diff --git a/share/man/man5/core.5 b/share/man/man5/core.5 index d176548d1570..0af1b2b7e8bf 100644 --- a/share/man/man5/core.5 +++ b/share/man/man5/core.5 @@ -1,176 +1,190 @@ .\" Copyright (c) 1980, 1991, 1993 .\" The Regents of the University of California. 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. 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. .\" .\" @(#)core.5 8.3 (Berkeley) 12/11/93 .\" $FreeBSD$ .\" -.Dd August 2, 2020 +.Dd October 5, 2021 .Dt CORE 5 .Os .Sh NAME .Nm core .Nd memory image file format .Sh SYNOPSIS .In sys/param.h .Sh DESCRIPTION A small number of signals which cause abnormal termination of a process also cause a record of the process's in-core state to be written to disk for later examination by one of the available debuggers. (See .Xr sigaction 2 . ) This memory image is written to a file named by default .Nm programname.core in the working directory; provided the terminated process had write permission in the directory, and provided the abnormality did not cause a system crash. (In this event, the decision to save the core file is arbitrary, see .Xr savecore 8 . ) .Pp The maximum size of a core file is limited by the .Dv RLIMIT_CORE .Xr setrlimit 2 limit. Files which would be larger than the limit are not created. .Pp +With a large limit, a process that had mapped a very large, +and perhaps sparsely populated, virtual memory region, could take +a very long time to create core dumps. +The system ignores all signals sent to a process writing a core file, except +.Dv SIGKILL +which terminates the writing and causes immediate exit of the process. +The behavior of +.Dv SIGKILL +can be disabled by setting tunable +.Xr sysctl 8 +variable +.Va kern.core_dump_can_intr +to zero. +.Pp The name of the file is controlled via the .Xr sysctl 8 variable .Va kern.corefile . The contents of this variable describes a filename to store the core image to. This filename can be absolute, or relative (which will resolve to the current working directory of the program generating it). .Pp The following format specifiers may be used in the .Va kern.corefile sysctl to insert additional information into the resulting core filename: .Bl -tag -width "1234567890" -compact -offset "12345" .It Em \&%H Machine hostname. .It Em \&%I An index starting at zero until the sysctl .Em debug.ncores is reached. This can be useful for limiting the number of corefiles generated by a particular process. .It Em \&%N process name. .It Em \&%P processes PID. .It Em \&%S signal during core. .It Em \&%U process UID. .El .Pp The name defaults to .Em \&%N.core , yielding the traditional .Fx behaviour. .Pp By default, a process that changes user or group credentials whether real or effective will not create a corefile. This behaviour can be changed to generate a core dump by setting the .Xr sysctl 8 variable .Va kern.sugid_coredump to 1. .Pp Corefiles can be compressed by the kernel if the following item is included in the kernel configuration file: .Bl -tag -width "1234567890" -compact -offset "12345" .It options GZIO .El .Pp The following sysctl control core file compression: .Bl -tag -width "kern.compress_user_cores_level" -compact -offset "12345" .It Em kern.compress_user_cores Enable compression of user cores. A value of 1 configures .Xr gzip 1 compression, and a value of 2 configures .Xr zstd 1 compression. Compressed core files will have a suffix of .Ql .gz or .Ql .zst appended to their filenames depending on the selected format. .It Em kern.compress_user_cores_level Compression level. Defaults to 6. .El .Sh NOTES Corefiles are written with open file descriptor information as an ELF note. By default, file paths are packed to only use as much space as needed. However, file paths can change at any time, including during core dump, and this can result in truncated file descriptor data. .Pp All file descriptor information can be preserved by disabling packing. This potentially wastes up to PATH_MAX bytes per open fd. Packing is disabled with .Dl sysctl kern.coredump_pack_fileinfo=0 . .Pp Similarly, corefiles are written with vmmap information as an ELF note, which contains file paths. By default, they are packed to only use as much space as needed. By the same mechanism as for the open files note, these paths can also change at any time and result in a truncated note. .Pp All vmmap information can be preserved by disabling packing. Like the file information, this potentially wastes up to PATH_MAX bytes per mapped object. Packing is disabled with .Dl sysctl kern.coredump_pack_vmmapinfo=0 . .Sh EXAMPLES In order to store all core images in per-user private areas under .Pa /var/coredumps , the following .Xr sysctl 8 command can be used: .Pp .Dl sysctl kern.corefile=/var/coredumps/\&%U/\&%N.core .Sh SEE ALSO .Xr gdb 1 , .Xr gzip 1 , .Xr kgdb 1 , .Xr setrlimit 2 , .Xr sigaction 2 , .Xr sysctl 8 .Sh HISTORY A .Nm file format appeared in .At v1 . diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c index 057c583324bb..e1b6e3fc6ba7 100644 --- a/sys/kern/imgact_elf.c +++ b/sys/kern/imgact_elf.c @@ -1,2858 +1,2862 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 2017 Dell EMC * Copyright (c) 2000-2001, 2003 David O'Brien * Copyright (c) 1995-1996 Søren Schmidt * Copyright (c) 1996 Peter Wemm * 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 * in this position and unchanged. * 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. 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. */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ELF_NOTE_ROUNDSIZE 4 #define OLD_EI_BRAND 8 static int __elfN(check_header)(const Elf_Ehdr *hdr); static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp, const char *interp, int32_t *osrel, uint32_t *fctl0); static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr, u_long *entry); static int __elfN(load_section)(struct image_params *imgp, vm_ooffset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot); static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp); static bool __elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel); static bool kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel); static boolean_t __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote, int32_t *osrel, boolean_t *has_fctl0, uint32_t *fctl0); static vm_prot_t __elfN(trans_prot)(Elf_Word); static Elf_Word __elfN(untrans_prot)(vm_prot_t); SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW | CTLFLAG_MPSAFE, 0, ""); #define CORE_BUF_SIZE (16 * 1024) int __elfN(fallback_brand) = -1; SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, fallback_brand, CTLFLAG_RWTUN, &__elfN(fallback_brand), 0, __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort"); static int elf_legacy_coredump = 0; SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, &elf_legacy_coredump, 0, "include all and only RW pages in core dumps"); int __elfN(nxstack) = #if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */ || \ (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__) || \ defined(__riscv) 1; #else 0; #endif SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, nxstack, CTLFLAG_RW, &__elfN(nxstack), 0, __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack"); #if __ELF_WORD_SIZE == 32 && (defined(__amd64__) || defined(__i386__)) int i386_read_exec = 0; SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_RW, &i386_read_exec, 0, "enable execution from readable segments"); #endif static u_long __elfN(pie_base) = ET_DYN_LOAD_ADDR; static int sysctl_pie_base(SYSCTL_HANDLER_ARGS) { u_long val; int error; val = __elfN(pie_base); error = sysctl_handle_long(oidp, &val, 0, req); if (error != 0 || req->newptr == NULL) return (error); if ((val & PAGE_MASK) != 0) return (EINVAL); __elfN(pie_base) = val; return (0); } SYSCTL_PROC(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, pie_base, CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_pie_base, "LU", "PIE load base without randomization"); SYSCTL_NODE(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, aslr, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, ""); #define ASLR_NODE_OID __CONCAT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), _aslr) static int __elfN(aslr_enabled) = 0; SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, enable, CTLFLAG_RWTUN, &__elfN(aslr_enabled), 0, __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable address map randomization"); static int __elfN(pie_aslr_enabled) = 0; SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, pie_enable, CTLFLAG_RWTUN, &__elfN(pie_aslr_enabled), 0, __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable address map randomization for PIE binaries"); static int __elfN(aslr_honor_sbrk) = 1; SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, honor_sbrk, CTLFLAG_RW, &__elfN(aslr_honor_sbrk), 0, __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": assume sbrk is used"); static int __elfN(aslr_stack_gap) = 3; SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, stack_gap, CTLFLAG_RW, &__elfN(aslr_stack_gap), 0, __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": maximum percentage of main stack to waste on a random gap"); static int __elfN(sigfastblock) = 1; SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, sigfastblock, CTLFLAG_RWTUN, &__elfN(sigfastblock), 0, "enable sigfastblock for new processes"); static bool __elfN(allow_wx) = true; SYSCTL_BOOL(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, allow_wx, CTLFLAG_RWTUN, &__elfN(allow_wx), 0, "Allow pages to be mapped simultaneously writable and executable"); static Elf_Brandinfo *elf_brand_list[MAX_BRANDS]; #define aligned(a, t) (rounddown2((u_long)(a), sizeof(t)) == (u_long)(a)) static const char FREEBSD_ABI_VENDOR[] = "FreeBSD"; Elf_Brandnote __elfN(freebsd_brandnote) = { .hdr.n_namesz = sizeof(FREEBSD_ABI_VENDOR), .hdr.n_descsz = sizeof(int32_t), .hdr.n_type = NT_FREEBSD_ABI_TAG, .vendor = FREEBSD_ABI_VENDOR, .flags = BN_TRANSLATE_OSREL, .trans_osrel = __elfN(freebsd_trans_osrel) }; static bool __elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel) { uintptr_t p; p = (uintptr_t)(note + 1); p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE); *osrel = *(const int32_t *)(p); return (true); } static const char GNU_ABI_VENDOR[] = "GNU"; static int GNU_KFREEBSD_ABI_DESC = 3; Elf_Brandnote __elfN(kfreebsd_brandnote) = { .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), .hdr.n_descsz = 16, /* XXX at least 16 */ .hdr.n_type = 1, .vendor = GNU_ABI_VENDOR, .flags = BN_TRANSLATE_OSREL, .trans_osrel = kfreebsd_trans_osrel }; static bool kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel) { const Elf32_Word *desc; uintptr_t p; p = (uintptr_t)(note + 1); p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE); desc = (const Elf32_Word *)p; if (desc[0] != GNU_KFREEBSD_ABI_DESC) return (false); /* * Debian GNU/kFreeBSD embed the earliest compatible kernel version * (__FreeBSD_version: Rxx) in the LSB way. */ *osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3]; return (true); } int __elfN(insert_brand_entry)(Elf_Brandinfo *entry) { int i; for (i = 0; i < MAX_BRANDS; i++) { if (elf_brand_list[i] == NULL) { elf_brand_list[i] = entry; break; } } if (i == MAX_BRANDS) { printf("WARNING: %s: could not insert brandinfo entry: %p\n", __func__, entry); return (-1); } return (0); } int __elfN(remove_brand_entry)(Elf_Brandinfo *entry) { int i; for (i = 0; i < MAX_BRANDS; i++) { if (elf_brand_list[i] == entry) { elf_brand_list[i] = NULL; break; } } if (i == MAX_BRANDS) return (-1); return (0); } int __elfN(brand_inuse)(Elf_Brandinfo *entry) { struct proc *p; int rval = FALSE; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { if (p->p_sysent == entry->sysvec) { rval = TRUE; break; } } sx_sunlock(&allproc_lock); return (rval); } static Elf_Brandinfo * __elfN(get_brandinfo)(struct image_params *imgp, const char *interp, int32_t *osrel, uint32_t *fctl0) { const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; Elf_Brandinfo *bi, *bi_m; boolean_t ret, has_fctl0; int i, interp_name_len; interp_name_len = interp != NULL ? strlen(interp) + 1 : 0; /* * We support four types of branding -- (1) the ELF EI_OSABI field * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string * branding w/in the ELF header, (3) path of the `interp_path' * field, and (4) the ".note.ABI-tag" ELF section. */ /* Look for an ".note.ABI-tag" ELF section */ bi_m = NULL; for (i = 0; i < MAX_BRANDS; i++) { bi = elf_brand_list[i]; if (bi == NULL) continue; if (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0) continue; if (hdr->e_machine == bi->machine && (bi->flags & (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) { has_fctl0 = false; *fctl0 = 0; *osrel = 0; ret = __elfN(check_note)(imgp, bi->brand_note, osrel, &has_fctl0, fctl0); /* Give brand a chance to veto check_note's guess */ if (ret && bi->header_supported) { ret = bi->header_supported(imgp, osrel, has_fctl0 ? fctl0 : NULL); } /* * If note checker claimed the binary, but the * interpreter path in the image does not * match default one for the brand, try to * search for other brands with the same * interpreter. Either there is better brand * with the right interpreter, or, failing * this, we return first brand which accepted * our note and, optionally, header. */ if (ret && bi_m == NULL && interp != NULL && (bi->interp_path == NULL || (strlen(bi->interp_path) + 1 != interp_name_len || strncmp(interp, bi->interp_path, interp_name_len) != 0))) { bi_m = bi; ret = 0; } if (ret) return (bi); } } if (bi_m != NULL) return (bi_m); /* If the executable has a brand, search for it in the brand list. */ for (i = 0; i < MAX_BRANDS; i++) { bi = elf_brand_list[i]; if (bi == NULL || (bi->flags & BI_BRAND_NOTE_MANDATORY) != 0 || (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0)) continue; if (hdr->e_machine == bi->machine && (hdr->e_ident[EI_OSABI] == bi->brand || (bi->compat_3_brand != NULL && strcmp((const char *)&hdr->e_ident[OLD_EI_BRAND], bi->compat_3_brand) == 0))) { /* Looks good, but give brand a chance to veto */ if (bi->header_supported == NULL || bi->header_supported(imgp, NULL, NULL)) { /* * Again, prefer strictly matching * interpreter path. */ if (interp_name_len == 0 && bi->interp_path == NULL) return (bi); if (bi->interp_path != NULL && strlen(bi->interp_path) + 1 == interp_name_len && strncmp(interp, bi->interp_path, interp_name_len) == 0) return (bi); if (bi_m == NULL) bi_m = bi; } } } if (bi_m != NULL) return (bi_m); /* No known brand, see if the header is recognized by any brand */ for (i = 0; i < MAX_BRANDS; i++) { bi = elf_brand_list[i]; if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY || bi->header_supported == NULL) continue; if (hdr->e_machine == bi->machine) { ret = bi->header_supported(imgp, NULL, NULL); if (ret) return (bi); } } /* Lacking