diff options
Diffstat (limited to 'linker/linker.c')
| -rw-r--r-- | linker/linker.c | 409 |
1 files changed, 320 insertions, 89 deletions
diff --git a/linker/linker.c b/linker/linker.c index 300a95c..50eb415 100644 --- a/linker/linker.c +++ b/linker/linker.c @@ -51,7 +51,11 @@ #include "ba.h" -#define SO_MAX 64 +#define SO_MAX 96 + +/* Assume average path length of 64 and max 8 paths */ +#define LDPATH_BUFSIZE 512 +#define LDPATH_MAX 8 /* >>> IMPORTANT NOTE - READ ME BEFORE MODIFYING <<< * @@ -66,18 +70,12 @@ * - should we do anything special for STB_WEAK symbols? * - are we doing everything we should for ARM_COPY relocations? * - cleaner error reporting - * - configuration for paths (LD_LIBRARY_PATH?) * - after linking, set as much stuff as possible to READONLY * and NOEXEC * - linker hardcodes PAGE_SIZE and PAGE_MASK because the kernel * headers provide versions that are negative... * - allocate space for soinfo structs dynamically instead of * having a hard limit (64) - * - * features to add someday: - * - * - dlopen() and friends - * */ @@ -89,6 +87,9 @@ static soinfo *freelist = NULL; static soinfo *solist = &libdl_info; static soinfo *sonext = &libdl_info; +static char ldpaths_buf[LDPATH_BUFSIZE]; +static const char *ldpaths[LDPATH_MAX + 1]; + int debug_verbosity; static int pid; @@ -104,6 +105,32 @@ unsigned bitmask[4096]; #define PT_ARM_EXIDX 0x70000001 /* .ARM.exidx segment */ #endif +#define HOODLUM(name, ret, ...) \ + ret name __VA_ARGS__ \ + { \ + char errstr[] = "ERROR: " #name " called from the dynamic linker!\n"; \ + write(2, errstr, sizeof(errstr)); \ + abort(); \ + } +HOODLUM(malloc, void *, (size_t size)); +HOODLUM(free, void, (void *ptr)); +HOODLUM(realloc, void *, (void *ptr, size_t size)); +HOODLUM(calloc, void *, (size_t cnt, size_t size)); + +static char tmp_err_buf[768]; +static char __linker_dl_err_buf[768]; +#define DL_ERR(fmt, x...) \ + do { \ + snprintf(__linker_dl_err_buf, sizeof(__linker_dl_err_buf), \ + "%s[%d]: " fmt, __func__, __LINE__, ##x); \ + ERROR(fmt "\n", ##x); \ + } while(0) + +const char *linker_get_error(void) +{ + return (const char *)&__linker_dl_err_buf[0]; +} + /* * This function is an empty stub where GDB locates a breakpoint to get notified * about linker activity. @@ -125,6 +152,7 @@ static void insert_soinfo_into_debug_map(soinfo * info) map = &(info->linkmap); map->l_addr = info->base; map->l_name = (char*) info->name; + map->l_ld = (uintptr_t)info->dynamic; /* Stick the new library at the end of the list. * gdb tends to care more about libc than it does @@ -207,7 +235,7 @@ static soinfo *alloc_info(const char *name) soinfo *si; if(strlen(name) >= SOINFO_NAME_LEN) { - ERROR("%5d library name %s too long\n", pid, name); + DL_ERR("%5d library name %s too long", pid, name); return 0; } @@ -216,7 +244,7 @@ static soinfo *alloc_info(const char *name) */ if (!freelist) { if(socount == SO_MAX) { - ERROR("%5d too many libraries when loading %s\n", pid, name); + DL_ERR("%5d too many libraries when loading %s", pid, name); return NULL; } freelist = sopool + socount++; @@ -252,7 +280,7 @@ static void free_info(soinfo *si) } if (trav == NULL) { /* si was not ni solist */ - ERROR("%5d name %s is not in solist!