diff --git a/libexec/rtld-elf/map_object.c b/libexec/rtld-elf/map_object.c --- a/libexec/rtld-elf/map_object.c +++ b/libexec/rtld-elf/map_object.c @@ -345,6 +345,39 @@ return (NULL); } +bool +check_elf_headers(const Elf_Ehdr *hdr, const char *path) +{ + if (!IS_ELF(*hdr)) { + _rtld_error("%s: invalid file format", path); + return (false); + } + if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || + hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { + _rtld_error("%s: unsupported file layout", path); + return (false); + } + if (hdr->e_ident[EI_VERSION] != EV_CURRENT || + hdr->e_version != EV_CURRENT) { + _rtld_error("%s: unsupported file version", path); + return (false); + } + if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { + _rtld_error("%s: unsupported file type", path); + return (false); + } + if (hdr->e_machine != ELF_TARG_MACH) { + _rtld_error("%s: unsupported machine", path); + return (false); + } + if (hdr->e_phentsize != sizeof(Elf_Phdr)) { + _rtld_error( + "%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path); + return (false); + } + return (true); +} + static Elf_Ehdr * get_elf_header(int fd, const char *path, const struct stat *sbp, Elf_Phdr **phdr_p) @@ -366,39 +399,14 @@ } /* Make sure the file is valid */ - if (!IS_ELF(*hdr)) { - _rtld_error("%s: invalid file format", path); + if (!check_elf_headers(hdr, path)) goto error; - } - if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || - hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { - _rtld_error("%s: unsupported file layout", path); - goto error; - } - if (hdr->e_ident[EI_VERSION] != EV_CURRENT || - hdr->e_version != EV_CURRENT) { - _rtld_error("%s: unsupported file version", path); - goto error; - } - if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { - _rtld_error("%s: unsupported file type", path); - goto error; - } - if (hdr->e_machine != ELF_TARG_MACH) { - _rtld_error("%s: unsupported machine", path); - goto error; - } /* * We rely on the program header being in the first page. This is * not strictly required by the ABI specification, but it seems to * always true in practice. And, it simplifies things considerably. */ - if (hdr->e_phentsize != sizeof(Elf_Phdr)) { - _rtld_error( - "%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path); - goto error; - } if (phdr_in_zero_page(hdr)) { phdr = (Elf_Phdr *)((char *)hdr + hdr->e_phoff); } else { diff --git a/libexec/rtld-elf/rtld.h b/libexec/rtld-elf/rtld.h --- a/libexec/rtld-elf/rtld.h +++ b/libexec/rtld-elf/rtld.h @@ -405,6 +405,7 @@ const Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); int convert_prot(int elfflags); void *_get_tp(void); /* libc implementation */ +bool check_elf_headers(const Elf_Ehdr *hdr, const char *path); /* * MD function declarations. diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c --- a/libexec/rtld-elf/rtld.c +++ b/libexec/rtld-elf/rtld.c @@ -124,6 +124,7 @@ static void unload_filtees(Obj_Entry *, RtldLockState *); static int load_needed_objects(Obj_Entry *, int); static int load_preload_objects(const char *, bool); +static