From 39b3385dde64babd316ffd97dd79f9236e487ccb Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 7 Nov 2001 00:31:36 +0000 Subject: Update. 2001-11-06 Ulrich Drepper * elf/dl-load.c (decompose_rpath): Optimize error handling for size. (_dl_init_paths): Likewise. (_dl_map_object_from_fd): Likewise. --- elf/dl-load.c | 236 ++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 154 insertions(+), 82 deletions(-) (limited to 'elf/dl-load.c') diff --git a/elf/dl-load.c b/elf/dl-load.c index c397edd1e2..421a72dfc2 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -228,7 +228,7 @@ _dl_dst_substitute (struct link_map *l, const char *name, char *result, do { - if (__builtin_expect (*name, 'a') == '$') + if (__builtin_expect (*name == '$', 0)) { const char *repl = NULL; size_t len = 1; @@ -504,6 +504,8 @@ decompose_rpath (struct r_search_path_struct *sps, char *cp; struct r_search_path_elem **result; size_t nelems; + /* Initialize to please the compiler. */ + const char *errstring = NULL; /* First see whether we must forget the RUNPATH and RPATH from this object. */ @@ -521,8 +523,13 @@ decompose_rpath (struct r_search_path_struct *sps, result = (struct r_search_path_elem **) malloc (sizeof (*result)); if (result == NULL) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create cache for search path")); + { + signal_error_cache: + errstring = N_("cannot create cache for search path"); + signal_error: + _dl_signal_error (ENOMEM, NULL, NULL, errstring); + } + result[0] = NULL; sps->dirs = result; @@ -537,8 +544,10 @@ decompose_rpath (struct r_search_path_struct *sps, string tokens. */ copy = expand_dynamic_string_token (l, rpath); if (copy == NULL) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create RUNPATH/RPATH copy")); + { + errstring = N_("cannot create RUNPATH/RPATH copy"); + goto signal_error; + } /* Count the number of necessary elements in the result array. */ nelems = 0; @@ -551,8 +560,7 @@ decompose_rpath (struct r_search_path_struct *sps, result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1) * sizeof (*result)); if (result == NULL) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create cache for search path")); + goto signal_error_cache; fillin_rpath (copy, result, ":", 0, what, where); @@ -577,6 +585,8 @@ _dl_init_paths (const char *llp) #ifdef SHARED struct link_map *l; #endif + /* Initialize to please the compiler. */ + const char *errstring = NULL; /* Fill in the information about the application's RPATH and the directories addressed by the LD_LIBRARY_PATH environment variable. */ @@ -589,8 +599,11 @@ _dl_init_paths (const char *llp) aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **) malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *)); if (rtld_search_dirs.dirs == NULL) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create search path array")); + { + errstring = N_("cannot create search path array"); + signal_error: + _dl_signal_error (ENOMEM, NULL, NULL, errstring); + } round_size = ((2 * sizeof (struct r_search_path_elem) - 1 + ncapstr * sizeof (enum r_dir_status)) @@ -600,8 +613,10 @@ _dl_init_paths (const char *llp) malloc ((sizeof (system_dirs) / sizeof (system_dirs[0])) * round_size * sizeof (struct r_search_path_elem)); if (rtld_search_dirs.dirs[0] == NULL) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create cache for search path")); + { + errstring = N_("cannot create cache for search path"); + goto signal_error; + } rtld_search_dirs.malloced = 0; pelem = _dl_all_dirs = rtld_search_dirs.dirs[0]; @@ -693,8 +708,10 @@ _dl_init_paths (const char *llp) env_path_list.dirs = (struct r_search_path_elem **) malloc ((nllp + 1) * sizeof (struct r_search_path_elem *)); if (env_path_list.dirs == NULL) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create cache for search path")); + { + errstring = N_("cannot create cache for search path"); + goto