a known brand, search for a recognized interpreter. */ if (interp != NULL) { for (i = 0; i < MAX_BRANDS; i++) { bi = elf_brand_list[i]; if (bi == NULL || (bi->flags & (BI_BRAND_NOTE_MANDATORY | BI_BRAND_ONLY_STATIC)) != 0) continue; if (hdr->e_machine == bi->machine && bi->interp_path != NULL && /* ELF image p_filesz includes terminating zero */ strlen(bi->interp_path) + 1 == interp_name_len && strncmp(interp, bi->interp_path, interp_name_len) == 0 && (bi->header_supported == NULL || bi->header_supported(imgp, NULL, NULL))) return (bi); } } /* Lacking a recognized interpreter, try the default brand */ for (i = 0; i < MAX_BRANDS; i++) { bi = elf_brand_list[i]; if (bi == NULL || (bi->flags & BI_BRAND_NOTE_MANDATORY) != 0 || (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0)) continue; if (hdr->e_machine == bi->machine && __elfN(fallback_brand) == bi->brand && (bi->header_supported == NULL || bi->header_supported(imgp, NULL, NULL))) return (bi); } return (NULL); } static bool __elfN(phdr_in_zero_page)(const Elf_Ehdr *hdr) { return (hdr->e_phoff <= PAGE_SIZE && (u_int)hdr->e_phentsize * hdr->e_phnum <= PAGE_SIZE - hdr->e_phoff); } static int __elfN(check_header)(const Elf_Ehdr *hdr) { Elf_Brandinfo *bi; int i; if (!IS_ELF(*hdr) || hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || hdr->e_ident[EI_DATA] != ELF_TARG_DATA || hdr->e_ident[EI_VERSION] != EV_CURRENT || hdr->e_phentsize != sizeof(Elf_Phdr) || hdr->e_version != ELF_TARG_VER) return (ENOEXEC); /* * Make sure we have at least one brand for this machine. */ for (i = 0; i < MAX_BRANDS; i++) { bi = elf_brand_list[i]; if (bi != NULL && bi->machine == hdr->e_machine) break; } if (i == MAX_BRANDS) return (ENOEXEC); return (0); } static int __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset, vm_offset_t start, vm_offset_t end, vm_prot_t prot) { struct sf_buf *sf; int error; vm_offset_t off; /* * Create the page if it doesn't exist yet. Ignore errors. */ vm_map_fixed(map, NULL, 0, trunc_page(start), round_page(end) - trunc_page(start), VM_PROT_ALL, VM_PROT_ALL, MAP_CHECK_EXCL); /* * Find the page from the underlying object. */ if (object != NULL) { sf = vm_imgact_map_page(object, offset); if (sf == NULL) return (KERN_FAILURE); off = offset - trunc_page(offset); error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start, end - start); vm_imgact_unmap_page(sf); if (error != 0) return (KERN_FAILURE); } return (KERN_SUCCESS); } static int __elfN(map_insert)(struct image_params *imgp, vm_map_t map, vm_object_t object, vm_ooffset_t offset, vm_offset_t start, vm_offset_t end, vm_prot_t prot, int cow) { struct sf_buf *sf; vm_offset_t off; vm_size_t sz; int error, locked, rv; if (start != trunc_page(start)) { rv = __elfN(map_partial)(map, object, offset, start, round_page(start), prot); if (rv != KERN_SUCCESS) return (rv); offset += round_page(start) - start; start = round_page(start); } if (end != round_page(end)) { rv = __elfN(map_partial)(map, object, offset + trunc_page(end) - start, trunc_page(end), end, prot); if (rv != KERN_SUCCESS) return (rv); end = trunc_page(end); } if (start >= end) return (KERN_SUCCESS); if ((offset & PAGE_MASK) != 0) { /* * The mapping is not page aligned. This means that we have * to copy the data. */ rv = vm_map_fixed(map, NULL, 0, start, end - start, prot | VM_PROT_WRITE, VM_PROT_ALL, MAP_CHECK_EXCL); if (rv != KERN_SUCCESS) return (rv); if (object == NULL) return (KERN_SUCCESS); for (; start < end; start += sz) { sf = vm_imgact_map_page(object, offset); if (sf == NULL) return (KERN_FAILURE); off = offset - trunc_page(offset); sz = end - start; if (sz > PAGE_SIZE - off) sz = PAGE_SIZE - off; error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start, sz); vm_imgact_unmap_page(sf); if (error != 0) return (KERN_FAILURE); offset += sz; } } else { vm_object_reference(object); rv = vm_map_fixed(map, object, offset, start, end - start, prot, VM_PROT_ALL, cow | MAP_CHECK_EXCL | (object != NULL ? MAP_VN_EXEC : 0)); if (rv != KERN_SUCCESS) { locked = VOP_ISLOCKED(imgp->vp); VOP_UNLOCK(imgp->vp); vm_object_deallocate(object); vn_lock(imgp->vp, locked | LK_RETRY); return (rv); } else if (object != NULL) { MPASS(imgp->vp->v_object == object); VOP_SET_TEXT_CHECKED(imgp->vp); } } return (KERN_SUCCESS); } static int __elfN(load_section)(struct image_params *imgp, vm_ooffset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot) { struct sf_buf *sf; size_t map_len; vm_map_t map; vm_object_t object; vm_offset_t map_addr; int error, rv, cow; size_t copy_len; vm_ooffset_t file_addr; /* * It's necessary to fail if the filsz + offset taken from the * header is greater than the actual file pager object's size. * If we were to allow this, then the vm_map_find() below would * walk right off the end of the file object and into the ether. * * While I'm here, might as well check for something else that * is invalid: filsz cannot be greater than memsz. */ if ((filsz != 0 && (off_t)filsz + offset > imgp->attr->va_size) || filsz > memsz) { uprintf("elf_load_section: truncated ELF file\n"); return (ENOEXEC); } object = imgp->object; map = &imgp->proc->p_vmspace->vm_map; map_addr = trunc_page((vm_offset_t)vmaddr); file_addr = trunc_page(offset); /* * We have two choices. We can either clear the data in the last page * of an oversized mapping, or we can start the anon mapping a page * early and copy the initialized data into that first page. We * choose the second. */ if (filsz == 0) map_len = 0; else if (memsz > filsz) map_len = trunc_page(offset + filsz) - file_addr; else map_len = round_page(offset + filsz) - file_addr; if (map_len != 0) { /* cow flags: don't dump readonly sections in core */ cow = MAP_COPY_ON_WRITE | MAP_PREFAULT | (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP); rv = __elfN(map_insert)(imgp, map, object, file_addr, map_addr, map_addr + map_len, prot, cow); if (rv != KERN_SUCCESS) return (EINVAL); /* we can stop now if we've covered it all */ if (memsz == filsz) return (0); } /* * We have to get the remaining bit of the file into the first part * of the oversized map segment. This is normally because the .data * segment in the file is extended to provide bss. It's a neat idea * to try and save a page, but it's a pain in the behind to implement. */ copy_len = filsz == 0 ? 0 : (offset + filsz) - trunc_page(offset + filsz); map_addr = trunc_page((vm_offset_t)vmaddr + filsz); map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr; /* This had damn well better be true! */ if (map_len != 0) { rv = __elfN(map_insert)(imgp, map, NULL, 0, map_addr, map_addr + map_len, prot, 0); if (rv != KERN_SUCCESS) return (EINVAL); } if (copy_len != 0) { sf = vm_imgact_map_page(object, offset + filsz); if (sf == NULL) return (EIO); /* send the page fragment to user space */ error = copyout((caddr_t)sf_buf_kva(sf), (caddr_t)map_addr, copy_len); vm_imgact_unmap_page(sf); if (error != 0) return (error); } /* * Remove write access to the page if it was only granted by map_insert * to allow copyout. */ if ((prot & VM_PROT_WRITE) == 0) vm_map_protect(map, trunc_page(map_addr), round_page(map_addr + map_len), prot, 0, VM_MAP_PROTECT_SET_PROT); return (0); } static int __elfN(load_sections)(struct image_params *imgp, const Elf_Ehdr *hdr, const Elf_Phdr *phdr, u_long rbase, u_long *base_addrp) { vm_prot_t prot; u_long base_addr; bool first; int error, i; ASSERT_VOP_LOCKED(imgp->vp, __func__); base_addr = 0; first = true; for (i = 0; i < hdr->e_phnum; i++) { if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0) continue; /* Loadable segment */ prot = __elfN(trans_prot)(phdr[i].p_flags); error = __elfN(load_section)(imgp, phdr[i].p_offset, (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase, phdr[i].p_memsz, phdr[i].p_filesz, prot); if (error != 0) return (error); /* * Establish the base address if this is the first segment. */ if (first) { base_addr = trunc_page(phdr[i].p_vaddr + rbase); first = false; } } if (base_addrp != NULL) *base_addrp = base_addr; return (0); } /* * Load the file "file" into memory. It may be either a shared object * or an executable. * * The "addr" reference parameter is in/out. On entry, it specifies * the address where a shared object should be loaded. If the file is * an executable, this value is ignored. On exit, "addr" specifies * where the file was actually loaded. * * The "entry" reference parameter is out only. On exit, it specifies * the entry point for the loaded file. */ static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr, u_long *entry) { struct { struct nameidata nd; struct vattr attr; struct image_params image_params; } *tempdata; const Elf_Ehdr *hdr = NULL; const Elf_Phdr *phdr = NULL; struct nameidata *nd; struct vattr *attr; struct image_params *imgp; u_long rbase; u_long base_addr = 0; int error; #ifdef CAPABILITY_MODE /* * XXXJA: This check can go away once we are sufficiently confident * that the checks in namei() are correct. */ if (IN_CAPABILITY_MODE(curthread)) return (ECAPMODE); #endif tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK | M_ZERO); nd = &tempdata->nd; attr = &tempdata->attr; imgp = &tempdata->image_params; /* * Initialize part of the common data */ imgp->proc = p; imgp->attr = attr; NDINIT(nd, LOOKUP, ISOPEN | FOLLOW | LOCKSHARED | LOCKLEAF, UIO_SYSSPACE, file, curthread); if ((error = namei(nd)) != 0) { nd->ni_vp = NULL; goto fail; } NDFREE(nd, NDF_ONLY_PNBUF); imgp->vp = nd->ni_vp; /* * Check permissions, modes, uid, etc on the file, and "open" it. */ error = exec_check_permissions(imgp); if (error) goto fail; error = exec_map_first_page(imgp); if (error) goto fail; imgp->object = nd->ni_vp->v_object; hdr = (const Elf_Ehdr *)imgp->image_header; if ((error = __elfN(check_header)(hdr)) != 0) goto fail; if (hdr->e_type == ET_DYN) rbase = *addr; else if (hdr->e_type == ET_EXEC) rbase = 0; else { error = ENOEXEC; goto fail; } /* Only support headers that fit within first page for now */ if (!__elfN(phdr_in_zero_page)(hdr)) { error = ENOEXEC; goto fail; } phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); if (!aligned(phdr, Elf_Addr)) { error = ENOEXEC; goto fail; } error = __elfN(load_sections)(imgp, hdr, phdr, rbase, &base_addr); if (error != 0) goto fail; *addr = base_addr; *entry = (unsigned long)hdr->e_entry + rbase; fail: if (imgp->firstpage) exec_unmap_first_page(imgp); if (nd->ni_vp) { if (imgp->textset) VOP_UNSET_TEXT_CHECKED(nd->ni_vp); vput(nd->ni_vp); } free(tempdata, M_TEMP); return (error); } static u_long __CONCAT(rnd_, __elfN(base))(vm_map_t map __unused, u_long minv, u_long maxv, u_int align) { u_long rbase, res; MPASS(vm_map_min(map) <= minv); MPASS(maxv <= vm_map_max(map)); MPASS(minv < maxv); MPASS(minv + align < maxv); arc4rand(&rbase, sizeof(rbase), 0); res = roundup(minv, (u_long)align) + rbase % (maxv - minv); res &= ~((u_long)align - 1); if (res >= maxv) res -= align; KASSERT(res >= minv, ("res %#lx < minv %#lx, maxv %#lx rbase %#lx", res, minv, maxv, rbase)); KASSERT(res < maxv, ("res %#lx > maxv %#lx, minv %#lx rbase %#lx", res, maxv, minv, rbase)); return (res); } static int __elfN(enforce_limits)(struct image_params *imgp, const Elf_Ehdr *hdr, const Elf_Phdr *phdr, u_long et_dyn_addr) { struct vmspace *vmspace; const char *err_str; u_long text_size, data_size, total_size, text_addr, data_addr; u_long seg_size, seg_addr; int i; err_str = NULL; text_size = data_size = total_size = text_addr = data_addr = 0; for (i = 0; i < hdr->e_phnum; i++) { if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0) continue; seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr); seg_size = round_page(phdr[i].p_memsz + phdr[i].p_vaddr + et_dyn_addr - seg_addr); /* * Make the largest executable segment the official * text segment and all others data. * * Note that obreak() assumes that data_addr + data_size == end * of data load area, and the ELF file format expects segments * to be sorted by address. If multiple data segments exist, * the last one will be used. */ if ((phdr[i].p_flags & PF_X) != 0 && text_size < seg_size) { text_size = seg_size; text_addr = seg_addr; } else { data_size = seg_size; data_addr = seg_addr; } total_size += seg_size; } if (data_addr == 0 && data_size == 0) { data_addr = text_addr; data_size = text_size; } /* * Check limits. It should be safe to check the * limits after loading the segments since we do * not actually fault in all the segments pages. */ PROC_LOCK(imgp->proc); if (data_size > lim_cur_proc(imgp->proc, RLIMIT_DATA)) err_str = "Data segment size exceeds process limit"; else if (text_size > maxtsiz) err_str = "Text segment size exceeds system limit"; else if (total_size > lim_cur_proc(imgp->proc, RLIMIT_VMEM)) err_str = "Total segment size exceeds process limit"; else if (racct_set(imgp->proc, RACCT_DATA, data_size) != 0) err_str = "Data segment size exceeds resource limit"; else if (racct_set(imgp->proc, RACCT_VMEM, total_size) != 0) err_str = "Total segment size exceeds resource limit"; PROC_UNLOCK(imgp->proc); if (err_str != NULL) { uprintf("%s\n", err_str); return (ENOMEM); } vmspace = imgp->proc->p_vmspace; vmspace->vm_tsize = text_size >> PAGE_SHIFT; vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; vmspace->vm_dsize = data_size >> PAGE_SHIFT; vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; return (0); } static int __elfN(get_interp)(struct image_params *imgp, const Elf_Phdr *phdr, char **interpp, bool *free_interpp) { struct thread *td; char *interp; int error, interp_name_len; KASSERT(phdr->p_type == PT_INTERP, ("%s: p_type %u != PT_INTERP", __func__, phdr->p_type)); ASSERT_VOP_LOCKED(imgp->vp, __func__); td = curthread; /* Path to interpreter */ if (phdr->p_filesz < 2 || phdr->p_filesz > MAXPATHLEN) { uprintf("Invalid PT_INTERP\n"); return (ENOEXEC); } interp_name_len = phdr->p_filesz; if (phdr->p_offset > PAGE_SIZE || interp_name_len > PAGE_SIZE - phdr->p_offset) { /* * The vnode lock might be needed by the pagedaemon to * clean pages owned by the vnode. Do not allow sleep * waiting for memory with the vnode locked, instead * try non-sleepable allocation first, and if it * fails, go to the slow path were we drop the lock * and do M_WAITOK. A text reference prevents * modifications to the vnode content. */ interp = malloc(interp_name_len + 1, M_TEMP, M_NOWAIT); if (interp == NULL) { VOP_UNLOCK(imgp->vp); interp = malloc(interp_name_len + 1, M_TEMP, M_WAITOK); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); } error = vn_rdwr(UIO_READ, imgp->vp, interp, interp_name_len, phdr->p_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL, td); if (error != 0) { free(interp, M_TEMP); uprintf("i/o error PT_INTERP %d\n", error); return (error); } interp[interp_name_len] = '\0'; *interpp = interp; *free_interpp = true; return (0); } interp = __DECONST(char *, imgp->image_header) + phdr->p_offset; if (interp[interp_name_len - 1] != '\0') { uprintf("Invalid PT_INTERP\n"); return (ENOEXEC); } *interpp = interp; *free_interpp = false; return (0); } static int __elfN(load_interp)(struct image_params *imgp, const Elf_Brandinfo *brand_info, const char *interp, u_long *addr, u_long *entry) { char *path; int error; if (brand_info->emul_path != NULL && brand_info->emul_path[0] != '\0') { path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); snprintf(path, MAXPATHLEN, "%s%s", brand_info->emul_path, interp); error = __elfN(load_file)(imgp->proc, path, addr, entry); free(path, M_TEMP); if (error == 0) return (0); } if (brand_info->interp_newpath != NULL && (brand_info->interp_path == NULL || strcmp(interp, brand_info->interp_path) == 0)) { error = __elfN(load_file)(imgp->proc, brand_info->interp_newpath, addr, entry); if (error == 0) return (0); } error = __elfN(load_file)(imgp->proc, interp, addr, entry); if (error == 0) return (0); uprintf("ELF interpreter %s not found, error %d\n", interp, error); return (error); } /* * Impossible et_dyn_addr initial value indicating that the real base * must be calculated later with some randomization applied. */ #define ET_DYN_ADDR_RAND 1 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp) { struct thread *td; const Elf_Ehdr *hdr; const Elf_Phdr *phdr; Elf_Auxargs *elf_auxargs; struct vmspace *vmspace; vm_map_t map; char *interp; Elf_Brandinfo *brand_info; struct sysentvec *sv; u_long addr, baddr, et_dyn_addr, entry, proghdr; u_long maxalign, mapsz, maxv, maxv1; uint32_t fctl0; int32_t osrel; bool free_interp; int error, i, n; hdr = (const Elf_Ehdr *)imgp->image_header; /* * Do we have a valid ELF header ? * * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later * if particular brand doesn't support it. */ if (__elfN(check_header)(hdr) != 0 || (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)) return (-1); /* * From here on down, we return an errno, not -1, as we've * detected an ELF file. */ if (!