\n", pid, si->name); + DL_ERR("%5d name %s is not in solist!", pid, si->name); return; } @@ -317,7 +345,7 @@ _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount) *pcount = 0; return NULL; } -#elif defined(ANDROID_X86_LINKER) +#elif defined(ANDROID_X86_LINKER) || defined(ANDROID_SH_LINKER) /* Here, we only have to provide a callback to iterate across all the * loaded libraries. gcc_eh does the rest. */ int @@ -477,13 +505,12 @@ static int _open_lib(const char *name) return -1; } -/* TODO: Need to add support for initializing the so search path with - * LD_LIBRARY_PATH env variable for non-setuid programs. */ static int open_library(const char *name) { int fd; char buf[512]; const char **path; + int n; TRACE("[ %5d opening %s ]\n", pid, name); @@ -493,8 +520,21 @@ static int open_library(const char *name) if ((name[0] == '/') && ((fd = _open_lib(name)) >= 0)) return fd; + for (path = ldpaths; *path; path++) { + n = snprintf(buf, sizeof(buf), "%s/%s", *path, name); + if (n < 0 || n >= (int)sizeof(buf)) { + WARN("Ignoring very long library path: %s/%s\n", *path, name); + continue; + } + if ((fd = _open_lib(buf)) >= 0) + return fd; + } for (path = sopaths; *path; path++) { - snprintf(buf, sizeof(buf), "%s/%s", *path, name); + n = snprintf(buf, sizeof(buf), "%s/%s", *path, name); + if (n < 0 || n >= (int)sizeof(buf)) { + WARN("Ignoring very long library path: %s/%s\n", *path, name); + continue; + } if ((fd = _open_lib(buf)) >= 0) return fd; } @@ -521,7 +561,7 @@ is_prelinked(int fd, const char *name) sz = lseek(fd, -sizeof(prelink_info_t), SEEK_END); if (sz < 0) { - ERROR("lseek() failed!\n"); + DL_ERR("lseek() failed!"); return 0; } @@ -597,7 +637,7 @@ get_lib_extents(int fd, const char *name, void *__hdr, unsigned *total_sz) TRACE("[ %5d Computing extents for '%s'. ]\n", pid, name); if (verify_elf_object(_hdr, name) < 0) { - ERROR("%5d - %s is not a valid ELF object\n", pid, name); + DL_ERR("%5d - %s is not a valid ELF object", pid, name); return (unsigned)-1; } @@ -625,7 +665,7 @@ get_lib_extents(int fd, const char *name, void *__hdr, unsigned *total_sz) } if ((min_vaddr == 0xffffffff) && (max_vaddr == 0)) { - ERROR("%5d - No loadable segments found in %s.\n", pid, name); + DL_ERR("%5d - No loadable segments found in %s.", pid, name); return (unsigned)-1; } @@ -661,14 +701,14 @@ static int reserve_mem_region(soinfo *si) void *base = mmap((void *)si->base, si->size, PROT_READ | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (base == MAP_FAILED) { - ERROR("%5d can NOT map (%sprelinked) library '%s' at 0x%08x " - "as requested, will try general pool: %d (%s)\n", + DL_ERR("%5d can NOT map (%sprelinked) library '%s' at 0x%08x " + "as requested, will try general pool: %d (%s)", pid, (si->base ? "" : "non-"), si->name, si->base, errno, strerror(errno)); return -1; } else if (base != (void *)si->base) { - ERROR("OOPS: %5d %sprelinked library '%s' mapped at 0x%08x, " - "not at 0x%08x\n", pid, (si->base ? "" : "non-"), + DL_ERR("OOPS: %5d %sprelinked library '%s' mapped at 0x%08x, " + "not at 0x%08x", pid, (si->base ? "" : "non-"), si->name, (unsigned)base, si->base); munmap(base, si->size); return -1; @@ -705,7 +745,7 @@ alloc_mem_region(soinfo *si) } err: - ERROR("OOPS: %5d cannot map library '%s'. no vspace available.\n", + DL_ERR("OOPS: %5d cannot map library '%s'. no vspace available.", pid, si->name); return -1; } @@ -764,8 +804,8 @@ load_segments(int fd, void *header, soinfo *si) MAP_PRIVATE | MAP_FIXED, fd, phdr->p_offset & (~PAGE_MASK)); if (pbase == MAP_FAILED) { - ERROR("%d failed to map segment from '%s' @ 0x%08x (0x%08x). " - "p_vaddr=0x%08x p_offset=0x%08x\n", pid, si->name, + DL_ERR("%d failed to map segment from '%s' @ 0x%08x (0x%08x). " + "p_vaddr=0x%08x p_offset=0x%08x", pid, si->name, (unsigned)tmp, len, phdr->p_vaddr, phdr->p_offset); goto fail; } @@ -820,8 +860,8 @@ load_segments(int