int load_kpreload(const void *addr); 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 *); @@ -825,6 +826,12 @@ if (!libmap_disable) libmap_disable = (bool)lm_init(libmap_override); + if (aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { + dbg("loading kernel vdso"); + if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) + rtld_die(); + } + dbg("loading LD_PRELOAD_FDS libraries"); if (load_preload_objects(ld_preload_fds, true) == -1) rtld_die(); @@ -2836,6 +2843,73 @@ return (NULL); } +static int +load_kpreload(const void *addr) +{ + Obj_Entry *obj; + const Elf_Ehdr *ehdr; + const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; + Elf_Addr phdr_vaddr; + size_t phsize; + static const char kname[] = "[vdso]"; + + ehdr = addr; + if (!check_elf_headers(ehdr, "kpreload")) + return (false); + phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); + phlimit = phdr + ehdr->e_phnum; + phdr_vaddr = (Elf_Addr)phdr; + phsize = ehdr->e_phnum * sizeof(*phdr); + seg0 = segn = NULL; + obj = obj_new(); + + for (; phdr < phlimit; phdr++) { + switch (phdr->p_type) { + case PT_DYNAMIC: + phdyn = phdr; + break; + case PT_GNU_STACK: + obj->stack_flags = phdr->p_flags; + break; + case PT_LOAD: + if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) + seg0 = phdr; + if (segn == NULL || segn->p_vaddr + segn->p_memsz < + phdr->p_vaddr + phdr->p_memsz) + segn = phdr; + break; + } + } + + obj->mapbase = __DECONST(caddr_t, addr); + obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; + obj->vaddrbase = 0; + obj->relocbase = obj->mapbase; + + object_add_name(obj, kname); + obj->path = xstrdup(kname); + obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); + obj->phdr = (const Elf_Phdr *)(obj->relocbase + phdr_vaddr); + obj->phsize = phsize; + + if (!digest_dynamic(obj, 0)) { + obj_free(obj); + return (-1); + } + + dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, + obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); + + TAILQ_INSERT_TAIL(&obj_list, obj, next); + obj_count++; + obj_loads++; + linkmap_add(obj); /* for GDB & dlinfo() */ + max_stack_flags |= obj->stack_flags; + + LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); + return (0); +} + Obj_Entry * obj_from_addr(const void *addr) { diff --git a/sys/amd64/amd64/elf_machdep.c b/sys/amd64/amd64/elf_machdep.c --- a/sys/amd64/amd64/elf_machdep.c +++ b/sys/amd64/amd64/elf_machdep.c @@ -49,14 +49,21 @@ #include #include +#include "vdso_offsets.h" + +extern const char _binary_elf_vdso_so_1_start[]; +extern const char _binary_elf_vdso_so_1_end[]; +extern char _binary_elf_vdso_so_1_size; + struct sysentvec elf64_freebsd_sysvec_la48 = { .sv_size = SYS_MAXSYSCALL, .sv_table = sysent, .sv_transtrap = NULL, .sv_fixup = __elfN(freebsd_fixup), .sv_sendsig = sendsig, - .sv_sigcode = sigcode, - .sv_szsigcode = &szsigcode, + .sv_sigcode = _binary_elf_vdso_so_1_start, + .sv_szsigcode = (int *)&_binary_elf_vdso_so_1_size, + .sv_sigcodeoff = VDSO_SIGCODE_OFFSET, .sv_name = "FreeBSD ELF64", .sv_coredump = __elfN(coredump), .sv_elf_core_osabi = ELFOSABI_FREEBSD, @@ -75,7 +82,7 @@ .sv_fixlimit = NULL, .sv_maxssiz = NULL, .