__elfN(phdr_in_zero_page)(hdr)) { uprintf("Program headers not in the first page\n"); return (ENOEXEC); } phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); if (!aligned(phdr, Elf_Addr)) { uprintf("Unaligned program headers\n"); return (ENOEXEC); } n = error = 0; baddr = 0; osrel = 0; fctl0 = 0; entry = proghdr = 0; interp = NULL; free_interp = false; td = curthread; maxalign = PAGE_SIZE; mapsz = 0; for (i = 0; i < hdr->e_phnum; i++) { switch (phdr[i].p_type) { case PT_LOAD: if (n == 0) baddr = phdr[i].p_vaddr; if (phdr[i].p_align > maxalign) maxalign = phdr[i].p_align; mapsz += phdr[i].p_memsz; n++; /* * If this segment contains the program headers, * remember their virtual address for the AT_PHDR * aux entry. Static binaries don't usually include * a PT_PHDR entry. */ if (phdr[i].p_offset == 0 && hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize <= phdr[i].p_filesz) proghdr = phdr[i].p_vaddr + hdr->e_phoff; break; case PT_INTERP: /* Path to interpreter */ if (interp != NULL) { uprintf("Multiple PT_INTERP headers\n"); error = ENOEXEC; goto ret; } error = __elfN(get_interp)(imgp, &phdr[i], &interp, &free_interp); if (error != 0) goto ret; break; case PT_GNU_STACK: if (__elfN(nxstack)) imgp->stack_prot = __elfN(trans_prot)(phdr[i].p_flags); imgp->stack_sz = phdr[i].p_memsz; break; case PT_PHDR: /* Program header table info */ proghdr = phdr[i].p_vaddr; break; } } brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel, &fctl0); if (brand_info == NULL) { uprintf("ELF binary type \"%u\" not known.\n", hdr->e_ident[EI_OSABI]); error = ENOEXEC; goto ret; } sv = brand_info->sysvec; et_dyn_addr = 0; if (hdr->e_type == ET_DYN) { if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) { uprintf("Cannot execute shared object\n"); error = ENOEXEC; goto ret; } /* * Honour the base load address from the dso if it is * non-zero for some reason. */ if (baddr == 0) { if ((sv->sv_flags & SV_ASLR) == 0 || (fctl0 & NT_FREEBSD_FCTL_ASLR_DISABLE) != 0) et_dyn_addr = __elfN(pie_base); else if ((__elfN(pie_aslr_enabled) && (imgp->proc->p_flag2 & P2_ASLR_DISABLE) == 0) || (imgp->proc->p_flag2 & P2_ASLR_ENABLE) != 0) et_dyn_addr = ET_DYN_ADDR_RAND; else et_dyn_addr = __elfN(pie_base); } } /* * Avoid a possible deadlock if the current address space is destroyed * and that address space maps the locked vnode. In the common case, * the locked vnode's v_usecount is decremented but remains greater * than zero. Consequently, the vnode lock is not needed by vrele(). * However, in cases where the vnode lock is external, such as nullfs, * v_usecount may become zero. * * The VV_TEXT flag prevents modifications to the executable while * the vnode is unlocked. */ VOP_UNLOCK(imgp->vp); /* * Decide whether to enable randomization of user mappings. * First, reset user preferences for the setid binaries. * Then, account for the support of the randomization by the * ABI, by user preferences, and make special treatment for * PIE binaries. */ if (imgp->credential_setid) { PROC_LOCK(imgp->proc); imgp->proc->p_flag2 &= ~(P2_ASLR_ENABLE | P2_ASLR_DISABLE | P2_WXORX_DISABLE | P2_WXORX_ENABLE_EXEC); PROC_UNLOCK(imgp->proc); } if ((sv->sv_flags & SV_ASLR) == 0 || (imgp->proc->p_flag2 & P2_ASLR_DISABLE) != 0 || (fctl0 & NT_FREEBSD_FCTL_ASLR_DISABLE) != 0) { KASSERT(et_dyn_addr != ET_DYN_ADDR_RAND, ("et_dyn_addr == RAND and !ASLR")); } else if ((imgp->proc->p_flag2 & P2_ASLR_ENABLE) != 0 || (__elfN(aslr_enabled) && hdr->e_type == ET_EXEC) || et_dyn_addr == ET_DYN_ADDR_RAND) { imgp->map_flags |= MAP_ASLR; /* * If user does not care about sbrk, utilize the bss * grow region for mappings as well. We can select * the base for the image anywere and still not suffer * from the fragmentation. */ if (!__elfN(aslr_honor_sbrk) || (imgp->proc->p_flag2 & P2_ASLR_IGNSTART) != 0) imgp->map_flags |= MAP_ASLR_IGNSTART; } if ((!__elfN(allow_wx) && (fctl0 & NT_FREEBSD_FCTL_WXNEEDED) == 0 && (imgp->proc->p_flag2 & P2_WXORX_DISABLE) == 0) || (imgp->proc->p_flag2 & P2_WXORX_ENABLE_EXEC) != 0) imgp->map_flags |= MAP_WXORX; error = exec_new_vmspace(imgp, sv); vmspace = imgp->proc->p_vmspace; map = &vmspace->vm_map; imgp->proc->p_sysent = sv; maxv = vm_map_max(map) - lim_max(td, RLIMIT_STACK); if (et_dyn_addr == ET_DYN_ADDR_RAND) { KASSERT((map->flags & MAP_ASLR) != 0, ("ET_DYN_ADDR_RAND but !MAP_ASLR")); et_dyn_addr = __CONCAT(rnd_, __elfN(base))(map, vm_map_min(map) + mapsz + lim_max(td, RLIMIT_DATA), /* reserve half of the address space to interpreter */ maxv / 2, 1UL << flsl(maxalign)); } vn_lock(imgp->vp, LK_SHARED | LK_RETRY); if (error != 0) goto ret; error = __elfN(load_sections)(imgp, hdr, phdr, et_dyn_addr, NULL); if (error != 0) goto ret; error = __elfN(enforce_limits)(imgp, hdr, phdr, et_dyn_addr); if (error != 0) goto ret; entry = (u_long)hdr->e_entry + et_dyn_addr; /* * We load the dynamic linker where a userland call * to mmap(0, ...) would put it. The rationale behind this * calculation is that it leaves room for the heap to grow to * its maximum allowed size. */ addr = round_page((vm_offset_t)vmspace->vm_daddr + lim_max(td, RLIMIT_DATA)); if ((map->flags & MAP_ASLR) != 0) { maxv1 = maxv / 2 + addr / 2; MPASS(maxv1 >= addr); /* No overflow */ map->anon_loc = __CONCAT(rnd_, __elfN(base))(map, addr, maxv1, (MAXPAGESIZES > 1 && pagesizes[1] != 0) ? pagesizes[1] : pagesizes[0]); } else { map->anon_loc = addr; } imgp->entry_addr = entry; if (interp != NULL) { VOP_UNLOCK(imgp->vp); if ((map->flags & MAP_ASLR) != 0) { /* Assume that interpreter fits into 1/4 of AS */ maxv1 = maxv / 2 + addr / 2; MPASS(maxv1 >= addr); /* No overflow */ addr = __CONCAT(rnd_, __elfN(base))(map, addr, maxv1, PAGE_SIZE); } error = __elfN(load_interp)(imgp, brand_info, interp, &addr, &imgp->entry_addr); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); if (error != 0) goto ret; } else addr = et_dyn_addr; /* * Construct auxargs table (used by the copyout_auxargs routine) */ elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_NOWAIT); if (elf_auxargs == NULL) { VOP_UNLOCK(imgp->vp); elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); } elf_auxargs->execfd = -1; elf_auxargs->phdr = proghdr + et_dyn_addr; elf_auxargs->phent = hdr->e_phentsize; elf_auxargs->phnum = hdr->e_phnum; elf_auxargs->pagesz = PAGE_SIZE; elf_auxargs->base = addr; elf_auxargs->flags = 0; elf_auxargs->entry = entry; elf_auxargs->hdr_eflags = hdr->e_flags; imgp->auxargs = elf_auxargs; imgp->interpreted = 0; imgp->reloc_base = addr; imgp->proc->p_osrel = osrel; imgp->proc->p_fctl0 = fctl0; imgp->proc->p_elf_machine = hdr->e_machine; imgp->proc->p_elf_flags = hdr->e_flags; ret: if (free_interp) free(interp, M_TEMP); return (error); } #define elf_suword __CONCAT(suword, __ELF_WORD_SIZE) int __elfN(freebsd_copyout_auxargs)(struct image_params *imgp, uintptr_t base) { Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; Elf_Auxinfo *argarray, *pos; int error; argarray = pos = malloc(AT_COUNT * sizeof(*pos), M_TEMP, M_WAITOK | M_ZERO); if (args->execfd != -1) AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); AUXARGS_ENTRY(pos, AT_PHENT, args->phent); AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); AUXARGS_ENTRY(pos, AT_BASE, args->base); AUXARGS_ENTRY(pos, AT_EHDRFLAGS, args->hdr_eflags); if (imgp->execpathp != 0) AUXARGS_ENTRY_PTR(pos, AT_EXECPATH, imgp->execpathp); AUXARGS_ENTRY(pos, AT_OSRELDATE, imgp->proc->p_ucred->cr_prison->pr_osreldate); if (imgp->canary != 0) { AUXARGS_ENTRY_PTR(pos, AT_CANARY, imgp->canary); AUXARGS_ENTRY(pos, AT_CANARYLEN, imgp->canarylen); } AUXARGS_ENTRY(pos, AT_NCPUS, mp_ncpus); if (imgp->pagesizes != 0) { AUXARGS_ENTRY_PTR(pos, AT_PAGESIZES, imgp->pagesizes); AUXARGS_ENTRY(pos, AT_PAGESIZESLEN, imgp->pagesizeslen); } if (imgp->sysent->sv_timekeep_base != 0) { AUXARGS_ENTRY(pos, AT_TIMEKEEP, imgp->sysent->sv_timekeep_base); } AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot : imgp->sysent->sv_stackprot); if (imgp->sysent->sv_hwcap != NULL) AUXARGS_ENTRY(pos, AT_HWCAP, *imgp->sysent->sv_hwcap); if (imgp->sysent->sv_hwcap2 != NULL) AUXARGS_ENTRY(pos, AT_HWCAP2, *imgp->sysent->sv_hwcap2); AUXARGS_ENTRY(pos, AT_BSDFLAGS, __elfN(sigfastblock) ? ELF_BSDF_SIGFASTBLK : 0); AUXARGS_ENTRY(pos, AT_ARGC, imgp->args->argc); AUXARGS_ENTRY_PTR(pos, AT_ARGV, imgp->argv); AUXARGS_ENTRY(pos, AT_ENVC, imgp->args->envc); AUXARGS_ENTRY_PTR(pos, AT_ENVV, imgp->envv); 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); AUXARGS_ENTRY(pos, AT_NULL, 0); free(imgp->auxargs, M_TEMP); imgp->auxargs = NULL; KASSERT(pos - argarray <= AT_COUNT, ("Too many auxargs")); error = copyout(argarray, (void *)base, sizeof(*argarray) * AT_COUNT); free(argarray, M_TEMP); return (error); } int __elfN(freebsd_fixup)(uintptr_t *stack_base, struct image_params *imgp) { Elf_Addr *base; base = (Elf_Addr *)*stack_base; base--; if (elf_suword(base, imgp->args->argc) == -1) return (EFAULT); *stack_base = (uintptr_t)base; return (0); } /* * Code for generating ELF core dumps. */ typedef void (*segment_callback)(vm_map_entry_t, void *); /* Closure for cb_put_phdr(). */ struct phdr_closure { Elf_Phdr *phdr; /* Program header to fill in */ Elf_Off offset; /* Offset of segment in core file */ }; /* Closure for cb_size_segment(). */ struct sseg_closure { int count; /* Count of writable segments. */ size_t size; /* Total size of all writable segments. */ }; typedef void (*outfunc_t)(void *, struct sbuf *, size_t *); struct note_info { int type; /* Note type. */ outfunc_t outfunc; /* Output function. */ void *outarg; /* Argument for the output function. */ size_t outsize; /* Output size. */ TAILQ_ENTRY(note_info) link; /* Link to the next note info. */ }; TAILQ_HEAD(note_info_list, note_info); /* Coredump output parameters. */ struct coredump_params { off_t offset; struct ucred *active_cred; struct ucred *file_cred; struct thread *td; struct vnode *vp; struct compressor *comp; }; extern int compress_user_cores; extern int compress_user_cores_level; static void cb_put_phdr(vm_map_entry_t, void *); static void cb_size_segment(vm_map_entry_t, void *); static int core_write(struct coredump_params *, const void *, size_t, off_t, enum uio_seg, size_t *); static void each_dumpable_segment(struct thread *, segment_callback, void *, int); static int __elfN(corehdr)(struct coredump_params *, int, void *, size_t, struct note_info_list *, size_t, int); static void __elfN(prepare_notes)(struct thread *, struct note_info_list *, size_t *); static void __elfN(puthdr)(struct thread *, void *, size_t, int, size_t, int); static void __elfN(putnote)(struct note_info *, struct sbuf *); static size_t register_note(struct note_info_list *, int, outfunc_t, void *); static int sbuf_drain_core_output(void *, const char *, int); static void __elfN(note_fpregset)(void *, struct sbuf *, size_t *); static void __elfN(note_prpsinfo)(void *, struct sbuf *, size_t *); static void __elfN(note_prstatus)(void *, struct sbuf *, size_t *); static void __elfN(note_threadmd)(void *, struct sbuf *, size_t *); static void __elfN(note_thrmisc)(void *, struct sbuf *, size_t *); static void __elfN(note_ptlwpinfo)(void *, struct sbuf *, size_t *); static void __elfN(note_procstat_auxv)(void *, struct sbuf *, size_t *); static void __elfN(note_procstat_proc)(void *, struct sbuf *, size_t *); static void __elfN(note_procstat_psstrings)(void *, struct sbuf *, size_t *); static void note_procstat_files(void *, struct sbuf *, size_t *); static void note_procstat_groups(void *, struct sbuf *, size_t *); static void note_procstat_osrel(void *, struct sbuf *, size_t *); static void note_procstat_rlimit(void *, struct sbuf *, size_t *); static void note_procstat_umask(void *, struct sbuf *, size_t *); static void note_procstat_vmmap(void *, struct sbuf *, size_t *); /* * Write out a core segment to the compression stream. */ static int compress_chunk(struct coredump_params *p, char *base, char *buf, u_int len) { u_int chunk_len; int error; while (len > 0) { chunk_len = MIN(len, CORE_BUF_SIZE); /* * We can get EFAULT error here. * In that case zero out the current chunk of the segment. */ error = copyin(base, buf, chunk_len); if (error != 0) bzero(buf, chunk_len); error = compressor_write(p->comp, buf, chunk_len); if (error != 0) break; base += chunk_len; len -= chunk_len; } return (error); } static int core_compressed_write(void *base, size_t len, off_t offset, void *arg) { return (core_write((struct coredump_params *)arg, base, len, offset, UIO_SYSSPACE, NULL)); } static int core_write(struct coredump_params *p, const void *base, size_t len, off_t offset, enum uio_seg seg, size_t *resid) { return (vn_rdwr_inchunks(UIO_WRITE, p->vp, __DECONST(void *, base), len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, p->active_cred, p->file_cred, resid, p->td)); } +extern int core_dump_can_intr; + static int core_output(char *base, size_t len, off_t offset, struct coredump_params *p, void *tmpbuf) { vm_map_t