fd, void *header, soinfo *si) MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0); if (extra_base == MAP_FAILED) { - ERROR("[ %5d - failed to extend segment from '%s' @ 0x%08x " - "(0x%08x) ]\n", pid, si->name, (unsigned)tmp, + DL_ERR("[ %5d - failed to extend segment from '%s' @ 0x%08x" + " (0x%08x) ]", pid, si->name, (unsigned)tmp, extra_len); goto fail; } @@ -873,8 +913,8 @@ load_segments(int fd, void *header, soinfo *si) /* Sanity check */ if (total_sz > si->size) { - ERROR("%5d - Total length (0x%08x) of mapped segments from '%s' is " - "greater than what was allocated (0x%08x). THIS IS BAD!\n", + DL_ERR("%5d - Total length (0x%08x) of mapped segments from '%s' is " + "greater than what was allocated (0x%08x). THIS IS BAD!", pid, total_sz, si->name, si->size); goto fail; } @@ -937,21 +977,24 @@ load_library(const char *name) int cnt; unsigned ext_sz; unsigned req_base; + const char *bname; soinfo *si = NULL; Elf32_Ehdr *hdr; - if(fd == -1) + if(fd == -1) { + DL_ERR("Library '%s' not found", name); return NULL; + } /* We have to read the ELF header to figure out what to do with this image */ if (lseek(fd, 0, SEEK_SET) < 0) { - ERROR("lseek() failed!\n"); + DL_ERR("lseek() failed!"); goto fail; } if ((cnt = read(fd, &__header[0], PAGE_SIZE)) < 0) { - ERROR("read() failed!\n"); + DL_ERR("read() failed!"); goto fail; } @@ -968,7 +1011,8 @@ load_library(const char *name) * same thing would happen if we failed during linking. Configuring the * soinfo struct here is a lot more convenient. */ - si = alloc_info(name); + bname = strrchr(name, '/'); + si = alloc_info(bname ? bname + 1 : name); if (si == NULL) goto fail; @@ -1037,13 +1081,15 @@ init_library(soinfo *si) soinfo *find_library(const char *name) { soinfo *si; + const char *bname = strrchr(name, '/'); + bname = bname ? bname + 1 : name; for(si = solist; si != 0; si = si->next){ - if(!strcmp(name, si->name)) { + if(!strcmp(bname, si->name)) { if(si->flags & FLAG_ERROR) return 0; if(si->flags & FLAG_LINKED) return si; - ERROR("OOPS: %5d recursive link to '%s'\n", pid, si->name); - return 0; + DL_ERR("OOPS: %5d recursive link to '%s'", pid, si->name); + return NULL; } } @@ -1074,7 +1120,7 @@ unsigned unload_library(soinfo *si) if(lsi) unload_library(lsi); else - ERROR("%5d could not unload '%s'\n", + DL_ERR("%5d could not unload '%s'", pid, si->strtab + d[1]); } } @@ -1121,27 +1167,27 @@ static int reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count) DEBUG("%5d Processing '%s' relocation at index %d\n", pid, si->name, idx); if(sym != 0) { - s = _do_lookup(si, strtab + symtab[sym].st_name, &base); + sym_name = (char *)(strtab + symtab[sym].st_name); + s = _do_lookup(si, sym_name, &base); if(s == 0) { - ERROR("%5d cannot locate '%s'...\n", pid, sym_name); + DL_ERR("%5d cannot locate '%s'...", pid, sym_name); return -1; } #if 0 if((base == 0) && (si->base != 0)){ /* linking from libraries to main image is bad */ - ERROR("%5d cannot locate '%s'...\n", + DL_ERR("%5d cannot locate '%s'...", pid, strtab + symtab[sym].st_name); return -1; } #endif if ((s->st_shndx == SHN_UNDEF) && (s->st_value != 0)) { - ERROR("%5d In '%s', shndx=%d && value=0x%08x. We do not " - "handle this yet\n", pid, si->name, s->st_shndx, + DL_ERR("%5d In '%s', shndx=%d && value=0x%08x. We do not " + "handle this yet", pid, si->name, s->st_shndx, s->st_value); return -1; } sym_addr = (unsigned)(s->st_value + base); - sym_name = (char *)(strtab + symtab[sym].st_name); COUNT_RELOC(RELOC_SYMBOL); } else { s = 0; @@ -1198,7 +1244,7 @@ static int reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count) COUNT_RELOC(RELOC_RELATIVE); MARK(rel->r_offset); if(sym){ - ERROR("%5d odd RELATIVE form...