signal_error; + } (void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;", __libc_enable_secure, "LD_LIBRARY_PATH", NULL); @@ -721,7 +738,6 @@ _dl_init_paths (const char *llp) performance does not count. The function used to be "inlinable" and the compiled did so all the time. This increased the code size for absolutely no good reason. */ -#define LOSE(code, s) lose (code, fd, name, realname, l, s) static void __attribute__ ((noreturn)) lose (int code, int fd, const char *name, char *realname, struct link_map *l, @@ -761,31 +777,25 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, int mode) { struct link_map *l = NULL; - - auto inline caddr_t map_segment (ElfW(Addr) mapstart, size_t len, - int prot, int fixed, off_t offset); - - inline caddr_t map_segment (ElfW(Addr) mapstart, size_t len, - int prot, int fixed, off_t offset) - { - caddr_t mapat = __mmap ((caddr_t) mapstart, len, prot, - fixed|MAP_COPY|MAP_FILE, - fd, offset); - if (mapat == MAP_FAILED) - LOSE (errno, N_("failed to map segment from shared object")); - return mapat; - } - const ElfW(Ehdr) *header; const ElfW(Phdr) *phdr; const ElfW(Phdr) *ph; size_t maplength; int type; struct stat64 st; + /* Initialize to keep the compiler happy. */ + const char *errstring = NULL; + int errval = 0; /* Get file information. */ - if (__fxstat64 (_STAT_VER, fd, &st) < 0) - LOSE (errno, N_("cannot stat shared object")); + if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st) < 0, 0)) + { + errstring = N_("cannot stat shared object"); + call_lose_errno: + errval = errno; + call_lose: + lose (errval, fd, name, realname, l, errstring); + } /* Look again to see if the real name matched another already loaded. */ for (l = _dl_loaded; l; l = l->l_next) @@ -832,7 +842,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, /* Enter the new object in the list of loaded objects. */ l = _dl_new_object (realname, name, l_type, loader); if (__builtin_expect (! l, 0)) - LOSE (ENOMEM, N_("cannot create shared object descriptor")); + { + errstring = N_("cannot create shared object descriptor"); + goto call_lose_errno; + } /* Extract the remaining details we need from the ELF header and then read in the program header table. */ @@ -848,7 +861,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, phdr = alloca (maplength); __lseek (fd, SEEK_SET, header->e_phoff); if (__libc_read (fd, (void *) phdr, maplength) != maplength) - LOSE (errno, N_("cannot read file data")); + { + errstring = N_("cannot read file data"); + goto call_lose_errno; + } } { @@ -875,6 +891,7 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, l->l_ld = (void *) ph->p_vaddr; l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn)); break; + case PT_PHDR: l->l_phdr = (void *) ph->p_vaddr; break; @@ -882,11 +899,18 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, case PT_LOAD: /* A load command tells us to map in part of the file. We record the load commands and process them all later. */ - if (ph->p_align % _dl_pagesize != 0) - LOSE (0, N_("ELF load command alignment not page-aligned")); - if ((ph->p_vaddr - ph->p_offset) % ph->p_align) - LOSE (0, - N_("ELF load command address/offset not properly aligned")); + if ((ph->p_align & (_dl_pagesize - 1)) != 0) + { + errstring = N_("ELF load command alignment not page-aligned"); + goto call_lose; + } + if (((ph->p_vaddr - ph->p_offset) & (ph->p_align - 1)) != 0) + { + errstring + = N_("ELF load command address/offset not properly aligned"); + goto call_lose; + } + { struct loadcmd *c = &loadcmds[nloadcmds++]; c->mapstart = ph->p_vaddr & ~(ph->p_align - 1); @@ -938,8 +962,16 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, - MAP_BASE_ADDR (l)); /* Remember which part of the address space this object uses. */ - l->l_map_start = (ElfW(Addr)) map_segment (mappref, maplength, c->prot, - 0, c->mapoff); + l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength, + c->prot, MAP_COPY | MAP_FILE, + fd, c->mapoff); + if ((void *) l->l_map_start == MAP_FAILED) + { + map_error: + errstring = N_("failed to map segment from shared object"); + goto call_lose_errno; + } + l->l_map_end = l->l_map_start + maplength; l->l_addr = l->l_map_start - c->mapstart; @@ -960,7 +992,8 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, happen for objects loaded with dlopen(). */ if (__builtin_expect (mode & __RTLD_DLOPEN, 0)) { - LOSE (0, N_("cannot dynamically load executable")); + errstring = N_("cannot dynamically load executable"); + goto call_lose; } /* Notify ELF_PREFERRED_ADDRESS that we have to load this one @@ -974,10 +1007,13 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, while (c < &loadcmds[nloadcmds]) { - if (c->mapend > c->mapstart) - /* Map the segment contents from the file. */ - map_segment (l->l_addr + c->mapstart, c->mapend - c->mapstart, - c->prot, MAP_FIXED, c->mapoff); + if (c->mapend > c->mapstart + /* Map the segment contents from the file. */ + && (__mmap ((void *) (l->l_addr + c->mapstart), + c->mapend - c->mapstart, c->prot, + MAP_FIXED | MAP_COPY | MAP_FILE, fd, c->mapoff) + == MAP_FAILED)) + goto map_error; postmap: if (l->l_phdr == 0 @@ -1010,7 +1046,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, /* Dag nab it. */ if (__mprotect ((caddr_t) (zero & ~(_dl_pagesize - 1)), _dl_pagesize, c->prot|PROT_WRITE) < 0) - LOSE (errno, N_("cannot change memory protections")); + { + errstring = N_("cannot change memory protections"); + goto call_lose_errno; + } } memset ((void *) zero, '\0', zeropage - zero); if ((c->prot & PROT_WRITE) == 0) @@ -1026,7 +1065,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED, ANONFD, 0); if (mapat == MAP_FAILED) - LOSE (errno, N_("cannot map zero-fill pages")); + { + errstring = N_("cannot map zero-fill pages"); + goto call_lose_errno; + } } } @@ -1041,7 +1083,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum * sizeof (ElfW(Phdr))); if (newp == NULL) - LOSE (ENOMEM, N_("cannot allocate memory for program header")); + { + errstring = N_("cannot allocate memory for program header"); + goto call_lose_errno; + } l->l_phdr = memcpy (newp, phdr, (header->e_phnum * sizeof (ElfW(Phdr)))); @@ -1061,7 +1106,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, if (l->l_ld == 0) { if (type == ET_DYN) - LOSE (0, N_("object file has no dynamic section")); + { + errstring = N_("object file has no dynamic section"); + goto call_lose; + } } else (ElfW(Addr)) l->l_ld += l->l_addr; @@ -1129,7 +1177,10 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, (struct link_map **) malloc (sizeof (struct link_map *)); if (l->l_symbolic_searchlist.r_list == NULL) - LOSE (ENOMEM, N_("cannot create searchlist")); + { + errstring = N_("cannot create searchlist"); + goto call_lose_errno; + } l->l_symbolic_searchlist.r_list[0] = l; l->l_symbolic_searchlist.r_nlist = 1; @@ -1143,7 +1194,7 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp, } /* Remember whether this object must be initialized first. */ - if (__builtin_expect (l->l_flags_1 & DF_1_INITFIRST, 0)) + if (l->l_flags_1 & DF_1_INITFIRST) _dl_initfirst = l; /* Finally the file information. */ @@ -1223,11 +1274,17 @@ open_verify (const char *name, struct filebuf *fbp) [EI_OSABI] = ELFOSABI_SYSV, [EI_ABIVERSION] = 0 }; - static const struct { - ElfW(Word) vendorlen, datalen, type; + static const struct + { + ElfW(Word) vendorlen; + ElfW(Word) datalen; + ElfW(Word) type; char vendor[4]; } expected_note = { 4, 16, 1, "GNU" }; int fd; + /* Initialize it to make the compiler happy. */ + const char *errstring = NULL; + int errval = 0; /* Open the file. We always open files read-only. */ fd = __open (name, O_RDONLY); @@ -1250,8 +1307,13 @@ open_verify (const char *name, struct filebuf *fbp) /* Now run the tests. */ if (__builtin_expect (fbp->len < (ssize_t) sizeof (ElfW(Ehdr)), 0)) - lose (errno, fd, name, NULL, NULL, - errno == 0 ? N_("file too