map; struct mount *mp; size_t resid, runlen; int error; bool success; KASSERT((uintptr_t)base % PAGE_SIZE == 0, ("%s: user address %p is not page-aligned", __func__, base)); if (p->comp != NULL) return (compress_chunk(p, base, tmpbuf, len)); map = &p->td->td_proc->p_vmspace->vm_map; for (; len > 0; base += runlen, offset += runlen, len -= runlen) { /* * Attempt to page in all virtual pages in the range. If a * virtual page is not backed by the pager, it is represented as * a hole in the file. This can occur with zero-filled * anonymous memory or truncated files, for example. */ for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { + if (core_dump_can_intr && curproc_sigkilled()) + return (EINTR); error = vm_fault(map, (uintptr_t)base + runlen, VM_PROT_READ, VM_FAULT_NOFILL, NULL); if (runlen == 0) success = error == KERN_SUCCESS; else if ((error == KERN_SUCCESS) != success) break; } if (success) { error = core_write(p, base, runlen, offset, UIO_USERSPACE, &resid); if (error != 0) { if (error != EFAULT) break; /* * EFAULT may be returned if the user mapping * could not be accessed, e.g., because a mapped * file has been truncated. Skip the page if no * progress was made, to protect against a * hypothetical scenario where vm_fault() was * successful but core_write() returns EFAULT * anyway. */ runlen -= resid; if (runlen == 0) { success = false; runlen = PAGE_SIZE; } } } if (!success) { error = vn_start_write(p->vp, &mp, V_WAIT); if (error != 0) break; vn_lock(p->vp, LK_EXCLUSIVE | LK_RETRY); error = vn_truncate_locked(p->vp, offset + runlen, false, p->td->td_ucred); VOP_UNLOCK(p->vp); vn_finished_write(mp); if (error != 0) break; } } return (error); } /* * Drain into a core file. */ static int sbuf_drain_core_output(void *arg, const char *data, int len) { struct coredump_params *p; int error, locked; p = (struct coredump_params *)arg; /* * Some kern_proc out routines that print to this sbuf may * call us with the process lock held. Draining with the * non-sleepable lock held is unsafe. The lock is needed for * those routines when dumping a live process. In our case we * can safely release the lock before draining and acquire * again after. */ locked = PROC_LOCKED(p->td->td_proc); if (locked) PROC_UNLOCK(p->td->td_proc); if (p->comp != NULL) error = compressor_write(p->comp, __DECONST(char *, data), len); else error = core_write(p, __DECONST(void *, data), len, p->offset, UIO_SYSSPACE, NULL); if (locked) PROC_LOCK(p->td->td_proc); if (error != 0) return (-error); p->offset += len; return (len); } int __elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags) { struct ucred *cred = td->td_ucred; int compm, error = 0; struct sseg_closure seginfo; struct note_info_list notelst; struct coredump_params params; struct note_info *ninfo; void *hdr, *tmpbuf; size_t hdrsize, notesz, coresize; hdr = NULL; tmpbuf = NULL; TAILQ_INIT(¬elst); /* Size the program segments. */ seginfo.count = 0; seginfo.size = 0; each_dumpable_segment(td, cb_size_segment, &seginfo, flags); /* * Collect info about the core file header area. */ hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count); if (seginfo.count + 1 >= PN_XNUM) hdrsize += sizeof(Elf_Shdr); __elfN(prepare_notes)(td, ¬elst, ¬esz); coresize = round_page(hdrsize + notesz) + seginfo.size; /* Set up core dump parameters. */ params.offset = 0; params.active_cred = cred; params.file_cred = NOCRED; params.td = td; params.vp = vp; params.comp = NULL; #ifdef RACCT if (racct_enable) { PROC_LOCK(td->td_proc); error = racct_add(td->td_proc, RACCT_CORE, coresize); PROC_UNLOCK(td->td_proc); if (error != 0) { error = EFAULT; goto done; } } #endif if (coresize >= limit) { error = EFAULT; goto done; } /* Create a compression stream if necessary. */ compm = compress_user_cores; if ((flags & (SVC_PT_COREDUMP | SVC_NOCOMPRESS)) == SVC_PT_COREDUMP && compm == 0) compm = COMPRESS_GZIP; if (compm != 0) { params.comp = compressor_init(core_compressed_write, compm, CORE_BUF_SIZE, compress_user_cores_level, ¶ms); if (params.comp == NULL) { error = EFAULT; goto done; } tmpbuf = malloc(CORE_BUF_SIZE, M_TEMP, M_WAITOK | M_ZERO); } /* * Allocate memory for building the header, fill it up, * and write it out following the notes. */ hdr = malloc(hdrsize, M_TEMP, M_WAITOK); error = __elfN(corehdr)(¶ms, seginfo.count, hdr, hdrsize, ¬elst, notesz, flags); /* Write the contents of all of the writable segments. */ if (error == 0) { Elf_Phdr *php; off_t offset; int i; php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; offset = round_page(hdrsize + notesz); for (i = 0; i < seginfo.count; i++) { error = core_output((char *)(uintptr_t)php->p_vaddr, php->p_filesz, offset, ¶ms, tmpbuf); if (error != 0) break; offset += php->p_filesz; php++; } if (error == 0 && params.comp != NULL) error = compressor_flush(params.comp); } if (error) { log(LOG_WARNING, "Failed to write core file for process %s (error %d)\n", curproc->p_comm, error); } done: free(tmpbuf, M_TEMP); if (params.comp != NULL) compressor_fini(params.comp); while ((ninfo = TAILQ_FIRST(¬elst)) != NULL) { TAILQ_REMOVE(¬elst, ninfo, link); free(ninfo, M_TEMP); } if (hdr != NULL) free(hdr, M_TEMP); return (error); } /* * A callback for each_dumpable_segment() to write out the segment's * program header entry. */ static void cb_put_phdr(vm_map_entry_t entry, void *closure) { struct phdr_closure *phc = (struct phdr_closure *)closure; Elf_Phdr *phdr = phc->phdr; phc->offset = round_page(phc->offset); phdr->p_type = PT_LOAD; phdr->p_offset = phc->offset; phdr->p_vaddr = entry->start; phdr->p_paddr = 0; phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; phdr->p_align = PAGE_SIZE; phdr->p_flags = __elfN(untrans_prot)(entry->protection); phc->offset += phdr->p_filesz; phc->phdr++; } /* * A callback for each_dumpable_segment() to gather information about * the number of segments and their total size. */ static void cb_size_segment(vm_map_entry_t entry, void *closure) { struct sseg_closure *ssc = (struct sseg_closure *)closure; ssc->count++; ssc->size += entry->end - entry->start; } /* * For each writable segment in the process's memory map, call the given * function with a pointer to the map entry and some arbitrary * caller-supplied data. */ static void each_dumpable_segment(struct thread *td, segment_callback func, void *closure, int flags) { struct proc *p = td->td_proc; vm_map_t map = &p->p_vmspace->vm_map; vm_map_entry_t entry; vm_object_t backing_object, object; bool ignore_entry; vm_map_lock_read(map); VM_MAP_ENTRY_FOREACH(entry, map) { /* * Don't dump inaccessible mappings, deal with legacy * coredump mode. * * Note that read-only segments related to the elf binary * are marked MAP_ENTRY_NOCOREDUMP now so we no longer * need to arbitrarily ignore such segments. */ if ((flags & SVC_ALL) == 0) { if (elf_legacy_coredump) { if ((entry->protection & VM_PROT_RW) != VM_PROT_RW) continue; } else { if ((entry->protection & VM_PROT_ALL) == 0) continue; } } /* * Dont include memory segment in the coredump if * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in * madvise(2). Do not dump submaps (i.e. parts of the * kernel map). */ if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) continue; if ((entry->eflags & MAP_ENTRY_NOCOREDUMP) != 0 && (flags & SVC_ALL) == 0) continue; if ((object = entry->object.vm_object) == NULL) continue; /* Ignore memory-mapped devices and such things. */ VM_OBJECT_RLOCK(object); while ((backing_object = object->backing_object) != NULL) { VM_OBJECT_RLOCK(backing_object); VM_OBJECT_RUNLOCK(object); object = backing_object; } ignore_entry = (object->flags & OBJ_FICTITIOUS) != 0; VM_OBJECT_RUNLOCK(object); if (ignore_entry) continue; (*func)(entry, closure); } vm_map_unlock_read(map); } /* * Write the core file header to the file, including padding up to * the page boundary. */ static int __elfN(corehdr)(struct coredump_params *p, int numsegs, void *hdr, size_t hdrsize, struct note_info_list *notelst, size_t notesz, int flags) { struct note_info *ninfo; struct sbuf *sb; int error; /* Fill in the header. */ bzero(hdr, hdrsize); __elfN(puthdr)(p->td, hdr, hdrsize, numsegs, notesz, flags); sb = sbuf_new(NULL, NULL, CORE_BUF_SIZE, SBUF_FIXEDLEN); sbuf_set_drain(sb, sbuf_drain_core_output, p); sbuf_start_section(sb, NULL); sbuf_bcat(sb, hdr, hdrsize); TAILQ_FOREACH(ninfo, notelst, link) __elfN(putnote)(ninfo, sb); /* Align up to a page boundary for the program segments. */ sbuf_end_section(sb, -1, PAGE_SIZE, 0); error = sbuf_finish(sb); sbuf_delete(sb); return (error); } static void __elfN(prepare_notes)(struct thread *td, struct note_info_list *list, size_t *sizep) { struct proc *p; struct thread *thr; size_t size; p = td->td_proc; size = 0; size += register_note(list, NT_PRPSINFO, __elfN(note_prpsinfo), p); /* * To have the debugger select the right thread (LWP) as the initial * thread, we dump the state of the thread passed to us in td first. * This is the thread that causes the core dump and thus likely to * be the right thread one wants to have selected in the debugger. */ thr = td; while (thr != NULL) { size += register_note(list, NT_PRSTATUS, __elfN(note_prstatus), thr); size += register_note(list, NT_FPREGSET, __elfN(note_fpregset), thr); size += register_note(list, NT_THRMISC, __elfN(note_thrmisc), thr); size += register_note(list, NT_PTLWPINFO, __elfN(note_ptlwpinfo), thr); size += register_note(list, -1, __elfN(note_threadmd), thr); thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) : TAILQ_NEXT(thr, td_plist); if (thr == td) thr = TAILQ_NEXT(thr, td_plist); } size += register_note(list, NT_PROCSTAT_PROC, __elfN(note_procstat_proc), p); size += register_note(list, NT_PROCSTAT_FILES, note_procstat_files, p); size += register_note(list, NT_PROCSTAT_VMMAP, note_procstat_vmmap, p); size += register_note(list, NT_PROCSTAT_GROUPS, note_procstat_groups, p); size += register_note(list, NT_PROCSTAT_UMASK, note_procstat_umask, p); size += register_note(list, NT_PROCSTAT_RLIMIT, note_procstat_rlimit, p); size += register_note(list, NT_PROCSTAT_OSREL, note_procstat_osrel, p); size += register_note(list, NT_PROCSTAT_PSSTRINGS, __elfN(note_procstat_psstrings), p); size += register_note(list, NT_PROCSTAT_AUXV, __elfN(note_procstat_auxv), p); *sizep = size; } static void __elfN(puthdr)(struct thread *td, void *hdr, size_t hdrsize, int numsegs, size_t notesz, int flags) { Elf_Ehdr *ehdr; Elf_Phdr *phdr; Elf_Shdr *shdr; struct phdr_closure phc; ehdr = (Elf_Ehdr *)hdr; ehdr->e_ident[EI_MAG0] = ELFMAG0; ehdr->e_ident[EI_MAG1] = ELFMAG1; ehdr->e_ident[EI_MAG2] = ELFMAG2; ehdr->e_ident[EI_MAG3] = ELFMAG3; ehdr->e_ident[EI_CLASS] = ELF_CLASS; ehdr->e_ident[EI_DATA] = ELF_DATA; ehdr->e_ident[EI_VERSION] = EV_CURRENT; ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD; ehdr->e_ident[EI_ABIVERSION] = 0; ehdr->e_ident[EI_PAD] = 0; ehdr->e_type = ET_CORE; ehdr->e_machine = td->td_proc->p_elf_machine; ehdr->e_version = EV_CURRENT; ehdr->e_entry = 0; ehdr->e_phoff = sizeof(Elf_Ehdr); ehdr->e_flags = td->td_proc->p_elf_flags; ehdr->e_ehsize = sizeof(Elf_Ehdr); ehdr->e_phentsize = sizeof(Elf_Phdr); ehdr->e_shentsize = sizeof(Elf_Shdr); ehdr->e_shstrndx = SHN_UNDEF; if (numsegs + 1 < PN_XNUM) { ehdr->e_phnum = numsegs + 1; ehdr->e_shnum = 0; } else { ehdr->e_phnum = PN_XNUM; ehdr->e_shnum = 1; ehdr->e_shoff = ehdr->e_phoff + (numsegs + 1) * ehdr->e_phentsize; KASSERT(ehdr->e_shoff == hdrsize - sizeof(Elf_Shdr), ("e_shoff: %zu, hdrsize - shdr: %zu", (size_t)ehdr->e_shoff, hdrsize - sizeof(Elf_Shdr))); shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff); memset(shdr, 0, sizeof(*shdr)); /* * A special first section is used to hold large segment and * section counts. This was proposed by Sun Microsystems in * Solaris and has been adopted by Linux; the standard ELF * tools are already familiar with the technique. * * See table 7-7 of the Solaris "Linker and Libraries Guide" * (or 12-7 depending on the version of the document) for more * details. */ shdr->sh_type = SHT_NULL; shdr->sh_size = ehdr->e_shnum; shdr->sh_link = ehdr->e_shstrndx; shdr->sh_info = numsegs + 1; } /* * Fill in the program header entries. */ phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff); /* The note segement. */ phdr->p_type = PT_NOTE; phdr->p_offset = hdrsize; phdr->p_vaddr = 0; phdr->p_paddr = 0; phdr->p_filesz = notesz; phdr->p_memsz = 0; phdr->p_flags = PF_R; phdr->p_align = ELF_NOTE_ROUNDSIZE; phdr++; /* All the writable segments from the program. */ phc.phdr = phdr; phc.offset = round_page(hdrsize + notesz); each_dumpable_segment(td, cb_put_phdr, &phc, flags); } static size_t register_note(struct note_info_list *list, int type, outfunc_t out, void *arg) { struct note_info *ninfo; size_t size, notesize; size = 0; out(arg, NULL, &size); ninfo = malloc(sizeof(*ninfo), M_TEMP, M_ZERO | M_WAITOK); ninfo->type = type; ninfo->outfunc = out; ninfo->outarg = arg; ninfo->outsize = size; TAILQ_INSERT_TAIL(list, ninfo, link); if (type == -1) return (size); notesize = sizeof(Elf_Note) + /* note header */ roundup2(sizeof(FREEBSD_ABI_VENDOR), ELF_NOTE_ROUNDSIZE) + /* note name */ roundup2(size, ELF_NOTE_ROUNDSIZE); /* note description */ return (notesize); } static size_t append_note_data(const void *src, void *dst, size_t len) { size_t padded_len; padded_len = roundup2(len, ELF_NOTE_ROUNDSIZE); if (dst != NULL) { bcopy(src, dst, len); bzero((char *)dst + len, padded_len - len); } return (padded_len); } size_t __elfN(populate_note)(int type, void *src, void *dst, size_t size, void **descp) { Elf_Note *note; char *buf; size_t notesize; buf = dst; if (buf != NULL) { note = (Elf_Note *)buf; note->n_namesz = sizeof(FREEBSD_ABI_VENDOR); note->n_descsz = size; note->n_type = type; buf += sizeof(*note); buf += append_note_data(FREEBSD_ABI_VENDOR, buf, sizeof(FREEBSD_ABI_VENDOR)); append_note_data(src, buf, size); if (descp != NULL) *descp = buf; } notesize = sizeof(Elf_Note) + /* note header */ roundup2(sizeof(FREEBSD_ABI_VENDOR), ELF_NOTE_ROUNDSIZE) + /* note name */ roundup2(size, ELF_NOTE_ROUNDSIZE); /* note description */ return (notesize); } static void __elfN(putnote)(struct note_info *ninfo, struct sbuf *sb) { Elf_Note note; ssize_t old_len, sect_len; size_t new_len, descsz, i; if (ninfo->type == -1) { ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize); return; } note.n_namesz = sizeof(FREEBSD_ABI_VENDOR); note.n_descsz = ninfo->outsize; note.n_type = ninfo->type; sbuf_bcat(sb, ¬e, sizeof(note)); sbuf_start_section(sb, &old_len); sbuf_bcat(sb, FREEBSD_ABI_VENDOR, sizeof(FREEBSD_ABI_VENDOR)); sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0); if (note.n_descsz == 0) return; sbuf_start_section(sb, &old_len); ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize); sect_len = sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0); if (sect_len < 0) return; new_len = (size_t)sect_len; descsz = roundup(note.n_descsz, ELF_NOTE_ROUNDSIZE); if (new_len < descsz) { /* * It is expected that individual note emitters will correctly * predict their expected output size and fill up to that size * themselves, padding in a format-specific way if needed. * However, in case they don't, just do it here with zeros. */ for (i = 0; i < descsz - new_len; i++) sbuf_putc(sb, 0); } else if (new_len > descsz) { /* * We can't always truncate sb -- we may have drained some * of it already. */ KASSERT(new_len == descsz, ("%s: Note type %u changed as we " "read it (%zu > %zu). Since it is longer than " "expected, this coredump's notes are corrupt. THIS " "IS A BUG in the note_procstat routine for type %u.