\n", pid); + DL_ERR("%5d odd RELATIVE form...", pid); return -1; } TRACE_TYPE(RELO, "%5d RELO RELATIVE %08x <- +%08x\n", pid, @@ -1239,7 +1285,7 @@ static int reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count) #endif /* ANDROID_ARM_LINKER */ default: - ERROR("%5d unknown reloc type %d @ %p (%d)\n", + DL_ERR("%5d unknown reloc type %d @ %p (%d)", pid, type, rel, (int) (rel - start)); return -1; } @@ -1248,13 +1294,132 @@ static int reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count) return 0; } -static void call_array(unsigned *ctor, int count) +#if defined(ANDROID_SH_LINKER) +static int reloc_library_a(soinfo *si, Elf32_Rela *rela, unsigned count) { - int n; - for(n = count; n > 0; n--){ - TRACE("[ %5d Looking at ctor *0x%08x == 0x%08x ]\n", pid, + Elf32_Sym *symtab = si->symtab; + const char *strtab = si->strtab; + Elf32_Sym *s; + unsigned base; + Elf32_Rela *start = rela; + unsigned idx; + + for (idx = 0; idx < count; ++idx) { + unsigned type = ELF32_R_TYPE(rela->r_info); + unsigned sym = ELF32_R_SYM(rela->r_info); + unsigned reloc = (unsigned)(rela->r_offset + si->base); + unsigned sym_addr = 0; + char *sym_name = NULL; + + DEBUG("%5d Processing '%s' relocation at index %d\n", pid, + si->name, idx); + if(sym != 0) { + sym_name = (char *)(strtab + symtab[sym].st_name); + s = _do_lookup(si, sym_name, &base); + if(s == 0) { + DL_ERR("%5d cannot locate '%s'...", pid, sym_name); + return -1; + } +#if 0 + if((base == 0) && (si->base != 0)){ + /* linking from libraries to main image is bad */ + DL_ERR("%5d cannot locate '%s'...", + pid, strtab + symtab[sym].st_name); + return -1; + } +#endif + if ((s->st_shndx == SHN_UNDEF) && (s->st_value != 0)) { + DL_ERR("%5d In '%s', shndx=%d && value=0x%08x. We do not " + "handle this yet", pid, si->name, s->st_shndx, + s->st_value); + return -1; + } + sym_addr = (unsigned)(s->st_value + base); + COUNT_RELOC(RELOC_SYMBOL); + } else { + s = 0; + } + +/* TODO: This is ugly. Split up the relocations by arch into + * different files. + */ + switch(type){ + case R_SH_JUMP_SLOT: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rela->r_offset); + TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) = sym_addr; + break; + case R_SH_GLOB_DAT: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rela->r_offset); + TRACE_TYPE(RELO, "%5d RELO GLOB_DAT %08x <- %08x %s\n", pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) = sym_addr; + break; + case R_SH_DIR32: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rela->r_offset); + TRACE_TYPE(RELO, "%5d RELO DIR32 %08x <- %08x %s\n", pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) += sym_addr; + break; + case R_SH_RELATIVE: + COUNT_RELOC(RELOC_RELATIVE); + MARK(rela->r_offset); + if(sym){ + DL_ERR("%5d odd RELATIVE form...", pid); + return -1; + } + TRACE_TYPE(RELO, "%5d RELO RELATIVE %08x <- +%08x\n", pid, + reloc, si->base); + *((unsigned*)reloc) += si->base; + break; + + default: + DL_ERR("%5d unknown reloc type %d @ %p (%d)", + pid, type, rela, (int) (rela - start)); + return -1; + } + rela++; + } + return 0; +} +#endif /* ANDROID_SH_LINKER */ + + +/* Please read the "Initialization and Termination functions" functions. + * of the linker design note in bionic/linker/README.TXT to understand + * what the following code is doing. + * + * The important things to remember are: + * + * DT_PREINIT_ARRAY must be called first for