short") : N_("cannot read file data")); + { + errval = errno; + errstring = (errval == 0 + ? N_("file too short") : N_("cannot read file data")); + call_lose: + lose (errval, fd, name, NULL, NULL, errstring); + } /* See whether the ELF header is what we expect. */ if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected, @@ -1271,49 +1333,54 @@ open_verify (const char *name, struct filebuf *fbp) (ELFMAG3 << (EI_MAG0 * 8))) #endif ) - lose (0, fd, name, NULL, NULL, N_("invalid ELF header")); - - if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS)) + errstring = N_("invalid ELF header"); + else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS)) /* This is not a fatal error. On architectures where 32-bit and 64-bit binaries can be run this might happen. */ goto close_and_out; - - if (ehdr->e_ident[EI_DATA] != byteorder) + else if (ehdr->e_ident[EI_DATA] != byteorder) { if (BYTE_ORDER == BIG_ENDIAN) - lose (0, fd, name, NULL, NULL, - "ELF file data encoding not big-endian"); + errstring = N_("ELF file data encoding not big-endian"); else - lose (0, fd, name, NULL, NULL, - "ELF file data encoding not little-endian"); + errstring = N_("ELF file data encoding not little-endian"); } - if (ehdr->e_ident[EI_VERSION] != EV_CURRENT) - lose (0, fd, name, NULL, NULL, - N_("ELF file version ident does not match current one")); + else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT) + errstring + = N_("ELF file version ident does not match current one"); /* XXX We should be able so set system specific versions which are allowed here. */ - if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI])) - lose (0, fd, name, NULL, NULL, N_("ELF file OS ABI invalid")); - if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_ABIVERSION])) - lose (0, fd, name, NULL, NULL, - N_("ELF file ABI version invalid")); - lose (0, fd, name, NULL, NULL, N_("internal error")); + else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI])) + errstring = N_("ELF file OS ABI invalid"); + else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_ABIVERSION])) + errstring = N_("ELF file ABI version invalid"); + else + /* Otherwise we don't know what went wrong. */ + errstring = N_("internal error"); + + goto call_lose; } if (__builtin_expect (ehdr->e_version, EV_CURRENT) != EV_CURRENT) - lose (0, fd, name, NULL, NULL, - N_("ELF file version does not match current one")); + { + errstring = N_("ELF file version does not match current one"); + goto call_lose; + } if (! __builtin_expect (elf_machine_matches_host (ehdr), 1)) goto close_and_out; else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr))) != sizeof (ElfW(Phdr))) - lose (0, fd, name, NULL, NULL, - N_("ELF file's phentsize not the expected size")); + { + errstring = N_("ELF file's phentsize not the expected size"); + goto call_lose; + } else if (__builtin_expect (ehdr->e_type, ET_DYN) != ET_DYN && __builtin_expect (ehdr->e_type, ET_EXEC) != ET_EXEC) - lose (0, fd, name, NULL, NULL, - N_("only ET_DYN and ET_EXEC can be loaded")); + { + errstring = N_("only ET_DYN and ET_EXEC can be loaded"); + goto call_lose; + } maplength = ehdr->e_phnum * sizeof (ElfW(Phdr)); if (ehdr->e_phoff + maplength <= fbp->len) @@ -1323,7 +1390,12 @@ open_verify (const char *name, struct filebuf *fbp) phdr = alloca (maplength); __lseek (fd, SEEK_SET, ehdr->e_phoff); if (__libc_read (fd, (void *) phdr, maplength) != maplength) - lose (errno, fd, name, NULL, NULL, N_("cannot read file data")); + { + read_error: + errval = errno; + errstring = N_("cannot read file data"); + goto call_lose; + } } /* Check .note.ABI-tag if present. */ @@ -1336,8 +1408,8 @@ open_verify (const char *name, struct filebuf *fbp) { __lseek (fd, SEEK_SET, ph->p_offset); if (__libc_read (fd, (void *) abi_note_buf, 32) != 32) - lose (errno, fd, name, NULL, NULL, - N_("cannot read file data")); + goto read_error; + abi_note = abi_note_buf; } -- cgit v1.2.3