\n", __func__, (unsigned)note.n_type, new_len, descsz, (unsigned)note.n_type)); } } /* * Miscellaneous note out functions. */ #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 #include #include typedef struct prstatus32 elf_prstatus_t; typedef struct prpsinfo32 elf_prpsinfo_t; typedef struct fpreg32 elf_prfpregset_t; typedef struct fpreg32 elf_fpregset_t; typedef struct reg32 elf_gregset_t; typedef struct thrmisc32 elf_thrmisc_t; #define ELF_KERN_PROC_MASK KERN_PROC_MASK32 typedef struct kinfo_proc32 elf_kinfo_proc_t; typedef uint32_t elf_ps_strings_t; #else typedef prstatus_t elf_prstatus_t; typedef prpsinfo_t elf_prpsinfo_t; typedef prfpregset_t elf_prfpregset_t; typedef prfpregset_t elf_fpregset_t; typedef gregset_t elf_gregset_t; typedef thrmisc_t elf_thrmisc_t; #define ELF_KERN_PROC_MASK 0 typedef struct kinfo_proc elf_kinfo_proc_t; typedef vm_offset_t elf_ps_strings_t; #endif static void __elfN(note_prpsinfo)(void *arg, struct sbuf *sb, size_t *sizep) { struct sbuf sbarg; size_t len; char *cp, *end; struct proc *p; elf_prpsinfo_t *psinfo; int error; p = (struct proc *)arg; if (sb != NULL) { KASSERT(*sizep == sizeof(*psinfo), ("invalid size")); psinfo = malloc(sizeof(*psinfo), M_TEMP, M_ZERO | M_WAITOK); psinfo->pr_version = PRPSINFO_VERSION; psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t); strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname)); PROC_LOCK(p); if (p->p_args != NULL) { len = sizeof(psinfo->pr_psargs) - 1; if (len > p->p_args->ar_length) len = p->p_args->ar_length; memcpy(psinfo->pr_psargs, p->p_args->ar_args, len); PROC_UNLOCK(p); error = 0; } else { _PHOLD(p); PROC_UNLOCK(p); sbuf_new(&sbarg, psinfo->pr_psargs, sizeof(psinfo->pr_psargs), SBUF_FIXEDLEN); error = proc_getargv(curthread, p, &sbarg); PRELE(p); if (sbuf_finish(&sbarg) == 0) len = sbuf_len(&sbarg) - 1; else len = sizeof(psinfo->pr_psargs) - 1; sbuf_delete(&sbarg); } if (error || len == 0) strlcpy(psinfo->pr_psargs, p->p_comm, sizeof(psinfo->pr_psargs)); else { KASSERT(len < sizeof(psinfo->pr_psargs), ("len is too long: %zu vs %zu", len, sizeof(psinfo->pr_psargs))); cp = psinfo->pr_psargs; end = cp + len - 1; for (;;) { cp = memchr(cp, '\0', end - cp); if (cp == NULL) break; *cp = ' '; } } psinfo->pr_pid = p->p_pid; sbuf_bcat(sb, psinfo, sizeof(*psinfo)); free(psinfo, M_TEMP); } *sizep = sizeof(*psinfo); } static void __elfN(note_prstatus)(void *arg, struct sbuf *sb, size_t *sizep) { struct thread *td; elf_prstatus_t *status; td = (struct thread *)arg; if (sb != NULL) { KASSERT(*sizep == sizeof(*status), ("invalid size")); status = malloc(sizeof(*status), M_TEMP, M_ZERO | M_WAITOK); status->pr_version = PRSTATUS_VERSION; status->pr_statussz = sizeof(elf_prstatus_t); status->pr_gregsetsz = sizeof(elf_gregset_t); status->pr_fpregsetsz = sizeof(elf_fpregset_t); status->pr_osreldate = osreldate; status->pr_cursig = td->td_proc->p_sig; status->pr_pid = td->td_tid; #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 fill_regs32(td, &status->pr_reg); #else fill_regs(td, &status->pr_reg); #endif sbuf_bcat(sb, status, sizeof(*status)); free(status, M_TEMP); } *sizep = sizeof(*status); } static void __elfN(note_fpregset)(void *arg, struct sbuf *sb, size_t *sizep) { struct thread *td; elf_prfpregset_t *fpregset; td = (struct thread *)arg; if (sb != NULL) { KASSERT(*sizep == sizeof(*fpregset), ("invalid size")); fpregset = malloc(sizeof(*fpregset), M_TEMP, M_ZERO | M_WAITOK); #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 fill_fpregs32(td, fpregset); #else fill_fpregs(td, fpregset); #endif sbuf_bcat(sb, fpregset, sizeof(*fpregset)); free(fpregset, M_TEMP); } *sizep = sizeof(*fpregset); } static void __elfN(note_thrmisc)(void *arg, struct sbuf *sb, size_t *sizep) { struct thread *td; elf_thrmisc_t thrmisc; td = (struct thread *)arg; if (sb != NULL) { KASSERT(*sizep == sizeof(thrmisc), ("invalid size")); bzero(&thrmisc, sizeof(thrmisc)); strcpy(thrmisc.pr_tname, td->td_name); sbuf_bcat(sb, &thrmisc, sizeof(thrmisc)); } *sizep = sizeof(thrmisc); } static void __elfN(note_ptlwpinfo)(void *arg, struct sbuf *sb, size_t *sizep) { struct thread *td; size_t size; int structsize; #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 struct ptrace_lwpinfo32 pl; #else struct ptrace_lwpinfo pl; #endif td = (struct thread *)arg; size = sizeof(structsize) + sizeof(pl); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(pl); sbuf_bcat(sb, &structsize, sizeof(structsize)); bzero(&pl, sizeof(pl)); pl.pl_lwpid = td->td_tid; pl.pl_event = PL_EVENT_NONE; pl.pl_sigmask = td->td_sigmask; pl.pl_siglist = td->td_siglist; if (td->td_si.si_signo != 0) { pl.pl_event = PL_EVENT_SIGNAL; pl.pl_flags |= PL_FLAG_SI; #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 siginfo_to_siginfo32(&td->td_si, &pl.pl_siginfo); #else pl.pl_siginfo = td->td_si; #endif } strcpy(pl.pl_tdname, td->td_name); /* XXX TODO: supply more information in struct ptrace_lwpinfo*/ sbuf_bcat(sb, &pl, sizeof(pl)); } *sizep = size; } /* * Allow for MD specific notes, as well as any MD * specific preparations for writing MI notes. */ static void __elfN(note_threadmd)(void *arg, struct sbuf *sb, size_t *sizep) { struct thread *td; void *buf; size_t size; td = (struct thread *)arg; size = *sizep; if (size != 0 && sb != NULL) buf = malloc(size, M_TEMP, M_ZERO | M_WAITOK); else buf = NULL; size = 0; __elfN(dump_thread)(td, buf, &size); KASSERT(sb == NULL || *sizep == size, ("invalid size")); if (size != 0 && sb != NULL) sbuf_bcat(sb, buf, size); free(buf, M_TEMP); *sizep = size; } #ifdef KINFO_PROC_SIZE CTASSERT(sizeof(struct kinfo_proc) == KINFO_PROC_SIZE); #endif static void __elfN(note_procstat_proc)(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size; int structsize; p = (struct proc *)arg; size = sizeof(structsize) + p->p_numthreads * sizeof(elf_kinfo_proc_t); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(elf_kinfo_proc_t); sbuf_bcat(sb, &structsize, sizeof(structsize)); sx_slock(&proctree_lock); PROC_LOCK(p); kern_proc_out(p, sb, ELF_KERN_PROC_MASK); sx_sunlock(&proctree_lock); } *sizep = size; } #ifdef KINFO_FILE_SIZE CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); #endif static void note_procstat_files(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size, sect_sz, i; ssize_t start_len, sect_len; int structsize, filedesc_flags; if (coredump_pack_fileinfo) filedesc_flags = KERN_FILEDESC_PACK_KINFO; else filedesc_flags = 0; p = (struct proc *)arg; structsize = sizeof(struct kinfo_file); if (sb == NULL) { size = 0; sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN); sbuf_set_drain(sb, sbuf_count_drain, &size); sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); kern_proc_filedesc_out(p, sb, -1, filedesc_flags); sbuf_finish(sb); sbuf_delete(sb); *sizep = size; } else { sbuf_start_section(sb, &start_len); sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); kern_proc_filedesc_out(p, sb, *sizep - sizeof(structsize), filedesc_flags); sect_len = sbuf_end_section(sb, start_len, 0, 0); if (sect_len < 0) return; sect_sz = sect_len; KASSERT(sect_sz <= *sizep, ("kern_proc_filedesc_out did not respect maxlen; " "requested %zu, got %zu", *sizep - sizeof(structsize), sect_sz - sizeof(structsize))); for (i = 0; i < *sizep - sect_sz && sb->s_error == 0; i++) sbuf_putc(sb, 0); } } #ifdef KINFO_VMENTRY_SIZE CTASSERT(sizeof(struct kinfo_vmentry) == KINFO_VMENTRY_SIZE); #endif static void note_procstat_vmmap(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size; int structsize, vmmap_flags; if (coredump_pack_vmmapinfo) vmmap_flags = KERN_VMMAP_PACK_KINFO; else vmmap_flags = 0; p = (struct proc *)arg; structsize = sizeof(struct kinfo_vmentry); if (sb == NULL) { size = 0; sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN); sbuf_set_drain(sb, sbuf_count_drain, &size); sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); kern_proc_vmmap_out(p, sb, -1, vmmap_flags); sbuf_finish(sb); sbuf_delete(sb); *sizep = size; } else { sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); kern_proc_vmmap_out(p, sb, *sizep - sizeof(structsize), vmmap_flags); } } static void note_procstat_groups(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size; int structsize; p = (struct proc *)arg; size = sizeof(structsize) + p->p_ucred->cr_ngroups * sizeof(gid_t); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(gid_t); sbuf_bcat(sb, &structsize, sizeof(structsize)); sbuf_bcat(sb, p->p_ucred->cr_groups, p->p_ucred->cr_ngroups * sizeof(gid_t)); } *sizep = size; } static void note_procstat_umask(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size; int structsize; p = (struct proc *)arg; size = sizeof(structsize) + sizeof(p->p_pd->pd_cmask); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(p->p_pd->pd_cmask); sbuf_bcat(sb, &structsize, sizeof(structsize)); sbuf_bcat(sb, &p->p_pd->pd_cmask, sizeof(p->p_pd->pd_cmask)); } *sizep = size; } static void note_procstat_rlimit(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; struct rlimit rlim[RLIM_NLIMITS]; size_t size; int structsize, i; p = (struct proc *)arg; size = sizeof(structsize) + sizeof(rlim); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(rlim); sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); for (i = 0; i < RLIM_NLIMITS; i++) lim_rlimit_proc(p, i, &rlim[i]); PROC_UNLOCK(p); sbuf_bcat(sb, rlim, sizeof(rlim)); } *sizep = size; } static void note_procstat_osrel(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size; int structsize; p = (struct proc *)arg; size = sizeof(structsize) + sizeof(p->p_osrel); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(p->p_osrel); sbuf_bcat(sb, &structsize, sizeof(structsize)); sbuf_bcat(sb, &p->p_osrel, sizeof(p->p_osrel)); } *sizep = size; } static void __elfN(note_procstat_psstrings)(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; elf_ps_strings_t ps_strings; size_t size; int structsize; p = (struct proc *)arg; size = sizeof(structsize) + sizeof(ps_strings); if (sb != NULL) { KASSERT(*sizep == size, ("invalid size")); structsize = sizeof(ps_strings); #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 ps_strings = PTROUT(p->p_sysent->sv_psstrings); #else ps_strings = p->p_sysent->sv_psstrings; #endif sbuf_bcat(sb, &structsize, sizeof(structsize)); sbuf_bcat(sb, &ps_strings, sizeof(ps_strings)); } *sizep = size; } static void __elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep) { struct proc *p; size_t size; int structsize; p = (struct proc *)arg; if (sb == NULL) { size = 0; sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN); sbuf_set_drain(sb, sbuf_count_drain, &size); sbuf_bcat(sb, &structsize, sizeof(structsize)); PHOLD(p); proc_getauxv(curthread, p, sb); PRELE(p); sbuf_finish(sb); sbuf_delete(sb); *sizep = size; } else { structsize = sizeof(Elf_Auxinfo); sbuf_bcat(sb, &structsize, sizeof(structsize)); PHOLD(p); proc_getauxv(curthread, p, sb); PRELE(p); } } static boolean_t __elfN(parse_notes)(struct image_params *imgp, Elf_Note *checknote, const char *note_vendor, const Elf_Phdr *pnote, boolean_t (*cb)(const Elf_Note *, void *, boolean_t *), void *cb_arg) { const Elf_Note *note, *note0, *note_end; const char *note_name; char *buf; int i, error; boolean_t res; /* We need some limit, might as well use PAGE_SIZE. */ if (pnote == NULL || pnote->p_filesz > PAGE_SIZE) return (FALSE); ASSERT_VOP_LOCKED(imgp->vp, "parse_notes"); if (pnote->p_offset > PAGE_SIZE || pnote->p_filesz > PAGE_SIZE - pnote->p_offset) { buf = malloc(pnote->p_filesz, M_TEMP, M_NOWAIT); if (buf == NULL) { VOP_UNLOCK(imgp->vp); buf = malloc(pnote->p_filesz, M_TEMP, M_WAITOK); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); } error = vn_rdwr(UIO_READ, imgp->vp, buf, pnote->p_filesz, pnote->p_offset, UIO_SYSSPACE, IO_NODELOCKED, curthread->td_ucred, NOCRED, NULL, curthread); if (error != 0) { uprintf("i/o error PT_NOTE\n"); goto retf; } note = note0 = (const Elf_Note *)buf; note_end = (const Elf_Note *)(buf + pnote->p_filesz); } else { note = note0 = (const Elf_Note *)(imgp->image_header + pnote->p_offset); note_end = (const Elf_Note *)(imgp->image_header + pnote->p_offset + pnote->p_filesz); buf = NULL; } for (i = 0; i < 100 && note >= note0 && note < note_end; i++) { if (!aligned(note, Elf32_Addr) || (const char *)note_end - (const char *)note < sizeof(Elf_Note)) { goto retf; } if (note->n_namesz != checknote->n_namesz || note->n_descsz != checknote->n_descsz || note->n_type != checknote->n_type) goto nextnote; note_name = (const char *)(note + 1); if (note_name + checknote->n_namesz >= (const char *)note_end || strncmp(note_vendor, note_name, checknote->n_namesz) != 0) goto nextnote; if (cb(note, cb_arg, &res)) goto ret; nextnote: note = (const Elf_Note *)((const char *)(note + 1) + roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) + roundup2(note->n_descsz, ELF_NOTE_ROUNDSIZE)); } retf: res = FALSE; ret: free(buf, M_TEMP); return (res); } struct brandnote_cb_arg { Elf_Brandnote *brandnote; int32_t *osrel; }; static boolean_t brandnote_cb(const Elf_Note *note, void *arg0, boolean_t *res) { struct brandnote_cb_arg *arg; arg = arg0; /* * Fetch the osreldate for binary from the ELF OSABI-note if * necessary. */ *res = (arg->brandnote->flags & BN_TRANSLATE_OSREL) != 0 && arg->brandnote->trans_osrel != NULL ? arg->brandnote->trans_osrel(note, arg->osrel) : TRUE; return (TRUE); } static Elf_Note fctl_note = { .n_namesz = sizeof(FREEBSD_ABI_VENDOR), .n_descsz = sizeof(uint32_t), .n_type = NT_FREEBSD_FEATURE_CTL, }; struct fctl_cb_arg { boolean_t *has_fctl0; uint32_t *fctl0; }; static boolean_t note_fctl_cb(const Elf_Note *note, void *arg0, boolean_t *res) { struct fctl_cb_arg *arg; const Elf32_Word *desc; uintptr_t p; arg = arg0; p = (uintptr_t)(note + 1); p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE); desc = (const Elf32_Word *)p; *arg->has_fctl0 = TRUE; *arg->fctl0 = desc[0]; *res = TRUE; return (TRUE); } /* * Try to find the appropriate ABI-note section for checknote, fetch * the osreldate and feature control flags for binary from the ELF * OSABI-note. Only the first page of the image is searched, the same * as for headers. */ static boolean_t __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *brandnote, int32_t *osrel, boolean_t *has_fctl0, uint32_t *fctl0) { const Elf_Phdr *phdr; const Elf_Ehdr *hdr; struct brandnote_cb_arg b_arg; struct fctl_cb_arg f_arg; int i, j; hdr = (const Elf_Ehdr *)imgp->image_header; phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); b_arg.brandnote = brandnote; b_arg.osrel = osrel; f_arg.has_fctl0 = has_fctl0; f_arg.fctl0 = fctl0; for (i = 0; i < hdr->e_phnum; i++) { if (phdr[i].p_type == PT_NOTE && __elfN(parse_notes)(imgp, &brandnote->hdr, brandnote->vendor, &phdr[i], brandnote_cb, &b_arg)) { for (j = 0; j < hdr->e_phnum; j++) { if (phdr[j].p_type == PT_NOTE && __elfN(parse_notes)(imgp, &fctl_note, FREEBSD_ABI_VENDOR, &phdr[j], note_fctl_cb, &f_arg)) break; } return (TRUE); } } return (FALSE); } /* * Tell kern_execve.c about it, with a little help from the linker. */ static struct execsw __elfN(execsw) = { .ex_imgact = __CONCAT(exec_, __elfN(imgact)), .ex_name = __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) }; EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw)); static vm_prot_t __elfN(trans_prot)(Elf_Word flags) { vm_prot_t prot; prot = 0; if (flags & PF_X) prot |= VM_PROT_EXECUTE; if (flags & PF_W) prot |= VM_PROT_WRITE; if (flags & PF_R) prot |= VM_PROT_READ; #if __ELF_WORD_SIZE == 32 && (defined(__amd64__) || defined(__i386__)) if (i386_read_exec && (flags & PF_R)) prot |= VM_PROT_EXECUTE; #endif return (prot); } static Elf_Word __elfN(untrans_prot)(vm_prot_t prot) { Elf_Word flags; flags = 0; if (prot & VM_PROT_EXECUTE) flags |= PF_X; if (prot & VM_PROT_READ) flags |= PF_R; if (prot & VM_PROT_WRITE) flags |= PF_W; return (flags); } void __elfN(stackgap)(struct image_params *imgp, uintptr_t *stack_base) { uintptr_t range, rbase, gap; int pct; pct = __elfN(aslr_stack_gap); if (pct == 0) return; if (pct > 50) pct = 50; range = imgp->eff_stack_sz * pct / 100; arc4rand(&rbase, sizeof(rbase), 0); gap = rbase % range; gap &= ~(sizeof(u_long) - 1); *stack_base -= gap; } diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c index 0611eedcec73..2ea0efc4a2cb 100644 --- a/sys/kern/kern_exec.c +++ b/sys/kern/kern_exec.c @@ -1,1878 +1,1883 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 1993, David Greenman * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_hwpmc_hooks.h" #include "opt_ktrace.h" #include "opt_vm.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include #include #include #include #include #include #ifdef HWPMC_HOOKS #include #endif #include #include #include #ifdef KDTRACE_HOOKS #include dtrace_execexit_func_t dtrace_fasttrap_exec; #endif SDT_PROVIDER_DECLARE(proc); SDT_PROBE_DEFINE1(proc, , , exec, "char *"); SDT_PROBE_DEFINE1(proc, , , exec__failure, "int"); SDT_PROBE_DEFINE1(proc, , , exec__success, "char *"); MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments"); int coredump_pack_fileinfo = 1; SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN, &coredump_pack_fileinfo, 0, "Enable file path packing in 'procstat -f' coredump notes"); int coredump_pack_vmmapinfo = 1; SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN, &coredump_pack_vmmapinfo, 0, "Enable file path packing in 'procstat -v' coredump notes"); static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS); static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS); static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS); static int do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, struct vmspace *oldvmspace); /* XXX This should be vm_size_t. */ SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD| CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", "Location of process' ps_strings structure"); /* XXX This should be vm_size_t. */ SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD| CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", "Top of process stack"); SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_stackprot, "I", "Stack memory permissions"); u_long ps_arg_cache_limit = PAGE_SIZE / 16; SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, &ps_arg_cache_limit, 0, "Process' command line characters cache limit"); static int disallow_high_osrel; SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, &disallow_high_osrel, 0, "Disallow execution of binaries built for higher version of the world"); static int map_at_zero = 0; SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0, "Permit processes to map an object at virtual address 0."); +int core_dump_can_intr = 1; +SYSCTL_INT(_kern, OID_AUTO, core_dump_can_intr, CTLFLAG_RWTUN, + &core_dump_can_intr, 0, + "Core dumping interruptible with SIGKILL"); + static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS) { struct proc *p; int error; p = curproc; #ifdef SCTL_MASK32 if (req->flags & SCTL_MASK32) { unsigned int val; val = (unsigned int)p->p_sysent->sv_psstrings; error = SYSCTL_OUT(req, &val, sizeof(val)); } else #endif error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings, sizeof(p->p_sysent->sv_psstrings)); return error; } static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS) { struct proc *p; int error; p = curproc; #ifdef SCTL_MASK32 if (req->flags & SCTL_MASK32) { unsigned int val; val = (unsigned int)p->p_sysent->sv_usrstack; error = SYSCTL_OUT(req, &val, sizeof(val)); } else #endif error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack, sizeof(p->p_sysent->sv_usrstack)); return error; } static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS) { struct proc *p; p = curproc; return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot, sizeof(p->p_sysent->sv_stackprot))); } /* * Each of the items is a pointer to a `const struct execsw', hence the * double pointer here. */ static const struct execsw **execsw; #ifndef _SYS_SYSPROTO_H_ struct execve_args { char *fname; char **argv; char **envv; }; #endif int sys_execve(struct thread *td, struct execve_args *uap) { struct image_args args; struct vmspace *oldvmspace; int error; error = pre_execve(td, &oldvmspace); if (error != 0) return (error); error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, uap->argv, uap->envv); if (error == 0) error = kern_execve(td, &args, NULL, oldvmspace); post_execve(td, error, oldvmspace); AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); return (error); } #ifndef _SYS_SYSPROTO_H_ struct fexecve_args { int fd; char **argv; char **envv; }; #endif int sys_fexecve(struct thread *td, struct fexecve_args *uap) { struct image_args args; struct vmspace *oldvmspace; int error; error = pre_execve(td, &oldvmspace); if (error != 0) return (error); error = exec_copyin_args(&args, NULL, UIO_SYSSPACE, uap->argv, uap->envv); if (error == 0) { args.fd = uap->fd; error = kern_execve(td, &args, NULL, oldvmspace); } post_execve(td, error, oldvmspace); AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); return (error); } #ifndef _SYS_SYSPROTO_H_ struct __mac_execve_args { char *fname; char **argv; char **envv; struct mac *mac_p; }; #endif int sys___mac_execve(struct thread *td, struct __mac_execve_args *uap) { #ifdef MAC struct image_args args; struct vmspace *oldvmspace; int error; error = pre_execve(td, &oldvmspace); if (error != 0) return (error); error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, uap->argv, uap->envv); if (error == 0) error = kern_execve(td, &args, uap->mac_p, oldvmspace); post_execve(td, error, oldvmspace); AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); return (error); #else return (ENOSYS); #endif } int pre_execve(struct thread *td, struct vmspace **oldvmspace) { struct proc *p; int error; KASSERT(td == curthread, ("non-current thread %p", td)); error = 0; p = td->td_proc; if ((p->p_flag & P_HADTHREADS) != 0) { PROC_LOCK(p); if (thread_single(p, SINGLE_BOUNDARY) != 0) error = ERESTART; PROC_UNLOCK(p); } KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0, ("nested execve")); *oldvmspace = p->p_vmspace; return (error); } void post_execve(struct thread *td, int error, struct vmspace *oldvmspace) { struct proc *p; KASSERT(td == curthread, ("non-current thread %p", td)); p = td->td_proc; if ((p->p_flag & P_HADTHREADS) != 0) { PROC_LOCK(p); /* * If success, we upgrade to SINGLE_EXIT state to * force other threads to suicide. */ if (error == EJUSTRETURN) thread_single(p, SINGLE_EXIT); else thread_single_end(p, SINGLE_BOUNDARY); PROC_UNLOCK(p); } exec_cleanup(td, oldvmspace); } /* * kern_execve() has the astonishing property of not always returning to * the caller. If sufficiently bad things happen during the call to * do_execve(), it can end up calling exit1(); as a result, callers must * avoid doing anything which they might need to undo (e.g., allocating * memory). */ int kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p, struct vmspace *oldvmspace) { AUDIT_ARG_ARGV(args->begin_argv, args->argc, exec_args_get_begin_envv(args) - args->begin_argv); AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc, args->endp - exec_args_get_begin_envv(args)); return (do_execve(td, args, mac_p, oldvmspace)); } static void execve_nosetid(struct image_params *imgp) { imgp->credential_setid = false; if (imgp->newcred != NULL) { crfree(imgp->newcred); imgp->newcred = NULL; } } /* * In-kernel implementation of execve(). All arguments are assumed to be * userspace pointers from the passed thread. */ static int do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, struct vmspace *oldvmspace) { struct proc *p = td->td_proc; struct nameidata nd; struct ucred *oldcred; struct uidinfo *euip = NULL; uintptr_t stack_base; struct image_params image_params, *imgp; struct vattr attr; int (*img_first)(struct image_params *); struct pargs *oldargs = NULL, *newargs = NULL; struct sigacts *oldsigacts = NULL, *newsigacts = NULL; #ifdef KTRACE struct ktr_io_params *kiop; #endif struct vnode *oldtextvp = NULL, *newtextvp; int credential_changing; #ifdef MAC struct label *interpvplabel = NULL; int will_transition; #endif #ifdef HWPMC_HOOKS struct pmckern_procexec pe; #endif int error, i, orig_osrel; uint32_t orig_fctl0; static const char fexecv_proc_title[] = "(fexecv)"; imgp = &image_params; #ifdef KTRACE kiop = NULL; #endif /* * Lock the process and set the P_INEXEC flag to indicate that * it should be left alone until we're done here. This is * necessary to avoid race conditions - e.g. in ptrace() - * that might allow a local user to illicitly obtain elevated * privileges. */ PROC_LOCK(p); KASSERT((p->p_flag & P_INEXEC) == 0, ("%s(): process already has P_INEXEC flag", __func__)); p->p_flag |= P_INEXEC; PROC_UNLOCK(p); /* * Initialize part of the common data */ bzero(imgp, sizeof(*imgp)); imgp->proc = p; imgp->attr = &attr; imgp->args = args; oldcred = p->p_ucred; orig_osrel = p->p_osrel; orig_fctl0 = p->p_fctl0; #ifdef MAC error = mac_execve_enter(imgp, mac_p); if (error) goto exec_fail; #endif /* * Translate the file name. namei() returns a vnode pointer * in ni_vp among other things. * * XXXAUDIT: It would be desirable to also audit the name of the * interpreter if this is an interpreted binary. */ if (args->fname != NULL) { NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | SAVENAME | AUDITVNODE1, UIO_SYSSPACE, args->fname, td); } SDT_PROBE1(proc, , , exec, args->fname); interpret: if (args->fname != NULL) { #ifdef CAPABILITY_MODE /* * While capability mode can't reach this point via direct * path arguments to execve(), we also don't allow * interpreters to be used in capability mode (for now). * Catch indirect lookups and return a permissions error. */ if (IN_CAPABILITY_MODE(td)) { error = ECAPMODE; goto exec_fail; } #endif error = namei(&nd); if (error) goto exec_fail; newtextvp = nd.ni_vp; imgp->vp = newtextvp; } else { AUDIT_ARG_FD(args->fd); /* * Descriptors opened only with O_EXEC or O_RDONLY are allowed. */ error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, &newtextvp); if (error) goto exec_fail; vn_lock(newtextvp, LK_SHARED | LK_RETRY); AUDIT_ARG_VNODE1(newtextvp); imgp->vp = newtextvp; } /* * Check file permissions. Also 'opens' file and sets its vnode to * text mode. */ error = exec_check_permissions(imgp); if (error) goto exec_fail_dealloc; imgp->object = imgp->vp->v_object; if (imgp->object != NULL) vm_object_reference(imgp->object); error = exec_map_first_page(imgp); if (error) goto exec_fail_dealloc; imgp->proc->p_osrel = 0; imgp->proc->p_fctl0 = 0; /* * Implement image setuid/setgid. * * Determine new credentials before attempting image activators * so that it can be used by process_exec handlers to determine * credential/setid changes. * * Don't honor setuid/setgid if the filesystem prohibits it or if * the process is being traced. * * We disable setuid/setgid/etc in capability mode on the basis * that most setugid applications are not written with that * environment in mind, and will therefore almost certainly operate * incorrectly. In principle there's no reason that setugid * applications might not be useful in capability mode, so we may want * to reconsider this conservative design choice in the future. * * XXXMAC: For the time being, use NOSUID to also prohibit * transitions on the file system. */ credential_changing = 0; credential_changing |= (attr.va_mode & S_ISUID) && oldcred->cr_uid != attr.va_uid; credential_changing |= (attr.va_mode & S_ISGID) && oldcred->cr_gid != attr.va_gid; #ifdef MAC will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, interpvplabel, imgp); credential_changing |= will_transition; #endif /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ if (credential_changing) imgp->proc->p_pdeathsig = 0; if (credential_changing && #ifdef CAPABILITY_MODE ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && #endif (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && (p->p_flag & P_TRACED) == 0) { imgp->credential_setid = true; VOP_UNLOCK(imgp->vp); imgp->newcred = crdup(oldcred); if (attr.va_mode & S_ISUID) { euip = uifind(attr.va_uid); change_euid(imgp->newcred, euip); } vn_lock(imgp->vp, LK_SHARED | LK_RETRY); if (attr.va_mode & S_ISGID) change_egid(imgp->newcred, attr.va_gid); /* * Implement correct POSIX saved-id behavior. * * XXXMAC: Note that the current logic will save the * uid and gid if a MAC domain transition occurs, even * though maybe it shouldn't. */ change_svuid(imgp->newcred, imgp->newcred->cr_uid); change_svgid(imgp->newcred, imgp->newcred->cr_gid); } else { /* * Implement correct POSIX saved-id behavior. * * XXX: It's not clear that the existing behavior is * POSIX-compliant. A number of sources indicate that the * saved uid/gid should only be updated if the new ruid is * not equal to the old ruid, or the new euid is not equal * to the old euid and the new euid is not equal to the old * ruid. The FreeBSD code always updates the saved uid/gid. * Also, this code uses the new (replaced) euid and egid as * the source, which may or may not be the right ones to use. */ if (oldcred->cr_svuid != oldcred->cr_uid || oldcred->cr_svgid != oldcred->cr_gid) { VOP_UNLOCK(imgp->vp); imgp->newcred = crdup(oldcred); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); change_svuid(imgp->newcred, imgp->newcred->cr_uid); change_svgid(imgp->newcred, imgp->newcred->cr_gid); } } /* The new credentials are installed into the process later. */ /* * Do the best to calculate the full path to the image file. */ if (args->fname != NULL && args->fname[0] == '/') imgp->execpath = args->fname; else { VOP_UNLOCK(imgp->vp); if (vn_fullpath(imgp->vp, &imgp->execpath, &imgp->freepath) != 0) imgp->execpath = args->fname; vn_lock(imgp->vp, LK_SHARED | LK_RETRY); } /* * If the current process has a special image activator it * wants to try first, call it. For example, emulating shell * scripts differently. */ error = -1; if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL) error = img_first(imgp); /* * Loop through the list of image activators, calling each one. * An activator returns -1 if there is no match, 0 on success, * and an error otherwise. */ for (i = 0; error == -1 && execsw[i]; ++i) { if (execsw[i]->ex_imgact == NULL || execsw[i]->ex_imgact == img_first) { continue; } error = (*execsw[i]->ex_imgact)(imgp); } if (error) { if (error == -1) error = ENOEXEC; goto exec_fail_dealloc; } /* * Special interpreter operation, cleanup and loop up to try to * activate the interpreter. */ if (imgp->interpreted) { exec_unmap_first_page(imgp); /* * The text reference needs to be removed for scripts. * There is a short period before we determine that * something is a script where text reference is active. * The vnode lock is held over this entire period * so nothing should illegitimately be blocked. */ MPASS(imgp->textset); VOP_UNSET_TEXT_CHECKED(newtextvp); imgp->textset = false; /* free name buffer and old vnode */ if (args->fname != NULL) NDFREE(&nd, NDF_ONLY_PNBUF); #ifdef MAC mac_execve_interpreter_enter(newtextvp, &interpvplabel); #endif if (imgp->opened) { VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); imgp->opened = 0; } vput(newtextvp); vm_object_deallocate(imgp->object); imgp->object = NULL; execve_nosetid(imgp); imgp->execpath = NULL; free(imgp->freepath, M_TEMP); imgp->freepath = NULL; /* set new name to that of the interpreter */ NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | SAVENAME, UIO_SYSSPACE, imgp->interpreter_name, td); args->fname = imgp->interpreter_name; goto interpret; } /* * NB: We unlock the vnode here because it is believed that none * of the sv_copyout_strings/sv_fixup operations require the vnode. */ VOP_UNLOCK(imgp->vp); if (disallow_high_osrel && P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { error = ENOEXEC; uprintf("Osrel %d for image %s too high\n", p->p_osrel, imgp->execpath != NULL ? imgp->execpath : ""); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); goto exec_fail_dealloc; } /* ABI enforces the use of Capsicum. Switch into capabilities mode. */ if (SV_PROC_FLAG(p, SV_CAPSICUM)) sys_cap_enter(td, NULL); /* * Copy out strings (args and env) and initialize stack base. */ error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); if (error != 0) { vn_lock(imgp->vp, LK_SHARED | LK_RETRY); goto exec_fail_dealloc; } /* * Stack setup. */ error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); if (error != 0) { vn_lock(imgp->vp, LK_SHARED | LK_RETRY); goto exec_fail_dealloc; } if (args->fdp != NULL) { /* Install a brand new file descriptor table. */ fdinstall_remapped(td, args->fdp); args->fdp = NULL; } else { /* * Keep on using the existing file descriptor table. For * security and other reasons, the file descriptor table * cannot be shared after an exec. */ fdunshare(td); pdunshare(td); /* close files on exec */ fdcloseexec(td); } /* * Malloc things before we need locks. */ i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; /* Cache arguments if they fit inside our allowance */ if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { newargs = pargs_alloc(i); bcopy(imgp->args->begin_argv, newargs->ar_args, i); } /* * For security and other reasons, signal handlers cannot * be shared after an exec. The new process gets a copy of the old * handlers. In execsigs(), the new process will have its signals * reset. */ if (sigacts_shared(p->p_sigacts)) { oldsigacts = p->p_sigacts; newsigacts = sigacts_alloc(); sigacts_copy(newsigacts, oldsigacts); } vn_lock(imgp->vp, LK_SHARED | LK_RETRY); PROC_LOCK(p); if (oldsigacts) p->p_sigacts = newsigacts; /* Stop profiling */ stopprofclock(p); /* reset caught signals */ execsigs(p); /* name this process - nameiexec(p, ndp) */ bzero(p->p_comm, sizeof(p->p_comm)); if (args->fname) bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); #ifdef KTR sched_clear_tdname(td); #endif /* * mark as execed, wakeup the process that vforked (if any) and tell * it that it now has its own resources back */ p->p_flag |= P_EXEC; if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) p->p_flag2 &= ~P2_NOTRACE; if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) p->p_flag2 &= ~P2_STKGAP_DISABLE; if (p->p_flag & P_PPWAIT) { p->p_flag &= ~(P_PPWAIT | P_PPTRACE); cv_broadcast(&p->p_pwait); /* STOPs are no longer ignored, arrange for AST */ signotify(td); } if ((imgp->sysent->sv_setid_allowed != NULL && !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) execve_nosetid(imgp); /* * Implement image setuid/setgid installation. */ if (imgp->credential_setid) { /* * Turn off syscall tracing for set-id programs, except for * root. Record any set-id flags first to make sure that * we do not regain any tracing during a possible block. */ setsugid(p); #ifdef KTRACE kiop = ktrprocexec(p); #endif /* * Close any file descriptors 0..2 that reference procfs, * then make sure file descriptors 0..2 are in use. * * Both fdsetugidsafety() and fdcheckstd() may call functions * taking sleepable locks, so temporarily drop our locks. */ PROC_UNLOCK(p); VOP_UNLOCK(imgp->vp); fdsetugidsafety(td); error = fdcheckstd(td); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); if (error != 0) goto exec_fail_dealloc; PROC_LOCK(p); #ifdef MAC if (will_transition) { mac_vnode_execve_transition(oldcred, imgp->newcred, imgp->vp, interpvplabel, imgp); } #endif } else { if (oldcred->cr_uid == oldcred->cr_ruid && oldcred->cr_gid == oldcred->cr_rgid) p->p_flag &= ~P_SUGID; } /* * Set the new credentials. */ if (imgp->newcred != NULL) { proc_set_cred(p, imgp->newcred); crfree(oldcred); oldcred = NULL; } /* * Store the vp for use in procfs. This vnode was referenced by namei * or fgetvp_exec. */ oldtextvp = p->p_textvp; p->p_textvp = newtextvp; #ifdef KDTRACE_HOOKS /* * Tell the DTrace fasttrap provider about the exec if it * has declared an interest. */ if (dtrace_fasttrap_exec) dtrace_fasttrap_exec(p); #endif /* * Notify others that we exec'd, and clear the P_INEXEC flag * as we're now a bona fide freshly-execed process. */ KNOTE_LOCKED(p->p_klist, NOTE_EXEC); p->p_flag &= ~P_INEXEC; /* clear "fork but no exec" flag, as we _are_ execing */ p->p_acflag &= ~AFORK; /* * Free any previous argument cache and replace it with * the new argument cache, if any. */ oldargs = p->p_args; p->p_args = newargs; newargs = NULL; PROC_UNLOCK(p); #ifdef HWPMC_HOOKS /* * Check if system-wide sampling is in effect or if the * current process is using PMCs. If so, do exec() time * processing. This processing needs to happen AFTER the * P_INEXEC flag is cleared. */ if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { VOP_UNLOCK(imgp->vp); pe.pm_credentialschanged = credential_changing; pe.pm_entryaddr = imgp->entry_addr; PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); } #endif /* Set values passed into the program in registers. */ (*p->p_sysent->sv_setregs)(td, imgp, stack_base); VOP_MMAPPED(imgp->vp); SDT_PROBE1(proc, , , exec__success, args->fname); exec_fail_dealloc: if (error != 0) { p->p_osrel = orig_osrel; p->p_fctl0 = orig_fctl0; } if (imgp->firstpage != NULL) exec_unmap_first_page(imgp); if (imgp->vp != NULL) { if (args->fname) NDFREE(&nd, NDF_ONLY_PNBUF); if (imgp->opened) VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); if (imgp->textset) VOP_UNSET_TEXT_CHECKED(imgp->vp); if (error != 0) vput(imgp->vp); else VOP_UNLOCK(imgp->vp); } if (imgp->object != NULL) vm_object_deallocate(imgp->object); free(imgp->freepath, M_TEMP); if (error == 0) { if (p->p_ptevents & PTRACE_EXEC) { PROC_LOCK(p); if (p->p_ptevents & PTRACE_EXEC) td->td_dbgflags |= TDB_EXEC; PROC_UNLOCK(p); } } else { exec_fail: /* we're done here, clear P_INEXEC */ PROC_LOCK(p); p->p_flag &= ~P_INEXEC; PROC_UNLOCK(p); SDT_PROBE1(proc, , , exec__failure, error); } if (imgp->newcred != NULL && oldcred != NULL) crfree(imgp->newcred); #ifdef MAC mac_execve_exit(imgp); mac_execve_interpreter_exit(interpvplabel); #endif exec_free_args(args); /* * Handle deferred decrement of ref counts. */ if (oldtextvp != NULL) vrele(oldtextvp); #ifdef KTRACE ktr_io_params_free(kiop); #endif pargs_drop(oldargs); pargs_drop(newargs); if (oldsigacts != NULL) sigacts_free(oldsigacts); if (euip != NULL) uifree(euip); if (error && imgp->vmspace_destroyed) { /* sorry, no more process anymore. exit gracefully */ exec_cleanup(td, oldvmspace); exit1(td, 0, SIGABRT); /* NOT REACHED */ } #ifdef KTRACE if (error == 0) ktrprocctor(p); #endif /* * We don't want cpu_set_syscall_retval() to overwrite any of * the register values put in place by exec_setregs(). * Implementations of cpu_set_syscall_retval() will leave * registers unmodified when returning EJUSTRETURN. */ return (error == 0 ? EJUSTRETURN : error); } void exec_cleanup(struct thread *td, struct vmspace *oldvmspace) { if ((td->td_pflags & TDP_EXECVMSPC) != 0) { KASSERT(td->td_proc->p_vmspace != oldvmspace, ("oldvmspace still used")); vmspace_free(oldvmspace); td->td_pflags &= ~TDP_EXECVMSPC; } } int exec_map_first_page(struct image_params *imgp) { vm_object_t object; vm_page_t m; int error; if (imgp->firstpage != NULL) exec_unmap_first_page(imgp); object = imgp->vp->v_object; if (object == NULL) return (EACCES); #if VM_NRESERVLEVEL > 0 if ((object->flags & OBJ_COLORED) == 0) { VM_OBJECT_WLOCK(object); vm_object_color(object, 0); VM_OBJECT_WUNLOCK(object); } #endif error = vm_page_grab_valid_unlocked(&m, object, 0, VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); if (error != VM_PAGER_OK) return (EIO); imgp->firstpage = sf_buf_alloc(m, 0); imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); return (0); } void exec_unmap_first_page(struct image_params *imgp) { vm_page_t m; if (imgp->firstpage != NULL) { m = sf_buf_page(imgp->firstpage); sf_buf_free(imgp->firstpage); imgp->firstpage = NULL; vm_page_unwire(m, PQ_ACTIVE); } } void exec_onexec_old(struct thread *td) { sigfastblock_clear(td); umtx_exec(td->td_proc); } /* * Destroy old address space, and allocate a new stack. * The new stack is only sgrowsiz large because it is grown * automatically on a page fault. */ int exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) { int error; struct proc *p = imgp->proc; struct vmspace *vmspace = p->p_vmspace; struct thread *td = curthread; vm_object_t obj; struct rlimit rlim_stack; vm_offset_t sv_minuser, stack_addr; vm_map_t map; vm_prot_t stack_prot; u_long ssiz; imgp->vmspace_destroyed = 1; imgp->sysent = sv; if (p->p_sysent->sv_onexec_old != NULL) p->p_sysent->sv_onexec_old(td); itimers_exec(p); if (sv->sv_onexec != NULL) sv->sv_onexec(p, imgp); EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); /* * Blow away entire process VM, if address space not shared, * otherwise, create a new VM space so that other threads are * not disrupted */ map = &vmspace->vm_map; if (map_at_zero) sv_minuser = sv->sv_minuser; else sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); if (refcount_load(&vmspace->vm_refcnt) == 1 && vm_map_min(map) == sv_minuser && vm_map_max(map) == sv->sv_maxuser && cpu_exec_vmspace_reuse(p, map)) { shmexit(vmspace); pmap_remove_pages(vmspace_pmap(vmspace)); vm_map_remove(map, vm_map_min(map), vm_map_max(map)); /* * An exec terminates mlockall(MCL_FUTURE). * ASLR and W^X states must be re-evaluated. */ vm_map_lock(map); vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | MAP_ASLR_IGNSTART | MAP_WXORX); vm_map_unlock(map); } else { error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); if (error) return (error); vmspace = p->p_vmspace; map = &vmspace->vm_map; } map->flags |= imgp->map_flags; /* Map a shared page */ obj = sv->sv_shared_page_obj; if (obj != NULL) { vm_object_reference(obj); error = vm_map_fixed(map, obj, 0, sv->sv_shared_page_base, sv->sv_shared_page_len, VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_READ | VM_PROT_EXECUTE, MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); if (error != KERN_SUCCESS) { vm_object_deallocate(obj); return (vm_mmap_to_errno(error)); } } /* Allocate a new stack */ if (imgp->stack_sz != 0) { ssiz = trunc_page(imgp->stack_sz); PROC_LOCK(p); lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); PROC_UNLOCK(p); if (ssiz > rlim_stack.rlim_max) ssiz = rlim_stack.rlim_max; if (ssiz > rlim_stack.rlim_cur) { rlim_stack.rlim_cur = ssiz; kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); } } else if (sv->sv_maxssiz != NULL) { ssiz = *sv->sv_maxssiz; } else { ssiz = maxssiz; } imgp->eff_stack_sz = lim_cur(curthread, RLIMIT_STACK); if (ssiz < imgp->eff_stack_sz) imgp->eff_stack_sz = ssiz; stack_addr = sv->sv_usrstack - ssiz; stack_prot = obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot : sv->sv_stackprot; error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz, stack_prot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN); if (error != KERN_SUCCESS) { uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " "failed mach error %d errno %d\n", (uintmax_t)ssiz, stack_prot, error, vm_mmap_to_errno(error)); return (vm_mmap_to_errno(error)); } /* * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they * are still used to enforce the stack rlimit on the process stack. */ vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; vmspace->vm_maxsaddr = (char *)stack_addr; return (0); } /* * Copy out argument and environment strings from the old process address * space into the temporary string buffer. */ int exec_copyin_args(struct image_args *args, const char *fname, enum uio_seg segflg, char **argv, char **envv) { u_long arg, env; int error; bzero(args, sizeof(*args)); if (argv == NULL) return (EFAULT); /* * Allocate demand-paged memory for the file name, argument, and * environment strings. */ error = exec_alloc_args(args); if (error != 0) return (error); /* * Copy the file name. */ error = exec_args_add_fname(args, fname, segflg); if (error != 0) goto err_exit; /* * extract arguments first */ for (;;) { error = fueword(argv++, &arg); if (error == -1) { error = EFAULT; goto err_exit; } if (arg == 0) break; error = exec_args_add_arg(args, (char *)(uintptr_t)arg, UIO_USERSPACE); if (error != 0) goto err_exit; } /* * extract environment strings */ if (envv) { for (;;) { error = fueword(envv++, &env); if (error == -1) { error = EFAULT; goto err_exit; } if (env == 0) break; error = exec_args_add_env(args, (char *)(uintptr_t)env, UIO_USERSPACE); if (error != 0) goto err_exit; } } return (0); err_exit: exec_free_args(args); return (error); } int exec_copyin_data_fds(struct thread *td, struct image_args *args, const void *data, size_t datalen, const int *fds, size_t fdslen) { struct filedesc *ofdp; const char *p; int *kfds; int error; memset(args, '\0', sizeof(*args)); ofdp = td->td_proc->p_fd; if (datalen >= ARG_MAX || fdslen >= ofdp->fd_nfiles) return (E2BIG); error = exec_alloc_args(args); if (error != 0) return (error); args->begin_argv = args->buf; args->stringspace = ARG_MAX; if (datalen > 0) { /* * Argument buffer has been provided. Copy it into the * kernel as a single string and add a terminating null * byte. */ error = copyin(data, args->begin_argv, datalen); if (error != 0) goto err_exit; args->begin_argv[datalen] = '\0'; args->endp = args->begin_argv + datalen + 1; args->stringspace -= datalen + 1; /* * Traditional argument counting. Count the number of * null bytes. */ for (p = args->begin_argv; p < args->endp; ++p) if (*p == '\0') ++args->argc; } else { /* No argument buffer provided. */ args->endp = args->begin_argv; } /* Create new file descriptor table. */ kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK); error = copyin(fds, kfds, fdslen * sizeof(int)); if (error != 0) { free(kfds, M_TEMP); goto err_exit; } error = fdcopy_remapped(ofdp, kfds, fdslen, &args->fdp); free(kfds, M_TEMP); if (error != 0) goto err_exit; return (0); err_exit: exec_free_args(args); return (error); } struct exec_args_kva { vm_offset_t addr; u_int gen; SLIST_ENTRY(exec_args_kva) next; }; DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; static struct mtx exec_args_kva_mtx; static u_int exec_args_gen; static void exec_prealloc_args_kva(void *arg __unused) { struct exec_args_kva *argkva; u_int i; SLIST_INIT(&exec_args_kva_freelist); mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); for (i = 0; i < exec_map_entries; i++) { argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); argkva->gen = exec_args_gen; SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); } } SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); static vm_offset_t exec_alloc_args_kva(void **cookie) { struct exec_args_kva *argkva; argkva = (void *)atomic_readandclear_ptr( (uintptr_t *)DPCPU_PTR(exec_args_kva)); if (argkva == NULL) { mtx_lock(&exec_args_kva_mtx); while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) (void)mtx_sleep(&exec_args_kva_freelist, &exec_args_kva_mtx, 0, "execkva", 0); SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); mtx_unlock(&exec_args_kva_mtx); } *(struct exec_args_kva **)cookie = argkva; return (argkva->addr); } static void exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) { vm_offset_t base; base = argkva->addr; if (argkva->gen != gen) { (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, MADV_FREE); argkva->gen = gen; } if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), (uintptr_t)NULL, (uintptr_t)argkva)) { mtx_lock(&exec_args_kva_mtx); SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); wakeup_one(&exec_args_kva_freelist); mtx_unlock(&exec_args_kva_mtx); } } static void exec_free_args_kva(void *cookie) { exec_release_args_kva(cookie, exec_args_gen); } static void exec_args_kva_lowmem(void *arg __unused) { SLIST_HEAD(, exec_args_kva) head; struct exec_args_kva *argkva; u_int gen; int i; gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; /* * Force an madvise of each KVA range. Any currently allocated ranges * will have MADV_FREE applied once they are freed. */ SLIST_INIT(&head); mtx_lock(&exec_args_kva_mtx); SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); mtx_unlock(&exec_args_kva_mtx); while ((argkva = SLIST_FIRST(&head)) != NULL) { SLIST_REMOVE_HEAD(&head, next); exec_release_args_kva(argkva, gen); } CPU_FOREACH(i) { argkva = (void *)atomic_readandclear_ptr( (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); if (argkva != NULL) exec_release_args_kva(argkva, gen); } } EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, EVENTHANDLER_PRI_ANY); /* * Allocate temporary demand-paged, zero-filled memory for the file name, * argument, and environment strings. */ int exec_alloc_args(struct image_args *args) { args->buf = (char *)exec_alloc_args_kva(&args->bufkva); return (0); } void exec_free_args(struct image_args *args) { if (args->buf != NULL) { exec_free_args_kva(args->bufkva); args->buf = NULL; } if (args->fname_buf != NULL) { free(args->fname_buf, M_TEMP); args->fname_buf = NULL; } if (args->fdp != NULL) fdescfree_remapped(args->fdp); } /* * A set to functions to fill struct image args. * * NOTE: exec_args_add_fname() must be called (possibly with a NULL * fname) before the other functions. All exec_args_add_arg() calls must * be made before any exec_args_add_env() calls. exec_args_adjust_args() * may be called any time after exec_args_add_fname(). * * exec_args_add_fname() - install path to be executed * exec_args_add_arg() - append an argument string * exec_args_add_env() - append an env string * exec_args_adjust_args() - adjust location of the argument list to * allow new arguments to be prepended */ int exec_args_add_fname(struct image_args *args, const char *fname, enum uio_seg segflg) { int error; size_t length; KASSERT(args->fname == NULL, ("fname already appended")); KASSERT(args->endp == NULL, ("already appending to args")); if (fname != NULL) { args->fname = args->buf; error = segflg == UIO_SYSSPACE ? copystr(fname, args->fname, PATH_MAX, &length) : copyinstr(fname, args->fname, PATH_MAX, &length); if (error != 0) return (error == ENAMETOOLONG ? E2BIG : error); } else length = 0; /* Set up for _arg_*()/_env_*() */ args->endp = args->buf + length; /* begin_argv must be set and kept updated */ args->begin_argv = args->endp; KASSERT(exec_map_entry_size - length >= ARG_MAX, ("too little space remaining for arguments %zu < %zu", exec_map_entry_size - length, (size_t)ARG_MAX)); args->stringspace = ARG_MAX; return (0); } static int exec_args_add_str(struct image_args *args, const char *str, enum uio_seg segflg, int *countp) { int error; size_t length; KASSERT(args->endp != NULL, ("endp not initialized")); KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); error = (segflg == UIO_SYSSPACE) ? copystr(str, args->endp, args->stringspace, &length) : copyinstr(str, args->endp, args->stringspace, &length); if (error != 0) return (error == ENAMETOOLONG ? E2BIG : error); args->stringspace -= length; args->endp += length; (*countp)++; return (0); } int exec_args_add_arg(struct image_args *args, const char *argp, enum uio_seg segflg) { KASSERT(args->envc == 0, ("appending args after env")); return (exec_args_add_str(args, argp, segflg, &args->argc)); } int exec_args_add_env(struct image_args *args, const char *envp, enum uio_seg segflg) { if (args->envc == 0) args->begin_envv = args->endp; return (exec_args_add_str(args, envp, segflg, &args->envc)); } int exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) { ssize_t offset; KASSERT(args->endp != NULL, ("endp not initialized")); KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); offset = extend - consume; if (args->stringspace < offset) return (E2BIG); memmove(args->begin_argv + extend, args->begin_argv + consume, args->endp - args->begin_argv + consume); if (args->envc > 0) args->begin_envv += offset; args->endp += offset; args->stringspace -= offset; return (0); } char * exec_args_get_begin_envv(struct image_args *args) { KASSERT(args->endp != NULL, ("endp not initialized")); if (args->envc > 0) return (args->begin_envv); return (args->endp); } void exec_stackgap(struct image_params *imgp, uintptr_t *dp) { if (imgp->sysent->sv_stackgap == NULL || (imgp->proc->p_fctl0 & (NT_FREEBSD_FCTL_ASLR_DISABLE | NT_FREEBSD_FCTL_ASG_DISABLE)) != 0 || (imgp->map_flags & MAP_ASLR) == 0) return; imgp->sysent->sv_stackgap(imgp, dp); } /* * Copy strings out to the new process address space, constructing new arg * and env vector tables. Return a pointer to the base so that it can be used * as the initial stack pointer. */ int exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) { int argc, envc; char **vectp; char *stringp; uintptr_t destp, ustringp; struct ps_strings *arginfo; struct proc *p; size_t execpath_len; int error, szsigcode, szps; char canary[sizeof(long) * 8]; szps = sizeof(pagesizes[0]) * MAXPAGESIZES; /* * Calculate string base and vector table pointers. * Also deal with signal trampoline code for this exec type. */ if (imgp->execpath != NULL && imgp->auxargs != NULL) execpath_len = strlen(imgp->execpath) + 1; else execpath_len = 0; p = imgp->proc; szsigcode = 0; arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; imgp->ps_strings = arginfo; if (p->p_sysent->sv_sigcode_base == 0) { if (p->p_sysent->sv_szsigcode != NULL) szsigcode = *(p->p_sysent->sv_szsigcode); } destp = (uintptr_t)arginfo; /* * install sigcode */ if (szsigcode != 0) { destp -= szsigcode; destp = rounddown2(destp, sizeof(void *)); error = copyout(p->p_sysent->sv_sigcode, (void *)destp, szsigcode); if (error != 0) return (error); } /* * Copy the image path for the rtld. */ if (execpath_len != 0) { destp -= execpath_len; destp = rounddown2(destp, sizeof(void *)); imgp->execpathp = (void *)destp; error = copyout(imgp->execpath, imgp->execpathp, execpath_len); if (error != 0) return (error); } /* * Prepare the canary for SSP. */ arc4rand(canary, sizeof(canary), 0); destp -= sizeof(canary); imgp->canary = (void *)destp; error = copyout(canary, imgp->canary, sizeof(canary)); if (error != 0) return (error); imgp->canarylen = sizeof(canary); /* * Prepare the pagesizes array. */ destp -= szps; destp = rounddown2(destp, sizeof(void *)); imgp->pagesizes = (void *)destp; error = copyout(pagesizes, imgp->pagesizes, szps); if (error != 0) return (error); imgp->pagesizeslen = szps; /* * Allocate room for the argument and environment strings. */ destp -= ARG_MAX - imgp->args->stringspace; destp = rounddown2(destp, sizeof(void *)); ustringp = destp; exec_stackgap(imgp, &destp); if (imgp->auxargs) { /* * Allocate room on the stack for the ELF auxargs * array. It has up to AT_COUNT entries. */ destp -= AT_COUNT * sizeof(Elf_Auxinfo); destp = rounddown2(destp, sizeof(void *)); } vectp = (char **)destp; /* * Allocate room for the argv[] and env vectors including the * terminating NULL pointers. */ vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; /* * vectp also becomes our initial stack base */ *stack_base = (uintptr_t)vectp; stringp = imgp->args->begin_argv; argc = imgp->args->argc; envc = imgp->args->envc; /* * Copy out strings - arguments and environment. */ error = copyout(stringp, (void *)ustringp, ARG_MAX - imgp->args->stringspace); if (error != 0) return (error); /* * Fill in "ps_strings" struct for ps, w, etc. */ imgp->argv = vectp; if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || suword32(&arginfo->ps_nargvstr, argc) != 0) return (EFAULT); /* * Fill in argument portion of vector table. */ for (; argc > 0; --argc) { if (suword(vectp++, ustringp) != 0) return (EFAULT); while (*stringp++ != 0) ustringp++; ustringp++; } /* a null vector table pointer separates the argp's from the envp's */ if (suword(vectp++, 0) != 0) return (EFAULT); imgp->envv = vectp; if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || suword32(&arginfo->ps_nenvstr, envc) != 0) return (EFAULT); /* * Fill in environment portion of vector table. */ for (; envc > 0; --envc) { if (suword(vectp++, ustringp) != 0) return (EFAULT); while (*stringp++ != 0) ustringp++; ustringp++; } /* end of vector table is a null pointer */ if (suword(vectp, 0) != 0) return (EFAULT); if (imgp->auxargs) { vectp++; error = imgp->sysent->sv_copyout_auxargs(imgp, (uintptr_t)vectp); if (error != 0) return (error); } return (0); } /* * Check permissions of file to execute. * Called with imgp->vp locked. * Return 0 for success or error code on failure. */ int exec_check_permissions(struct image_params *imgp) { struct vnode *vp = imgp->vp; struct vattr *attr = imgp->attr; struct thread *td; int error; td = curthread; /* Get file attributes */ error = VOP_GETATTR(vp, attr, td->td_ucred); if (error) return (error); #ifdef MAC error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); if (error) return (error); #endif /* * 1) Check if file execution is disabled for the filesystem that * this file resides on. * 2) Ensure that at least one execute bit is on. Otherwise, a * privileged user will always succeed, and we don't want this * to happen unless the file really is executable. * 3) Ensure that the file is a regular file. */ if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || (attr->va_type != VREG)) return (EACCES); /* * Zero length files can't be exec'd */ if (attr->va_size == 0) return (ENOEXEC); /* * Check for execute permission to file based on current credentials. */ error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); if (error) return (error); /* * Check number of open-for-writes on the file and deny execution * if there are any. * * Add a text reference now so no one can write to the * executable while we're activating it. * * Remember if this was set before and unset it in case this is not * actually an executable image. */ error = VOP_SET_TEXT(vp); if (error != 0) return (error); imgp->textset = true; /* * Call filesystem specific open routine (which does nothing in the * general case). */ error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); if (error == 0) imgp->opened = 1; return (error); } /* * Exec handler registration */ int exec_register(const struct execsw *execsw_arg) { const struct execsw **es, **xs, **newexecsw; u_int count = 2; /* New slot and trailing NULL */ if (execsw) for (es = execsw; *es; es++) count++; newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); xs = newexecsw; if (execsw) for (es = execsw; *es; es++) *xs++ = *es; *xs++ = execsw_arg; *xs = NULL; if (execsw) free(execsw, M_TEMP); execsw = newexecsw; return (0); } int exec_unregister(const struct execsw *execsw_arg) { const struct execsw **es, **xs, **newexecsw; int count = 1; if (execsw == NULL) panic("unregister with no handlers left?\n"); for (es = execsw; *es; es++) { if (*es == execsw_arg) break; } if (*es == NULL) return (ENOENT); for (es = execsw; *es; es++) if (*es != execsw_arg) count++; newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); xs = newexecsw; for (es = execsw; *es; es++) if (*es != execsw_arg) *xs++ = *es; *xs = NULL; if (execsw) free(execsw, M_TEMP); execsw = newexecsw; return (0); }