executables, and should + * not appear in shared libraries. + * + * DT_INIT should be called before DT_INIT_ARRAY if both are present + * + * DT_FINI should be called after DT_FINI_ARRAY if both are present + * + * DT_FINI_ARRAY must be parsed in reverse order. + */ + +static void call_array(unsigned *ctor, int count, int reverse) +{ + int n, inc = 1; + + if (reverse) { + ctor += (count-1); + inc = -1; + } + + for(n = count; n > 0; n--) { + TRACE("[ %5d Looking at %s *0x%08x == 0x%08x ]\n", pid, + reverse ? "dtor" : "ctor", (unsigned)ctor, (unsigned)*ctor); - void (*func)() = (void (*)()) *ctor++; + void (*func)() = (void (*)()) *ctor; + ctor += inc; if(((int) func == 0) || ((int) func == -1)) continue; TRACE("[ %5d Calling func @ 0x%08x ]\n", pid, (unsigned)func); func(); @@ -1263,31 +1428,20 @@ static void call_array(unsigned *ctor, int count) static void call_constructors(soinfo *si) { - /* TODO: THE ORIGINAL CODE SEEMED TO CALL THE INIT FUNCS IN THE WRONG ORDER. - * Old order: init, init_array, preinit_array.. - * Correct order: preinit_array, init, init_array. - * Verify WHY. - */ - if (si->flags & FLAG_EXE) { TRACE("[ %5d Calling preinit_array @ 0x%08x [%d] for '%s' ]\n", pid, (unsigned)si->preinit_array, si->preinit_array_count, si->name); - call_array(si->preinit_array, si->preinit_array_count); + call_array(si->preinit_array, si->preinit_array_count, 0); TRACE("[ %5d Done calling preinit_array for '%s' ]\n", pid, si->name); } else { if (si->preinit_array) { - ERROR("%5d Shared library '%s' has a preinit_array table @ 0x%08x." - " This is INVALID.\n", pid, si->name, - (unsigned)si->preinit_array); + DL_ERR("%5d Shared library '%s' has a preinit_array table @ 0x%08x." + " This is INVALID.", pid, si->name, + (unsigned)si->preinit_array); } } - // If we have an init section, then we should call it now, to make sure - // that all the funcs in the .ctors section get run. - // Note: For ARM, we shouldn't have a .ctor section (should be empty) - // when we have an (pre)init_array section, but let's be compatible with - // old (non-eabi) binaries and try the _init (DT_INIT) anyway. if (si->init_func) { TRACE("[ %5d Calling init_func @ 0x%08x for '%s' ]\n", pid, (unsigned)si->init_func, si->name); @@ -1298,25 +1452,21 @@ static void call_constructors(soinfo *si) if (si->init_array) { TRACE("[ %5d Calling init_array @ 0x%08x [%d] for '%s' ]\n", pid, (unsigned)si->init_array, si->init_array_count, si->name); - call_array(si->init_array, si->init_array_count); + call_array(si->init_array, si->init_array_count, 0); TRACE("[ %5d Done calling init_array for '%s' ]\n", pid, si->name); } } + static void call_destructors(soinfo *si) { if (si->fini_array) { TRACE("[ %5d Calling fini_array @ 0x%08x [%d] for '%s' ]\n", pid, (unsigned)si->fini_array, si->fini_array_count, si->name); - call_array(si->fini_array, si->fini_array_count); + call_array(si->fini_array, si->fini_array_count, 1); TRACE("[ %5d Done calling fini_array for '%s' ]\n", pid, si->name); } - // If we have an fini section, then we should call it now, to make sure - // that all the funcs in the .dtors section get run. - // Note: For ARM, we shouldn't have a .dtor section (should be empty) - // when we have an fini_array section, but let's be compatible with - // old (non-eabi) binaries and try the _fini (DT_FINI) anyway. if (si->fini_func) { TRACE("[ %5d Calling fini_func @ 0x%08x for '%s' ]\n", pid, (unsigned)si->fini_func, si->name); @@ -1334,7 +1484,7 @@ static int nullify_closed_stdio (void) dev_null = open("/dev/null", O_RDWR); if (dev_null < 0) { - ERROR("Cannot open /dev/null.