi_subs = obj_loads - obj_count; } int dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) { struct dl_phdr_info phdr_info; Obj_Entry *obj, marker; RtldLockState bind_lockstate, phdr_lockstate; int error; init_marker(&marker); error = 0; wlock_acquire(rtld_phdr_lock, &phdr_lockstate); wlock_acquire(rtld_bind_lock, &bind_lockstate); for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); rtld_fill_dl_phdr_info(obj, &phdr_info); hold_object(obj); lock_release(rtld_bind_lock, &bind_lockstate); error = callback(&phdr_info, sizeof phdr_info, param); wlock_acquire(rtld_bind_lock, &bind_lockstate); unhold_object(obj); obj = globallist_next(&marker); TAILQ_REMOVE(&obj_list, &marker, next); if (error != 0) { lock_release(rtld_bind_lock, &bind_lockstate); lock_release(rtld_phdr_lock, &phdr_lockstate); return (error); } } if (error == 0) { rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); lock_release(rtld_bind_lock, &bind_lockstate); error = callback(&phdr_info, sizeof(phdr_info), param); } lock_release(rtld_phdr_lock, &phdr_lockstate); return (error); } static void * fill_search_info(const char *dir, size_t dirlen, void *param) { struct fill_search_info_args *arg; arg = param; if (arg->request == RTLD_DI_SERINFOSIZE) { arg->serinfo->dls_cnt ++; arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; } else { struct dl_serpath *s_entry; s_entry = arg->serpath; s_entry->dls_name = arg->strspace; s_entry->dls_flags = arg->flags; strncpy(arg->strspace, dir, dirlen); arg->strspace[dirlen] = '\0'; arg->strspace += dirlen + 1; arg->serpath++; } return (NULL); } static int do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) { struct dl_serinfo _info; struct fill_search_info_args args; args.request = RTLD_DI_SERINFOSIZE; args.serinfo = &_info; _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); _info.dls_cnt = 0; path_enumerate(obj->rpath, fill_search_info, NULL, &args); path_enumerate(ld_library_path, fill_search_info, NULL, &args); path_enumerate(obj->runpath, fill_search_info, NULL, &args); path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); if (!obj->z_nodeflib) path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); if (request == RTLD_DI_SERINFOSIZE) { info->dls_size = _info.dls_size; info->dls_cnt = _info.dls_cnt; return (0); } if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); return (-1); } args.request = RTLD_DI_SERINFO; args.serinfo = info; args.serpath = &info->dls_serpath[0]; args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; args.flags = LA_SER_RUNPATH; if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) return (-1); args.flags = LA_SER_LIBPATH; if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) return (-1); args.flags = LA_SER_RUNPATH; if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) return (-1); args.flags = LA_SER_CONFIG; if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) != NULL) return (-1); args.flags = LA_SER_DEFAULT; if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args) != NULL) return (-1); return (0); } static int rtld_dirname(const char *path, char *bname) { const char *endp; /* Empty or NULL string gets treated as "." */ if (path == NULL || *path == '\0') { bname[0] = '.'; bname[1] = '\0'; return (0); } /* Strip trailing slashes */ endp = path + strlen(path) - 1; while (endp > path && *endp == '/') endp--; /* Find the start of the dir */ while (endp > path && *endp != '/') endp--; /* Either the dir is "/" or there are no slashes */ if (endp == path) { bname[0] = *endp == '/' ? '/' : '.'; bname[1] = '\0'; return (0); } else { do { endp--; } while (endp > path && *endp == '/'); } if (endp - path + 2 > PATH_MAX) { _rtld_error("Filename is too long: %s", path); return(-1); } strncpy(bname, path, endp - path + 1); bname[endp - path + 1] = '\0'; return (0); } static int rtld_dirname_abs(const char *path, char *base) { char *last; if (realpath(path, base) == NULL) { _rtld_error("realpath \"%s\" failed (%s)", path, rtld_strerror(errno)); return (-1); } dbg("%s -> %s", path, base); last = strrchr(base, '/'); if (last == NULL) { _rtld_error("non-abs result from realpath \"%s\"", path); return (-1); } if (last != base) *last = '\0'; return (0); } static void linkmap_add(Obj_Entry *obj) { struct link_map *l, *prev; l = &obj->linkmap; l->l_name = obj->path; l->l_base = obj->mapbase; l->l_ld = obj->dynamic; l->l_addr = obj->relocbase; if (r_debug.r_map == NULL) { r_debug.r_map = l; return; } /* * Scan to the end of the list, but not past the entry for the * dynamic linker, which we want to keep at the very end. */ for (prev = r_debug.r_map; prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; prev = prev->l_next) ; /* Link in the new entry. */ l->l_prev = prev; l->l_next = prev->l_next; if (l->l_next != NULL) l->l_next->l_prev = l; prev->l_next = l; } static void linkmap_delete(Obj_Entry *obj) { struct link_map *l; l = &obj->linkmap; if (l->l_prev == NULL) { if ((r_debug.r_map = l->l_next) != NULL) l->l_next->l_prev = NULL; return; } if ((l->l_prev->l_next = l->l_next) != NULL) l->l_next->l_prev = l->l_prev; } /* * Function for the debugger to set a breakpoint on to gain control. * * The two parameters allow the debugger to easily find and determine * what the runtime loader is doing and to whom it is doing it. * * When the loadhook trap is hit (r_debug_state, set at program * initialization), the arguments can be found on the stack: * * +8 struct link_map *m * +4 struct r_debug *rd * +0 RetAddr */ void r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) { /* * The following is a hack to force the compiler to emit calls to * this function, even when optimizing. If the function is empty, * the compiler is not obliged to emit any code for calls to it, * even when marked __noinline. However, gdb depends on those * calls being made. */ __compiler_membar(); } /* * A function called after init routines have completed. This can be used to * break before a program's entry routine is called, and can be used when * main is not available in the symbol table. */ void _r_debug_postinit(struct link_map *m __unused) { /* See r_debug_state(). */ __compiler_membar(); } static void release_object(Obj_Entry *obj) { if (obj->holdcount > 0) { obj->unholdfree = true; return; } munmap(obj->mapbase, obj->mapsize); linkmap_delete(obj); obj_free(obj); } /* * Get address of the pointer variable in the main program. * Prefer non-weak symbol over the weak one. */ static const void ** get_program_var_addr(const char *name, RtldLockState *lockstate) { SymLook req; DoneList donelist; symlook_init(&req, name); req.lockstate = lockstate; donelist_init(&donelist); if (symlook_global(&req, &donelist) != 0) return (NULL); if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) return ((const void **)make_function_pointer(req.sym_out, req.defobj_out)); else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); else return ((const void **)(req.defobj_out->relocbase + req.sym_out->st_value)); } /* * Set a pointer variable in the main program to the given value. This * is used to set key variables such as "environ" before any of the * init functions are called. */ static void set_program_var(const char *name, const void *value) { const void **addr; if ((addr = get_program_var_addr(name, NULL)) != NULL) { dbg("\"%s\": *%p <-- %p", name, addr, value); *addr = value; } } /* * Search the global objects, including dependencies and main object, * for the given symbol. */ static int symlook_global(SymLook *req, DoneList *donelist) { SymLook req1; const Objlist_Entry *elm; int res; symlook_init_from_req(&req1, req); /* Search all objects loaded at program start up. */ if (req->defobj_out == NULL || ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { res = symlook_list(&req1, &list_main, donelist); if (res == 0 && (req->defobj_out == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; assert(req->defobj_out != NULL); } } /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ STAILQ_FOREACH(elm, &list_global, link) { if (req->defobj_out != NULL && ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) break; res = symlook_list(&req1, &elm->obj->dagmembers, donelist); if (res == 0 && (req->defobj_out == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; assert(req->defobj_out != NULL); } } return (req->sym_out != NULL ? 0 : ESRCH); } /* * Given a symbol name in a referencing object, find the corresponding * definition of the symbol. Returns a pointer to the symbol, or NULL if * no definition was found. Returns a pointer to the Obj_Entry of the * defining object via the reference parameter DEFOBJ_OUT. */ static int symlook_default(SymLook *req, const Obj_Entry *refobj) { DoneList donelist; const Objlist_Entry *elm; SymLook req1; int res; donelist_init(&donelist); symlook_init_from_req(&req1, req); /* * Look first in the referencing object if linked symbolically, * and similarly handle protected symbols. */ res = symlook_obj(&req1, refobj); if (res == 0 && (refobj->symbolic || ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; assert(req->defobj_out != NULL); } if (refobj->symbolic || req->defobj_out != NULL) donelist_check(&donelist, refobj); symlook_global(req, &donelist); /* Search all dlopened DAGs containing the referencing object. */ STAILQ_FOREACH(elm, &refobj->dldags, link) { if (req->sym_out != NULL && ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) break; res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); if (res == 0 && (req->sym_out == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; assert(req->defobj_out != NULL); } } /* * Search the dynamic linker itself, and possibly resolve the * symbol from there. This is how the application links to * dynamic linker services such as dlopen. */ if (req->sym_out == NULL || ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { res = symlook_obj(&req1, &obj_rtld); if (res == 0) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; assert(req->defobj_out != NULL); } } return (req->sym_out != NULL ? 0 : ESRCH); } static int symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) { const Elf_Sym *def; const Obj_Entry *defobj; const Objlist_Entry *elm; SymLook req1; int res; def = NULL; defobj = NULL; STAILQ_FOREACH(elm, objlist, link) { if (donelist_check(dlp, elm->obj)) continue; symlook_init_from_req(&req1, req); if ((res = symlook_obj(&req1, elm->obj)) == 0) { if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { def = req1.sym_out; defobj = req1.defobj_out; if (ELF_ST_BIND(def->st_info) != STB_WEAK) break; } } } if (def != NULL) { req->sym_out = def; req->defobj_out = defobj; return (0); } return (ESRCH); } /* * Search the chain of DAGS cointed to by the given Needed_Entry * for a symbol of the given name. Each DAG is scanned completely * before advancing to the next one. Returns a pointer to the symbol, * or NULL if no definition was found. */ static int symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) { const Elf_Sym *def; const Needed_Entry *n; const Obj_Entry *defobj; SymLook req1; int res; def = NULL; defobj = NULL; symlook_init_from_req(&req1, req); for (n = needed; n != NULL; n = n->next) { if (n->obj == NULL || (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) continue; if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { def = req1.sym_out; defobj = req1.defobj_out; if (ELF_ST_BIND(def->st_info) != STB_WEAK) break; } } if (def != NULL) { req->sym_out = def; req->defobj_out = defobj; return (0); } return (ESRCH); } /* * Search the symbol table of a single shared object for a symbol of * the given name and version, if requested. Returns a pointer to the * symbol, or NULL if no definition was found. If the object is * filter, return filtered symbol from filtee. * * The symbol's hash value is passed in for efficiency reasons; that * eliminates many recomputations of the hash value. */ int symlook_obj(SymLook *req, const Obj_Entry *obj) { DoneList donelist; SymLook req1; int flags, res, mres; /* * If there is at least one valid hash at this point, we prefer to * use the faster GNU version if available. */ if (obj->valid_hash_gnu) mres = symlook_obj1_gnu(req, obj); else if (obj->valid_hash_sysv) mres = symlook_obj1_sysv(req, obj); else return (EINVAL); if (mres == 0) { if (obj->needed_filtees != NULL) { flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); donelist_init(&donelist); symlook_init_from_req(&req1, req); res = symlook_needed(&req1, obj->needed_filtees, &donelist); if (res == 0) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; } return (res); } if (obj->needed_aux_filtees != NULL) { flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); donelist_init(&donelist); symlook_init_from_req(&req1, req); res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); if (res == 0) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; return (res); } } } return (mres); } /* Symbol match routine common to both hash functions */ static bool matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, const unsigned long symnum) { Elf_Versym verndx; const Elf_Sym *symp; const char *strp; symp = obj->symtab + symnum; strp = obj->strtab + symp->st_name; switch (ELF_ST_TYPE(symp->st_info)) { case