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP | - SV_TIMEKEEP | SV_RNG_SEED_VER, + SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG, .sv_set_syscall_retval = cpu_set_syscall_retval, .sv_fetch_syscall_args = cpu_fetch_syscall_args, .sv_syscallnames = syscallnames, @@ -96,8 +103,9 @@ .sv_transtrap = NULL, .sv_fixup = __elfN(freebsd_fixup), .sv_sendsig = sendsig, - .sv_sigcode = sigcode, - .sv_szsigcode = &szsigcode, + .sv_sigcode = _binary_elf_vdso_so_1_start, + .sv_szsigcode = (int *)&_binary_elf_vdso_so_1_size, + .sv_sigcodeoff = VDSO_SIGCODE_OFFSET, .sv_name = "FreeBSD ELF64", .sv_coredump = __elfN(coredump), .sv_elf_core_osabi = ELFOSABI_FREEBSD, @@ -116,7 +124,7 @@ .sv_fixlimit = NULL, .sv_maxssiz = NULL, .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP | - SV_TIMEKEEP | SV_RNG_SEED_VER, + SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG, .sv_set_syscall_retval = cpu_set_syscall_retval, .sv_fetch_syscall_args = cpu_fetch_syscall_args, .sv_syscallnames = syscallnames, diff --git a/sys/amd64/amd64/sigtramp.S b/sys/amd64/amd64/sigtramp.S --- a/sys/amd64/amd64/sigtramp.S +++ b/sys/amd64/amd64/sigtramp.S @@ -38,7 +38,7 @@ * Signal trampoline, copied to top of user stack * */ -ENTRY(sigcode) +ENTRY(__vdso_sigcode) call *SIGF_HANDLER(%rsp) /* call signal handler */ lea SIGF_UC(%rsp),%rdi /* get ucontext_t */ pushq $0 /* junk to fake return addr. */ @@ -46,11 +46,6 @@ syscall /* enter kernel with args */ 0: hlt /* trap priviliged instruction */ jmp 0b +END(__vdso_sigcode) - ALIGN_TEXT -esigcode: - - .data - .globl szsigcode -szsigcode: - .long esigcode-sigcode + .section .note.GNU-stack,"",%progbits diff --git a/sys/amd64/amd64/vdso.ldscript b/sys/amd64/amd64/vdso.ldscript new file mode 100644 --- /dev/null +++ b/sys/amd64/amd64/vdso.ldscript @@ -0,0 +1,59 @@ +/* + * Linker script for amd64 vdso. + */ + +PHDRS +{ + text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(5); + eh_frame_hdr PT_GNU_EH_FRAME FLAGS(5); +} + +SECTIONS +{ + . = . + SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } :text + .dynsym : { *(.dynsym) } :text + .dynstr : { *(.dynstr) } :text + .gnu.version : { *(.gnu.version) } :text + .gnu.version_d : { *(.gnu.version_d) } :text + .gnu.version_r : { *(.gnu.version_r) } :text + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + .dynamic : { *(.dynamic) } :text :dynamic + .rodata : { *(.rodata*) } :text + .data : { + *(.got.plt) *(.got) + } :text + /DISCARD/ /* .data */: { + *(.data*) + *(.sdata*) + *(.gnu.linkonce.d.*) + *(.bss*) + *(.dynbss*) + *(.gnu.linkonce.b.