\n"); + DL_ERR("Cannot open /dev/null."); return -1; } TRACE("[ %5d Opened /dev/null file-descriptor=%d]\n", pid, dev_null); @@ -1360,7 +1510,7 @@ static int nullify_closed_stdio (void) /* The only error we allow is that the file descriptor does not exist, in which case we dup /dev/null to it. */ if (errno != EBADF) { - ERROR("nullify_stdio: unhandled error %s\n", strerror(errno)); + DL_ERR("nullify_stdio: unhandled error %s", strerror(errno)); return_value = -1; continue; } @@ -1371,9 +1521,9 @@ static int nullify_closed_stdio (void) do { status = dup2(dev_null, i); } while (status < 0 && errno == EINTR); - + if (status < 0) { - ERROR("nullify_stdio: dup2 error %s\n", strerror(errno)); + DL_ERR("nullify_stdio: dup2 error %s", strerror(errno)); return_value = -1; continue; } @@ -1382,12 +1532,12 @@ static int nullify_closed_stdio (void) /* If /dev/null is not one of the stdio file descriptors, close it. */ if (dev_null > 2) { TRACE("[ %5d Closing /dev/null file-descriptor=%d]\n", pid, dev_null); - do { + do { status = close(dev_null); } while (status < 0 && errno == EINTR); if (status < 0) { - ERROR("nullify_stdio: close error %s\n", strerror(errno)); + DL_ERR("nullify_stdio: close error %s", strerror(errno)); return_value = -1; } } @@ -1455,8 +1605,8 @@ static int link_image(soinfo *si, unsigned wr_offset) } } else if (phdr->p_type == PT_DYNAMIC) { if (si->dynamic != (unsigned *)-1) { - ERROR("%5d multiple PT_DYNAMIC segments found in '%s'. " - "Segment at 0x%08x, previously one found at 0x%08x\n", + DL_ERR("%5d multiple PT_DYNAMIC segments found in '%s'. " + "Segment at 0x%08x, previously one found at 0x%08x", pid, si->name, si->base + phdr->p_vaddr, (unsigned)si->dynamic); goto fail; @@ -1468,7 +1618,7 @@ static int link_image(soinfo *si, unsigned wr_offset) } if (si->dynamic == (unsigned *)-1) { - ERROR("%5d missing PT_DYNAMIC?!\n", pid); + DL_ERR("%5d missing PT_DYNAMIC?!", pid); goto fail; } @@ -1490,24 +1640,40 @@ static int link_image(soinfo *si, unsigned wr_offset) case DT_SYMTAB: si->symtab = (Elf32_Sym *) (si->base + *d); break; +#if !defined(ANDROID_SH_LINKER) case DT_PLTREL: if(*d != DT_REL) { - ERROR("DT_RELA not supported\n"); + DL_ERR("DT_RELA not supported"); goto fail; } break; +#endif +#ifdef ANDROID_SH_LINKER + case DT_JMPREL: + si->plt_rela = (Elf32_Rela*) (si->base + *d); + break; + case DT_PLTRELSZ: + si->plt_rela_count = *d / sizeof(Elf32_Rela); + break; +#else case DT_JMPREL: si->plt_rel = (Elf32_Rel*) (si->base + *d); break; case DT_PLTRELSZ: si->plt_rel_count = *d / 8; break; +#endif case DT_REL: si->rel = (Elf32_Rel*) (si->base + *d); break; case DT_RELSZ: si->rel_count = *d / 8; break; +#ifdef ANDROID_SH_LINKER + case DT_RELASZ: + si->rela_count = *d / sizeof(Elf32_Rela); + break; +#endif case DT_PLTGOT: /* Save this in case we decide to do lazy binding. We don't yet. */ si->plt_got = (unsigned *)(si->base + *d); @@ -1516,9 +1682,15 @@ static int link_image(soinfo *si, unsigned wr_offset) // Set the DT_DEBUG entry to the addres of _r_debug for GDB *d = (int) &_r_debug; break; +#ifdef ANDROID_SH_LINKER case DT_RELA: - ERROR("%5d DT_RELA not supported\n", pid); + si->rela = (Elf32_Rela *) (si->base + *d); + break; +#else + case DT_RELA: + DL_ERR("%5d DT_RELA not supported", pid); goto fail; +#endif case DT_INIT: si->init_func = (void (*)(void))(si->base + *d); DEBUG("%5d %s constructors (init func) found at %p\n", @@ -1569,16 +1741,18 @@ static int link_image(soinfo *si, unsigned