STT_FUNC: case STT_NOTYPE: case STT_OBJECT: case STT_COMMON: case STT_GNU_IFUNC: if (symp->st_value == 0) return (false); /* fallthrough */ case STT_TLS: if (symp->st_shndx != SHN_UNDEF) break; #ifndef __mips__ else if (((req->flags & SYMLOOK_IN_PLT) == 0) && (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) break; #endif /* fallthrough */ default: return (false); } if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) return (false); if (req->ventry == NULL) { if (obj->versyms != NULL) { verndx = VER_NDX(obj->versyms[symnum]); if (verndx > obj->vernum) { _rtld_error( "%s: symbol %s references wrong version %d", obj->path, obj->strtab + symnum, verndx); return (false); } /* * If we are not called from dlsym (i.e. this * is a normal relocation from unversioned * binary), accept the symbol immediately if * it happens to have first version after this * shared object became versioned. Otherwise, * if symbol is versioned and not hidden, * remember it. If it is the only symbol with * this name exported by the shared object, it * will be returned as a match by the calling * function. If symbol is global (verndx < 2) * accept it unconditionally. */ if ((req->flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN) { result->sym_out = symp; return (true); } else if (verndx >= VER_NDX_GIVEN) { if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) { if (result->vsymp == NULL) result->vsymp = symp; result->vcount++; } return (false); } } result->sym_out = symp; return (true); } if (obj->versyms == NULL) { if (object_match_name(obj, req->ventry->name)) { _rtld_error("%s: object %s should provide version %s " "for symbol %s", obj_rtld.path, obj->path, req->ventry->name, obj->strtab + symnum); return (false); } } else { verndx = VER_NDX(obj->versyms[symnum]); if (verndx > obj->vernum) { _rtld_error("%s: symbol %s references wrong version %d", obj->path, obj->strtab + symnum, verndx); return (false); } if (obj->vertab[verndx].hash != req->ventry->hash || strcmp(obj->vertab[verndx].name, req->ventry->name)) { /* * Version does not match. Look if this is a * global symbol and if it is not hidden. If * global symbol (verndx < 2) is available, * use it. Do not return symbol if we are * called by dlvsym, because dlvsym looks for * a specific version and default one is not * what dlvsym wants. */ if ((req->flags & SYMLOOK_DLSYM) || (verndx >= VER_NDX_GIVEN) || (obj->versyms[symnum] & VER_NDX_HIDDEN)) return (false); } } result->sym_out = symp; return (true); } /* * Search for symbol using SysV hash function. * obj->buckets is known not to be NULL at this point; the test for this was * performed with the obj->valid_hash_sysv assignment. */ static int symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) { unsigned long symnum; Sym_Match_Result matchres; matchres.sym_out = NULL; matchres.vsymp = NULL; matchres.vcount = 0; for (symnum = obj->buckets[req->hash % obj->nbuckets]; symnum != STN_UNDEF; symnum = obj->chains[symnum]) { if (symnum >= obj->nchains) return (ESRCH); /* Bad object */ if (matched_symbol(req, obj, &matchres, symnum)) { req->sym_out = matchres.sym_out; req->defobj_out = obj; return (0); } } if (matchres.vcount == 1) { req->sym_out = matchres.vsymp; req->defobj_out = obj; return (0); } return (ESRCH); } /* Search for symbol using GNU hash function */ static int symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) { Elf_Addr bloom_word; const Elf32_Word *hashval; Elf32_Word bucket; Sym_Match_Result matchres; unsigned int h1, h2; unsigned long symnum; matchres.sym_out = NULL; matchres.vsymp = NULL; matchres.vcount = 0; /* Pick right bitmask word from Bloom filter array */ bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & obj->maskwords_bm_gnu]; /* Calculate modulus word size of gnu hash and its derivative */ h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); /* Filter out the "definitely not in set" queries */ if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) return (ESRCH); /* Locate hash chain and corresponding value element*/ bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; if (bucket == 0) return (ESRCH); hashval = &obj->chain_zero_gnu[bucket]; do { if (((*hashval ^ req->hash_gnu) >> 1) == 0) { symnum = hashval - obj->chain_zero_gnu; if (matched_symbol(req, obj, &matchres, symnum)) { req->sym_out = matchres.sym_out; req->defobj_out = obj; return (0); } } } while ((*hashval++ & 1) == 0); if (matchres.vcount == 1) { req->sym_out = matchres.vsymp; req->defobj_out = obj; return (0); } return (ESRCH); } static void trace_loaded_objects(Obj_Entry *obj) { const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; int c; if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) main_local = ""; if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) fmt1 = "\t%o => %p (%x)\n"; if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) fmt2 = "\t%o (%x)\n"; list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { Needed_Entry *needed; const char *name, *path; bool is_lib; if (obj->marker) continue; if (list_containers && obj->needed != NULL) rtld_printf("%s:\n", obj->path); for (needed = obj->needed; needed; needed = needed->next) { if (needed->obj != NULL) { if (needed->obj->traced && !list_containers) continue; needed->obj->traced = true; path = needed->obj->path; } else path = "not found"; name = obj->strtab + needed->name; is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ fmt = is_lib ? fmt1 : fmt2; while ((c = *fmt++) != '\0') { switch (c) { default: rtld_putchar(c); continue; case '\\': switch (c = *fmt) { case '\0': continue; case 'n': rtld_putchar('\n'); break; case 't': rtld_putchar('\t'); break; } break; case '%': switch (c = *fmt) { case '\0': continue; case '%': default: rtld_putchar(c); break; case 'A': rtld_putstr(main_local); break; case 'a': rtld_putstr(obj_main->path); break; case 'o': rtld_putstr(name); break; #if 0 case 'm': rtld_printf("%d", sodp->sod_major); break; case 'n': rtld_printf("%d", sodp->sod_minor); break; #endif case 'p': rtld_putstr(path); break; case 'x': rtld_printf("%p", needed->obj ? needed->obj->mapbase : 0); break; } break; } ++fmt; } } } } /* * Unload a dlopened object and its dependencies from memory and from * our data structures. It is assumed that the DAG rooted in the * object has already been unreferenced, and that the object has a * reference count of 0. */ static void unload_object(Obj_Entry *root, RtldLockState *lockstate) { Obj_Entry marker, *obj, *next; assert(root->refcount == 0); /* * Pass over the DAG removing unreferenced objects from * appropriate lists. */ unlink_object(root); /* Unmap all objects that are no longer referenced. */ for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { next = TAILQ_NEXT(obj, next); if (obj->marker || obj->refcount != 0) continue; LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, obj->path); dbg("unloading \"%s\"", obj->path); /* * Unlink the object now to prevent new references from * being acquired while the bind lock is dropped in * recursive dlclose() invocations. */ TAILQ_REMOVE(&obj_list, obj, next); obj_count--; if (obj->filtees_loaded) { if (next != NULL) { init_marker(&marker); TAILQ_INSERT_BEFORE(next, &marker, next); unload_filtees(obj, lockstate); next = TAILQ_NEXT(&marker, next); TAILQ_REMOVE(&obj_list, &marker, next); } else unload_filtees(obj, lockstate); } release_object(obj); } } static void unlink_object(Obj_Entry *root) { Objlist_Entry *elm; if (root->refcount == 0) { /* Remove the object from the RTLD_GLOBAL list. */ objlist_remove(&list_global, root); /* Remove the object from all objects' DAG lists. */ STAILQ_FOREACH(elm, &root->dagmembers, link) { objlist_remove(&elm->obj->dldags, root); if (elm->obj != root) unlink_object(elm->obj); } } } static void ref_dag(Obj_Entry *root) { Objlist_Entry *elm; assert(root->dag_inited); STAILQ_FOREACH(elm, &root->dagmembers, link) elm->obj->refcount++; } static void unref_dag(Obj_Entry *root) { Objlist_Entry *elm; assert(root->dag_inited); STAILQ_FOREACH(elm, &root->dagmembers, link) elm->obj->refcount--; } /* * Common code for MD __tls_get_addr(). */ static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; static void * tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) { Elf_Addr *newdtv, *dtv; RtldLockState lockstate; int to_copy; dtv = *dtvp; /* Check dtv generation in case new modules have arrived */ if (dtv[0] != tls_dtv_generation) { wlock_acquire(rtld_bind_lock, &lockstate); newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); to_copy = dtv[1]; if (to_copy > tls_max_index) to_copy = tls_max_index; memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); newdtv[0] = tls_dtv_generation; newdtv[1] = tls_max_index; free(dtv); lock_release(rtld_bind_lock, &lockstate); dtv = *dtvp = newdtv; } /* Dynamically allocate module TLS if necessary */ if (dtv[index + 1] == 0) { /* Signal safe, wlock will block out signals. */ wlock_acquire(rtld_bind_lock, &lockstate); if (!dtv[index + 1]) dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); lock_release(rtld_bind_lock, &lockstate); } return ((void *)(dtv[index + 1] + offset)); } void * tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) { Elf_Addr *dtv; dtv = *dtvp; /* Check dtv generation in case new modules have arrived */ if (__predict_true(dtv[0] == tls_dtv_generation && dtv[index + 1] != 0)) return ((void *)(dtv[index + 1] + offset)); return (tls_get_addr_slow(dtvp, index, offset)); } #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ defined(__powerpc__) || defined(__riscv) /* * Return pointer to allocated TLS block */ static void * get_tls_block_ptr(void *tcb, size_t tcbsize) { size_t extra_size, post_size, pre_size, tls_block_size; size_t tls_init_align; tls_init_align = MAX(obj_main->tlsalign, 1); /* Compute fragments sizes. */ extra_size = tcbsize - TLS_TCB_SIZE; post_size = calculate_tls_post_size(tls_init_align); tls_block_size = tcbsize + post_size; pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; return ((char *)tcb - pre_size - extra_size); } /* * Allocate Static TLS using the Variant I method. * * For details on the layout, see lib/libc/gen/tls.c. * * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as * it is based on tls_last_offset, and TLS offsets here are really TCB * offsets, whereas libc's tls_static_space is just the executable's static * TLS segment. */ void * allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) { Obj_Entry *obj; char *tls_block; Elf_Addr *dtv, **tcb; Elf_Addr addr; Elf_Addr i; size_t extra_size, maxalign, post_size, pre_size, tls_block_size; size_t tls_init_align, tls_init_offset; if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) return (oldtcb); assert(tcbsize >= TLS_TCB_SIZE); maxalign = MAX(tcbalign, tls_static_max_align); tls_init_align = MAX(obj_main->tlsalign, 1); /* Compute fragmets sizes. */ extra_size = tcbsize - TLS_TCB_SIZE; post_size = calculate_tls_post_size(tls_init_align); tls_block_size = tcbsize + post_size; pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; /* Allocate whole TLS block */ tls_block = malloc_aligned(tls_block_size, maxalign, 0); tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); if (oldtcb != NULL) { memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), tls_static_space); free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); /* Adjust the DTV. */ dtv = tcb[0]; for (i = 0; i < dtv[1]; i++) { if (dtv[i+2] >= (Elf_Addr)oldtcb && dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; } } } else { dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); tcb[0] = dtv; dtv[0] = tls_dtv_generation; dtv[1] = tls_max_index; for (obj = globallist_curr(objs); obj != NULL; obj = globallist_next(obj)) { if (obj->tlsoffset == 0) continue; tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); addr = (Elf_Addr)tcb + obj->tlsoffset; if (tls_init_offset > 0) memset((void *)addr, 0, tls_init_offset); if (obj->tlsinitsize > 0) { memcpy((void *)(addr + tls_init_offset), obj->tlsinit, obj->tlsinitsize); } if (obj->tlssize > obj->tlsinitsize) { memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); } dtv[obj->tlsindex + 1] = addr; } } return (tcb); } void free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) { Elf_Addr *dtv; Elf_Addr tlsstart, tlsend; size_t post_size; size_t dtvsize, i, tls_init_align; assert(tcbsize >= TLS_TCB_SIZE); tls_init_align = MAX(obj_main->tlsalign, 1); /* Compute fragments sizes. */ post_size = calculate_tls_post_size(tls_init_align); tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; tlsend = (Elf_Addr)tcb + tls_static_space; dtv = *(Elf_Addr **)tcb; dtvsize = dtv[1]; for (i = 0; i < dtvsize; i++) { if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { free((void*)dtv[i+2]); } } free(dtv); free_aligned(get_tls_block_ptr(tcb, tcbsize)); } #endif #if defined(__i386__) || defined(__amd64__) /* * Allocate Static TLS using the Variant II method. */ void * allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) { Obj_Entry *obj; size_t size, ralign; char *tls; Elf_Addr *dtv, *olddtv; Elf_Addr segbase, oldsegbase, addr; size_t i; ralign = tcbalign; if (tls_static_max_align > ralign) ralign = tls_static_max_align; size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); assert(tcbsize >= 2*sizeof(Elf_Addr)); tls = malloc_aligned(size, ralign, 0 /* XXX */); dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); ((Elf_Addr*)segbase)[0] = segbase; ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; dtv[0] = tls_dtv_generation; dtv[1] = tls_max_index; if (oldtls) { /* * Copy the static TLS block over whole. */ oldsegbase = (Elf_Addr) oldtls; memcpy((void *)(segbase - tls_static_space), (const void *)(oldsegbase - tls_static_space), tls_static_space); /* * If any dynamic TLS blocks have been created tls_get_addr(), * move them over. */ olddtv = ((Elf_Addr**)oldsegbase)[1]; for (i = 0; i < olddtv[1]; i++) { if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { dtv[i+2] = olddtv[i+2]; olddtv[i+2] = 0; } } /* * We assume that this block was the one we created with * allocate_initial_tls(). */ free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); } else { for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { if (obj->marker || obj->tlsoffset == 0) continue; addr = segbase - obj->tlsoffset; memset((void*)(addr + obj->tlsinitsize), 0, obj->tlssize - obj->tlsinitsize); if (obj->tlsinit) { memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); obj->static_tls_copied = true; } dtv[obj->tlsindex + 1] = addr; } } return (void*) segbase; } void free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) { Elf_Addr* dtv; size_t size, ralign; int dtvsize, i; Elf_Addr tlsstart, tlsend; /* * Figure out the size of the initial TLS block so that we can * find stuff which ___tls_get_addr() allocated dynamically. */ ralign = tcbalign; if (tls_static_max_align > ralign) ralign = tls_static_max_align; size = roundup(tls_static_space, ralign); dtv = ((Elf_Addr**)tls)[1]; dtvsize = dtv[1]; tlsend = (Elf_Addr) tls; tlsstart = tlsend - size; for (i = 0; i < dtvsize; i++) { if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { free_aligned((void *)dtv[i + 2]); } } free_aligned((void *)tlsstart); free((void*) dtv); } #endif /* * Allocate TLS block for module with given index. */ void * allocate_module_tls(int index) { Obj_Entry *obj; char *p; TAILQ_FOREACH(obj, &obj_list, next) { if (obj->marker) continue; if (obj->tlsindex == index) break; } if (obj == NULL) { _rtld_error("Can't find module with TLS index %d", index); rtld_die(); } p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); memcpy(p, obj->tlsinit, obj->tlsinitsize); memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); return (p); } bool allocate_tls_offset(Obj_Entry *obj) { size_t off; if (obj->tls_done) return true; if (obj->tlssize == 0) { obj->tls_done = true; return true; } if (tls_last_offset == 0) off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, obj->tlspoffset); else off = calculate_tls_offset(tls_last_offset, tls_last_size, obj->tlssize, obj->tlsalign, obj->tlspoffset); /* * If we have already fixed the size of the static TLS block, we * must stay within that size. When allocating the static TLS, we * leave a small amount of space spare to be used for dynamically * loading modules which use static TLS. */ if (tls_static_space != 0) { if (calculate_tls_end(off, obj->tlssize) > tls_static_space) return false; } else if (obj->tlsalign > tls_static_max_align) { tls_static_max_align = obj->tlsalign; } tls_last_offset = obj->tlsoffset = off; tls_last_size = obj->tlssize; obj->tls_done = true; return true; } void free_tls_offset(Obj_Entry *obj) { /* * If we were the last thing to allocate out of the static TLS * block, we give our space back to the 'allocator'. This is a * simplistic workaround to allow libGL.so.1 to be loaded and * unloaded multiple times. */ if (calculate_tls_end(obj->tlsoffset, obj->tlssize) == calculate_tls_end(tls_last_offset, tls_last_size)) { tls_last_offset -= obj->tlssize; tls_last_size = 0; } } void * _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) { void *ret; RtldLockState lockstate; wlock_acquire(rtld_bind_lock, &lockstate); ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, tcbsize, tcbalign); lock_release(rtld_bind_lock, &lockstate); return (ret); } void _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) { RtldLockState lockstate; wlock_acquire(rtld_bind_lock, &lockstate); free_tls(tcb, tcbsize, tcbalign); lock_release(rtld_bind_lock, &lockstate); } static void object_add_name(Obj_Entry *obj, const char *name) { Name_Entry *entry; size_t len; len = strlen(name); entry = malloc(sizeof(Name_Entry) + len); if (entry != NULL) { strcpy(entry->name, name); STAILQ_INSERT_TAIL(&obj->names, entry, link); } } static int object_match_name(const Obj_Entry *obj, const char *name) { Name_Entry *entry; STAILQ_FOREACH(entry, &obj->names, link) { if (strcmp(name, entry->name) == 0) return (1); } return (0); } static Obj_Entry * locate_dependency(const Obj_Entry *obj, const char *name) { const Objlist_Entry *entry; const Needed_Entry *needed; STAILQ_FOREACH(entry, &list_main, link) { if (object_match_name(entry->obj, name)) return entry->obj; } for (needed = obj->needed; needed != NULL; needed = needed->next) { if (strcmp(obj->strtab + needed->name, name) == 0 || (needed->obj != NULL && object_match_name(needed->obj, name))) { /* * If there is DT_NEEDED for the name we are looking for, * we are all set. Note that object might not be found if * dependency was not loaded yet, so the function can * return NULL here. This is expected and handled * properly by the caller. */ return (needed->obj); } } _rtld_error("%s: Unexpected inconsistency: dependency %s not found", obj->path, name); rtld_die(); } static int check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, const Elf_Vernaux *vna) { const Elf_Verdef *vd; const char *vername; vername = refobj->strtab + vna->vna_name; vd = depobj->verdef; if (vd == NULL) { _rtld_error("%s: version %s required by %s not defined", depobj->path, vername, refobj->path); return (-1); } for (;;) { if (vd->vd_version != VER_DEF_CURRENT) { _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", depobj->path, vd->vd_version); return (-1); } if (vna->vna_hash == vd->vd_hash) { const Elf_Verdaux *aux = (const Elf_Verdaux *) ((const char *)vd + vd->vd_aux); if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) return (0); } if (vd->vd_next == 0) break; vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); } if (vna->vna_flags & VER_FLG_WEAK) return (0); _rtld_error("%s: version %s required by %s not found", depobj->path, vername, refobj->path); return (-1); } static int rtld_verify_object_versions(Obj_Entry *obj) { const Elf_Verneed *vn; const Elf_Verdef *vd; const Elf_Verdaux *vda; const Elf_Vernaux *vna; const Obj_Entry *depobj; int maxvernum, vernum; if (obj->ver_checked) return (0); obj->ver_checked = true; maxvernum = 0; /* * Walk over defined and required version records and figure out * max index used by any of them. Do very basic sanity checking * while there. */ vn = obj->verneed; while (vn != NULL) { if (vn->vn_version != VER_NEED_CURRENT) { _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", obj->path, vn->vn_version); return (-1); } vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); for (;;) { vernum = VER_NEED_IDX(vna->vna_other); if (vernum > maxvernum) maxvernum = vernum; if (vna->vna_next == 0) break; vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); } if (vn->vn_next == 0) break; vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); } vd = obj->verdef; while (vd != NULL) { if (vd->vd_version != VER_DEF_CURRENT) { _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", obj->path, vd->vd_version); return (-1); } vernum = VER_DEF_IDX(vd->vd_ndx); if (vernum > maxvernum) maxvernum = vernum; if (vd->vd_next == 0) break; vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); } if (maxvernum == 0) return (0); /* * Store version information in array indexable by version index. * Verify that object version requirements are satisfied along the * way. */ obj->vernum = maxvernum + 1; obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); vd = obj->verdef; while (vd != NULL) { if ((vd->vd_flags & VER_FLG_BASE) == 0) { vernum = VER_DEF_IDX(vd->vd_ndx); assert(vernum <= maxvernum); vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); obj->vertab[vernum].hash = vd->vd_hash; obj->vertab[vernum].name = obj->strtab + vda->vda_name; obj->vertab[vernum].file = NULL; obj->vertab[vernum].flags = 0; } if (vd->vd_next == 0) break; vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); } vn = obj->verneed; while (vn != NULL) { depobj = locate_dependency(obj, obj->strtab + vn->vn_file); if (depobj == NULL) return (-1); vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); for (;;) { if (check_object_provided_version(obj, depobj, vna)) return (-1); vernum = VER_NEED_IDX(vna->vna_other); assert(vernum <= maxvernum); obj->vertab[vernum].hash = vna->vna_hash; obj->vertab[vernum].name = obj->strtab + vna->vna_name; obj->vertab[vernum].file = obj->strtab + vn->vn_file; obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? VER_INFO_HIDDEN : 0; if (vna->vna_next == 0) break; vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); } if (vn->vn_next == 0) break; vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); } return 0; } static int rtld_verify_versions(const Objlist *objlist) { Objlist_Entry *entry; int rc; rc = 0; STAILQ_FOREACH(entry, objlist, link) { /* * Skip dummy objects or objects that have their version requirements * already checked. */ if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) continue; if (rtld_verify_object_versions(entry->obj) == -1) { rc = -1; if (ld_tracing == NULL) break; } } if (rc == 0 || ld_tracing != NULL) rc = rtld_verify_object_versions(&obj_rtld); return rc; } const Ver_Entry * fetch_ventry(const Obj_Entry *obj, unsigned long symnum) { Elf_Versym vernum; if (obj->vertab) { vernum = VER_NDX(obj->versyms[symnum]); if (vernum >= obj->vernum) { _rtld_error("%s: symbol %s has wrong verneed value %d", obj->path, obj->strtab + symnum, vernum); } else if (obj->vertab[vernum].hash != 0) { return &obj->vertab[vernum]; } } return NULL; } int _rtld_get_stack_prot(void) { return (stack_prot); } int _rtld_is_dlopened(void *arg) { Obj_Entry *obj; RtldLockState lockstate; int res; rlock_acquire(rtld_bind_lock, &lockstate); obj = dlcheck(arg); if (obj == NULL) obj = obj_from_addr(arg); if (obj == NULL) { _rtld_error("No shared object contains address"); lock_release(rtld_bind_lock, &lockstate); return (-1); } res = obj->dlopened ? 1 : 0; lock_release(rtld_bind_lock, &lockstate); return (res); } static int obj_remap_relro(Obj_Entry *obj, int prot) { if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, prot) == -1) { _rtld_error("%s: Cannot set relro protection to %#x: %s", obj->path, prot, rtld_strerror(errno)); return (-1); } return (0); } static int obj_disable_relro(Obj_Entry *obj) { return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); } static int obj_enforce_relro(Obj_Entry *obj) { return (obj_remap_relro(obj, PROT_READ)); } static void map_stacks_exec(RtldLockState *lockstate) { void (*thr_map_stacks_exec)(void); if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) return; thr_map_stacks_exec = (void (*)(void))(uintptr_t) get_program_var_addr("__pthread_map_stacks_exec", lockstate); if (thr_map_stacks_exec != NULL) { stack_prot |= PROT_EXEC; thr_map_stacks_exec(); } } static void distribute_static_tls(Objlist *list, RtldLockState *lockstate) { Objlist_Entry *elm; Obj_Entry *obj; void (*distrib)(size_t, void *, size_t, size_t); distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) get_program_var_addr("__pthread_distribute_static_tls", lockstate); if (distrib == NULL) return; STAILQ_FOREACH(elm, list, link) { obj = elm->obj; if (obj->marker || !obj->tls_done || obj->static_tls_copied) continue; distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, obj->tlssize); obj->static_tls_copied = true; } } void symlook_init(SymLook *dst, const char *name) { bzero(dst, sizeof(*dst)); dst->name = name; dst->hash = elf_hash(name); dst->hash_gnu = gnu_hash(name); } static void symlook_init_from_req(SymLook *dst, const SymLook *src) { dst->name = src->name; dst->hash = src->hash; dst->hash_gnu = src->hash_gnu; dst->ventry = src->ventry; dst->flags = src->flags; dst->defobj_out = NULL; dst->sym_out = NULL; dst->lockstate = src->lockstate; } static int open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) { char *binpath, *pathenv, *pe, *res1; const char *res; int fd; binpath = NULL; res = NULL; if (search_in_path && strchr(argv0, '/') == NULL) { binpath = xmalloc(PATH_MAX); pathenv = getenv("PATH"); if (pathenv == NULL) { _rtld_error("-p and no PATH environment variable"); rtld_die(); } pathenv = strdup(pathenv); if (pathenv == NULL) { _rtld_error("Cannot allocate memory"); rtld_die(); } fd = -1; errno = ENOENT; while ((pe = strsep(&pathenv, ":")) != NULL) { if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) continue; if (binpath[0] != '\0' && strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) continue; if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) continue; fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); if (fd != -1 || errno != ENOENT) { res = binpath; break; } } free(pathenv); } else { fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); res = argv0; } if (fd == -1) { _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); rtld_die(); } if (res != NULL && res[0] != '/') { res1 = xmalloc(PATH_MAX); if (realpath(res, res1) != NULL) { if (res != argv0) free(__DECONST(char *, res)); res = res1; } else { free(res1); } } *binpath_res = res; return (fd); } /* * Parse a set of command-line arguments. */ static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, const char **argv0) { const char *arg; char machine[64]; size_t sz; int arglen, fd, i, j, mib[2]; char opt; bool seen_b, seen_f; dbg("Parsing command-line arguments"); *use_pathp = false; *fdp = -1; seen_b = seen_f = false; for (i = 1; i < argc; i++ ) { arg = argv[i]; dbg("argv[%d]: '%s'", i, arg); /* * rtld arguments end with an explicit "--" or with the first * non-prefixed argument. */ if (strcmp(arg, "--") == 0) { i++; break; } if (arg[0] != '-') break; /* * All other arguments are single-character options that can * be combined, so we need to search through `arg` for them. */ arglen = strlen(arg); for (j = 1; j < arglen; j++) { opt = arg[j]; if (opt == 'h') { print_usage(argv[0]); _exit(0); } else if (opt == 'b') { if (seen_f) { _rtld_error("Both -b and -f specified"); rtld_die(); } i++; *argv0 = argv[i]; seen_b = true; break; } else if (opt == 'f') { if (seen_b) { _rtld_error("Both -b and -f specified"); rtld_die(); } /* * -f XX can be used to specify a * descriptor for the binary named at * the command line (i.e., the later * argument will specify the process * name but the descriptor is what * will actually be executed). * * -f must be the last option in, e.g., -abcf. */ if (j != arglen - 1) { _rtld_error("Invalid options: %s", arg); rtld_die(); } i++; fd = parse_integer(argv[i]); if (fd == -1) { _rtld_error( "Invalid file descriptor: '%s'", argv[i]); rtld_die(); } *fdp = fd; seen_f = true; break; } else if (opt == 'p') { *use_pathp = true; } else if (opt == 'v') { machine[0] = '\0'; mib[0] = CTL_HW; mib[1] = HW_MACHINE; sz = sizeof(machine); sysctl(mib, nitems(mib), machine, &sz, NULL, 0); rtld_printf( "FreeBSD ld-elf.so.1 %s\n" "FreeBSD_version %d\n" "Default lib path %s\n" "Env prefix %s\n" "Hint file %s\n" "libmap file %s\n", machine, __FreeBSD_version, ld_standard_library_path, ld_env_prefix, ld_elf_hints_default, ld_path_libmap_conf); _exit(0); } else { _rtld_error("Invalid argument: '%s'", arg); print_usage(argv[0]); rtld_die(); } } } if (!seen_b) *argv0 = argv[i]; return (i); } /* * Parse a file descriptor number without pulling in more of libc (e.g. atoi). */ static int parse_integer(const char *str) { static const int RADIX = 10; /* XXXJA: possibly support hex? */ const char *orig; int n; char c; orig = str; n = 0; for (c = *str; c != '\0'; c = *++str) { if (c < '0' || c > '9') return (-1); n *= RADIX; n += c - '0'; } /* Make sure we actually parsed something. */ if (str == orig) return (-1); return (n); } static void print_usage(const char *argv0) { rtld_printf( "Usage: %s [-h] [-b ] [-f ] [-p] [--] []\n" "\n" "Options:\n" " -h Display this help message\n" " -b Execute instead of , arg0 is \n" " -f Execute instead of searching for \n" " -p Search in PATH for named binary\n" " -v Display identification information\n" " -- End of RTLD options\n" " Name of process to execute\n" " Arguments to the executed process\n", argv0); } /* * Overrides for libc_pic-provided functions. */ int __getosreldate(void) { size_t len; int oid[2]; int error, osrel; if (osreldate != 0) return (osreldate); oid[0] = CTL_KERN; oid[1] = KERN_OSRELDATE; osrel = 0; len = sizeof(osrel); error = sysctl(oid, 2, &osrel, &len, NULL, 0); if (error == 0 && osrel > 0 && len == sizeof(osrel)) osreldate = osrel; return (osreldate); } const char * rtld_strerror(int errnum) { if (errnum < 0 || errnum >= sys_nerr) return ("Unknown error"); return (sys_errlist[errnum]); } /* malloc */ void * malloc(size_t nbytes) { return (__crt_malloc(nbytes)); } void * calloc(size_t num, size_t size) { return (__crt_calloc(num, size)); } void free(void *cp) { __crt_free(cp); } void * realloc(void *cp, size_t nbytes) { return (__crt_realloc(cp, nbytes)); } extern int _rtld_version__FreeBSD_version __exported; int _rtld_version__FreeBSD_version = __FreeBSD_version; extern char _rtld_version_laddr_offset __exported; char _rtld_version_laddr_offset; + +extern char _rtld_version_dlpi_tls_data __exported; +char _rtld_version_dlpi_tls_data; diff --git a/sys/sys/param.h b/sys/sys/param.h index 5176dd1e9732..e3230de27bb1 100644 --- a/sys/sys/param.h +++ b/sys/sys/param.h @@ -1,375 +1,375 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)param.h 8.3 (Berkeley) 4/4/95 * $FreeBSD$ */ #ifndef _SYS_PARAM_H_ #define _SYS_PARAM_H_ #include #define BSD 199506 /* System version (year & month). */ #define BSD4_3 1 #define BSD4_4 1 /* * __FreeBSD_version numbers are documented in the Porter's Handbook. * If you bump the version for any reason, you should update the documentation * there. * Currently this lives here in the doc/ repository: * * documentation/content/en/books/porters-handbook/versions/chapter.adoc * * scheme is: Rxx * 'R' is in the range 0 to 4 if this is a release branch or * X.0-CURRENT before releng/X.0 is created, otherwise 'R' is * in the range 5 to 9. */ #undef __FreeBSD_version -#define __FreeBSD_version 1400006 /* Master, propagated to newvers */ +#define __FreeBSD_version 1400007 /* Master, propagated to newvers */ /* * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD, * which by definition is always true on FreeBSD. This macro is also defined * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD. * * It is tempting to use this macro in userland code when we want to enable * kernel-specific routines, and in fact it's fine to do this in code that * is part of FreeBSD itself. However, be aware that as presence of this * macro is still not widespread (e.g. older FreeBSD versions, 3rd party * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in * external applications without also checking for __FreeBSD__ as an * alternative. */ #undef __FreeBSD_kernel__ #define __FreeBSD_kernel__ #if defined(_KERNEL) || defined(IN_RTLD) #define P_OSREL_SIGWAIT 700000 #define P_OSREL_SIGSEGV 700004 #define P_OSREL_MAP_ANON 800104 #define P_OSREL_MAP_FSTRICT 1100036 #define P_OSREL_SHUTDOWN_ENOTCONN 1100077 #define P_OSREL_MAP_GUARD 1200035 #define P_OSREL_WRFSBASE 1200041 #define P_OSREL_CK_CYLGRP 1200046 #define P_OSREL_VMTOTAL64 1200054 #define P_OSREL_CK_SUPERBLOCK 1300000 #define P_OSREL_CK_INODE 1300005 #define P_OSREL_POWERPC_NEW_AUX_ARGS 1300070 #define P_OSREL_MAJOR(x) ((x) / 100000) #endif #ifndef LOCORE #include #endif /* * Machine-independent constants (some used in following include files). * Redefined constants are from POSIX 1003.1 limits file. * * MAXCOMLEN should be >= sizeof(ac_comm) (see ) */ #include #define MAXCOMLEN 19 /* max command name remembered */ #define MAXINTERP PATH_MAX /* max interpreter file name length */ #define MAXLOGNAME 33 /* max login name length (incl. NUL) */ #define MAXUPRC CHILD_MAX /* max simultaneous processes */ #define NCARGS ARG_MAX /* max bytes for an exec function */ #define NGROUPS (NGROUPS_MAX+1) /* max number groups */ #define NOFILE OPEN_MAX /* max open files per process */ #define NOGROUP 65535 /* marker for empty group set member */ #define MAXHOSTNAMELEN 256 /* max hostname size */ #define SPECNAMELEN 255 /* max length of devicename */ /* More types and definitions used throughout the kernel. */ #ifdef _KERNEL #include #include #ifndef LOCORE #include #include #endif #ifndef FALSE #define FALSE 0 #endif #ifndef TRUE #define TRUE 1 #endif #endif #ifndef _KERNEL #ifndef LOCORE /* Signals. */ #include #endif #endif /* Machine type dependent parameters. */ #include #ifndef _KERNEL #include #endif #ifndef DEV_BSHIFT #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ #endif #define DEV_BSIZE (1<>PAGE_SHIFT) #endif /* * btodb() is messy and perhaps slow because `bytes' may be an off_t. We * want to shift an unsigned type to avoid sign extension and we don't * want to widen `bytes' unnecessarily. Assume that the result fits in * a daddr_t. */ #ifndef btodb #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ (sizeof (bytes) > sizeof(long) \ ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) #endif #ifndef dbtob #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ ((off_t)(db) << DEV_BSHIFT) #endif #define PRIMASK 0x0ff #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ #define PRILASTFLAG 0x200 /* Last flag defined above */ #define NZERO 0 /* default "nice" */ #define NBBY 8 /* number of bits in a byte */ #define NBPW sizeof(int) /* number of bytes per word (integer) */ #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ #define NODEV (dev_t)(-1) /* non-existent device */ /* * File system parameters and macros. * * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes * per block. MAXBSIZE may be made larger without effecting * any existing filesystems as long as it does not exceed MAXPHYS, * and may be made smaller at the risk of not being able to use * filesystems which require a block size exceeding MAXBSIZE. * * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must * be >= MAXBSIZE and can be set differently for different * architectures by defining it in . * Making this larger allows NFS to do larger reads/writes. * * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the * minimum KVM memory reservation the kernel is willing to make. * Filesystems can of course request smaller chunks. Actual * backing memory uses a chunk size of a page (PAGE_SIZE). * The default value here can be overridden on a per-architecture * basis by defining it in . * * If you make BKVASIZE too small you risk seriously fragmenting * the buffer KVM map which may slow things down a bit. If you * make it too big the kernel will not be able to optimally use * the KVM memory reserved for the buffer cache and will wind * up with too-few buffers. * * The default is 16384, roughly 2x the block size used by a * normal UFS filesystem. */ #define MAXBSIZE 65536 /* must be power of 2 */ #ifndef MAXBCACHEBUF #define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */ #endif #ifndef BKVASIZE #define BKVASIZE 16384 /* must be power of 2 */ #endif #define BKVAMASK (BKVASIZE-1) /* * MAXPATHLEN defines the longest permissible path length after expanding * symbolic links. It is used to allocate a temporary buffer from the buffer * pool in which to do the name expansion, hence should be a power of two, * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the * maximum number of symbolic links that may be expanded in a path name. * It should be set high enough to allow all legitimate uses, but halt * infinite loops reasonably quickly. */ #define MAXPATHLEN PATH_MAX #define MAXSYMLINKS 32 /* Bit map related macros. */ #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) #define isset(a,i) \ (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) #define isclr(a,i) \ ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) /* Macros for counting and rounding. */ #ifndef howmany #define howmany(x, y) (((x)+((y)-1))/(y)) #endif #define nitems(x) (sizeof((x)) / sizeof((x)[0])) #define rounddown(x, y) (((x)/(y))*(y)) #define rounddown2(x, y) __align_down(x, y) /* if y is power of two */ #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ #define roundup2(x, y) __align_up(x, y) /* if y is powers of two */ #define powerof2(x) ((((x)-1)&(x))==0) /* Macros for min/max. */ #define MIN(a,b) (((a)<(b))?(a):(b)) #define MAX(a,b) (((a)>(b))?(a):(b)) #ifdef _KERNEL /* * Basic byte order function prototypes for non-inline functions. */ #ifndef LOCORE #ifndef _BYTEORDER_PROTOTYPED #define _BYTEORDER_PROTOTYPED __BEGIN_DECLS __uint32_t htonl(__uint32_t); __uint16_t htons(__uint16_t); __uint32_t ntohl(__uint32_t); __uint16_t ntohs(__uint16_t); __END_DECLS #endif #endif #ifndef _BYTEORDER_FUNC_DEFINED #define _BYTEORDER_FUNC_DEFINED #define htonl(x) __htonl(x) #define htons(x) __htons(x) #define ntohl(x) __ntohl(x) #define ntohs(x) __ntohs(x) #endif /* !_BYTEORDER_FUNC_DEFINED */ #endif /* _KERNEL */ /* * Scale factor for scaled integers used to count %cpu time and load avgs. * * The number of CPU `tick's that map to a unique `%age' can be expressed * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that * can be calculated (assuming 32 bits) can be closely approximated using * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). * * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. */ #define FSHIFT 11 /* bits to right of fixed binary point */ #define FSCALE (1<> (PAGE_SHIFT - DEV_BSHIFT)) #define ctodb(db) /* calculates pages to devblks */ \ ((db) << (PAGE_SHIFT - DEV_BSHIFT)) /* * Old spelling of __containerof(). */ #define member2struct(s, m, x) \ ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) /* * Access a variable length array that has been declared as a fixed * length array. */ #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) #endif /* _SYS_PARAM_H_ */