*) + *(.ctors) + *(.dtors) + *(.jcr) + *(.init_array) + *(.init) + *(.fini) + *(.debug*) + *(.comment) + } + + . = ALIGN(0x10); + .text : { *(.test .text*) } :text =0x90909090 +} + +VERSION +{ + FBSD_1.7 { + global: + __vdso_sigcode; + local: + *; + }; +} diff --git a/sys/conf/files.amd64 b/sys/conf/files.amd64 --- a/sys/conf/files.amd64 +++ b/sys/conf/files.amd64 @@ -12,6 +12,12 @@ # dependency lines other than the first are silently ignored. # # +elf-vdso.so.o standard \ + dependency "$S/amd64/amd64/sigtramp.S assym.inc $S/tools/amd64_vdso.sh" \ + compile-with "env NM='${NM}' LD='${LD}' CC='${CC}' OBJCOPY='${OBJCOPY}' S='${S}' sh $S/tools/amd64_vdso.sh" \ + no-implicit-rule before-depend \ + clean "elf-vdso.so.o elf-vdso.so.1 vdso_offset.h sigtramp.pico" +# ia32_genassym.o standard \ dependency "$S/compat/ia32/ia32_genassym.c offset.inc" \ compile-with "${CC} ${CFLAGS:N-flto:N-fno-common} -fcommon -c ${.IMPSRC}" \ @@ -76,7 +82,6 @@ amd64/amd64/mpboot.S optional smp amd64/amd64/pmap.c standard amd64/amd64/ptrace_machdep.c standard -amd64/amd64/sigtramp.S standard amd64/amd64/support.S standard amd64/amd64/sys_machdep.c standard amd64/amd64/trap.c standard diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c --- a/sys/kern/imgact_elf.c +++ b/sys/kern/imgact_elf.c @@ -1400,6 +1400,8 @@ AUXARGS_ENTRY_PTR(pos, AT_PS_STRINGS, imgp->ps_strings); if (imgp->sysent->sv_fxrng_gen_base != 0) AUXARGS_ENTRY(pos, AT_FXRNG, imgp->sysent->sv_fxrng_gen_base); + if (imgp->sysent->sv_vdso_base != 0) + AUXARGS_ENTRY(pos, AT_KPRELOAD, imgp->sysent->sv_vdso_base); AUXARGS_ENTRY(pos, AT_NULL, 0); free(imgp->auxargs, M_TEMP); diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c --- a/sys/kern/kern_proc.c +++ b/sys/kern/kern_proc.c @@ -3100,7 +3100,9 @@ if (sv->sv_sigcode_base != 0) { kst32.ksigtramp_start = sv->sv_sigcode_base; kst32.ksigtramp_end = sv->sv_sigcode_base + - *sv->sv_szsigcode; + ((sv->sv_flags & SV_DSO_SIG) == 0 ? + *sv->sv_szsigcode : + (uintptr_t)sv->sv_szsigcode); } else { kst32.ksigtramp_start = sv->sv_psstrings - *sv->sv_szsigcode; @@ -3116,7 +3118,8 @@ if (sv->sv_sigcode_base != 0) { kst.ksigtramp_start = (char *)sv->sv_sigcode_base; kst.ksigtramp_end = (char *)sv->sv_sigcode_base + - *sv->sv_szsigcode; + ((sv->sv_flags & SV_DSO_SIG) == 0 ? *sv->sv_szsigcode : + (uintptr_t)sv->sv_szsigcode); } else { kst.ksigtramp_start = (char *)sv->sv_psstrings - *sv->sv_szsigcode; diff --git a/sys/kern/kern_sharedpage.c b/sys/kern/kern_sharedpage.c --- a/sys/kern/kern_sharedpage.c +++ b/sys/kern/kern_sharedpage.c @@ -305,10 +305,12 @@ exec_sysvec_init(void *param) { struct sysentvec *sv; + vm_offset_t sb; #ifdef RANDOM_FENESTRASX ptrdiff_t base; #endif u_int flags; + int res; sv = param; flags = sv->sv_flags; @@ -319,8 +321,21 @@ sv->sv_shared_page_obj = shared_page_obj; if ((flags & SV_ABI_MASK) == SV_ABI_FREEBSD) { - sv->sv_sigcode_base = sv->sv_shared_page_base + - shared_page_fill(*(sv->sv_szsigcode), 16, sv->sv_sigcode); + if ((flags & SV_DSO_SIG) != 0) { + sb = sv->sv_shared_page_base; + res = shared_page_fill((uintptr_t)sv->sv_szsigcode, + 16, sv->sv_sigcode); + if (res == -1) + panic("copying sigtramp to shared page"); + sb += res; + sv->sv_vdso_base = sb; + sb += sv->sv_sigcodeoff; + sv->sv_sigcode_base = sb; + } else { + sv->sv_sigcode_base = sv->sv_shared_page_base + + shared_page_fill(*(sv->sv_szsigcode), 16, + sv->sv_sigcode); + } } if ((flags & SV_TIMEKEEP) != 0) { #ifdef COMPAT_FREEBSD32 @@ -372,12 +387,18 @@ MPASS((sv2->sv_flags & SV_ABI_MASK) == (sv->sv_flags & SV_ABI_MASK)); MPASS((sv2->sv_flags & SV_TIMEKEEP) == (sv->sv_flags & SV_TIMEKEEP)); MPASS((sv2->sv_flags & SV_SHP) != 0 && (sv->sv_flags & SV_SHP) != 0); + MPASS((sv2->sv_flags & SV_DSO_SIG) != 0 && + (sv->sv_flags & SV_DSO_SIG) != 0); MPASS((sv2->sv_flags & SV_RNG_SEED_VER) == (sv->sv_flags & SV_RNG_SEED_VER)); sv2->sv_shared_page_obj = sv->sv_shared_page_obj; sv2->sv_sigcode_base = sv2->sv_shared_page_base + (sv->sv_sigcode_base - sv->sv_shared_page_base); + if ((sv2->sv_flags & SV_DSO_SIG) != 0) { + sv2->sv_vdso_base = sv2->sv_shared_page_base + + (sv->sv_vdso_base - sv->sv_shared_page_base); + } if ((sv2->sv_flags & SV_ABI_MASK) != SV_ABI_FREEBSD) return; if ((sv2->sv_flags & SV_TIMEKEEP) != 0) { diff --git a/sys/sys/elf_common.h b/sys/sys/elf_common.h --- a/sys/sys/elf_common.h +++ b/sys/sys/elf_common.h @@ -981,8 +981,9 @@ #define AT_ENVV 31 /* Environment vector */ #define AT_PS_STRINGS 32 /* struct ps_strings */ #define AT_FXRNG 33 /* Pointer to root RNG seed version. */ +#define AT_KPRELOAD 34 -#define AT_COUNT 34 /* Count of defined aux entry types. */ +#define AT_COUNT 35 /* Count of defined aux entry types. */ /* * Relocation types. diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h --- a/sys/sys/sysent.h +++ b/sys/sys/sysent.h @@ -109,8 +109,9 @@ /* stack fixup function */ void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *); /* send signal */ - char *sv_sigcode; /* start of sigtramp code */ + const char *sv_sigcode; /* start of sigtramp code */ int *sv_szsigcode; /* size of sigtramp code */ + int sv_sigcodeoff; char *sv_name; /* name of binary type */ int (*sv_coredump)(struct thread *, struct vnode *, off_t, int); /* function to dump core, or NULL */ @@ -143,6 +144,7 @@ vm_offset_t sv_shared_page_len; vm_offset_t sv_sigcode_base; void *sv_shared_page_obj; + vm_offset_t sv_vdso_base; void (*sv_schedtail)(struct thread *); void (*sv_thread_detach)(struct thread *); int (*sv_trap)(struct thread *); @@ -171,6 +173,7 @@ #define SV_RNG_SEED_VER 0x100000 /* random(4) reseed generation. */ #define SV_SIG_DISCIGN 0x200000 /* Do not discard ignored signals */ #define SV_SIG_WAITNDQ 0x400000 /* Wait does not dequeue SIGCHLD */ +#define SV_DSO_SIG 0x800000 /* Signal trampoline packed in dso */ #define SV_ABI_MASK 0xff #define SV_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x)) diff --git a/sys/tools/amd64_vdso.sh b/sys/tools/amd64_vdso.sh new file mode 100644 --- /dev/null +++ b/sys/tools/amd64_vdso.sh @@ -0,0 +1,15 @@ +#!/bin/sh +set -e +${CC} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \ + -o sigtramp.pico -I. -I${S} \ + ${S}/amd64/amd64/sigtramp.S +${LD} --shared -Bsymbolic -soname="elf-vdso.so.1" \ + --eh-frame-hdr --no-undefined -z rodynamic -z norelro -nmagic \ + --hash-style=sysv --fatal-warnings --strip-all \ + -o elf-vdso.so.1 sigtramp.pico +${OBJCOPY} --input-target binary \ + --output-target elf64-x86-64 --binary-architecture i386:x86-64 \ + elf-vdso.so.1 elf-vdso.so.o +${NM} -D elf-vdso.so.1 | \ + awk '/__vdso_sigcode/{printf "#define VDSO_SIGCODE_OFFSET 0x%s\n",$1}' \ + >vdso_offsets.h