wr_offset) pid, si->base, si->strtab, si->symtab); if((si->strtab == 0) || (si->symtab == 0)) { - ERROR("%5d missing essential tables\n", pid); + DL_ERR("%5d missing essential tables", pid); goto fail; } for(d = si->dynamic; *d; d += 2) { if(d[0] == DT_NEEDED){ DEBUG("%5d %s needs %s\n", pid, si->name, si->strtab + d[1]); - soinfo *lsi = find_library(si->strtab + d[1]); + soinfo *lsi = find_library(si->strtab + d[1]); if(lsi == 0) { - ERROR("%5d could not load '%s'\n", pid, si->strtab + d[1]); + strlcpy(tmp_err_buf, linker_get_error(), sizeof(tmp_err_buf)); + DL_ERR("%5d could not load needed library '%s' for '%s' (%s)", + pid, si->strtab + d[1], si->name, tmp_err_buf); goto fail; } lsi->refcount++; @@ -1596,6 +1770,19 @@ static int link_image(soinfo *si, unsigned wr_offset) goto fail; } +#ifdef ANDROID_SH_LINKER + if(si->plt_rela) { + DEBUG("[ %5d relocating %s plt ]\n", pid, si->name ); + if(reloc_library_a(si, si->plt_rela, si->plt_rela_count)) + goto fail; + } + if(si->rela) { + DEBUG("[ %5d relocating %s ]\n", pid, si->name ); + if(reloc_library_a(si, si->rela, si->rela_count)) + goto fail; + } +#endif /* ANDROID_SH_LINKER */ + si->flags |= FLAG_LINKED; DEBUG("[ %5d finished linking %s ]\n", pid, si->name); @@ -1643,6 +1830,29 @@ fail: return -1; } +static void parse_library_path(char *path, char *delim) +{ + size_t len; + char *ldpaths_bufp = ldpaths_buf; + int i = 0; + + len = strlcpy(ldpaths_buf, path, sizeof(ldpaths_buf)); + + while (i < LDPATH_MAX && (ldpaths[i] = strsep(&ldpaths_bufp, delim))) { + if (*ldpaths[i] != '\0') + ++i; + } + + /* Forget the last path if we had to truncate; this occurs if the 2nd to + * last char isn't '\0' (i.e. not originally a delim). */ + if (i > 0 && len >= sizeof(ldpaths_buf) && + ldpaths_buf[sizeof(ldpaths_buf) - 2] != '\0') { + ldpaths[i - 1] = NULL; + } else { + ldpaths[i] = NULL; + } +} + int main(int argc, char **argv) { return 0; @@ -1661,6 +1871,12 @@ unsigned __linker_init(unsigned **elfdata) unsigned *vecs = (unsigned*) (argv + argc + 1); soinfo *si; struct link_map * map; + char *ldpath_env = NULL; + + /* Setup a temporary TLS area that is used to get a working + * errno for system calls. + */ + __set_tls(__tls_area); pid = getpid(); @@ -1669,8 +1885,15 @@ unsigned __linker_init(unsigned **elfdata) gettimeofday(&t0, 0); #endif - __set_tls(__tls_area); - ((unsigned *)__get_tls())[TLS_SLOT_THREAD_ID] = gettid(); + /* NOTE: we store the elfdata pointer on a special location + * of the temporary TLS area in order to pass it to + * the C Library's runtime initializer. + * + * The initializer must clear the slot and reset the TLS + * to point to a different location to ensure that no other + * shared library constructor can access it. + */ + __tls_area[TLS_SLOT_BIONIC_PREINIT] = elfdata; debugger_init(); @@ -1678,6 +1901,8 @@ unsigned __linker_init(unsigned **elfdata) while(vecs[0] != 0) { if(!strncmp((char*) vecs[0], "DEBUG=", 6)) { debug_verbosity = atoi(((char*) vecs[0]) + 6); + } else if(!strncmp((char*) vecs[0], "LD_LIBRARY_PATH=", 16)) { + ldpath_env = (char*) vecs[0] + 16; } vecs++; } @@ -1737,8 +1962,14 @@ unsigned __linker_init(unsigned **elfdata) si->wrprotect_start = 0xffffffff; si->wrprotect_end = 0; - if(link_image(si, 0)){ - ERROR("CANNOT LINK EXECUTABLE '%s'\n", argv[0]); + /* Use LD_LIBRARY_PATH if we aren't setuid/setgid */ + if (ldpath_env && getuid() == geteuid() && getgid() == getegid()) + parse_library_path(ldpath_env, ":"); + + if(link_image(si, 0)) { + char errmsg[] = "CANNOT LINK EXECUTABLE\n"; + write(2, __linker_dl_err_buf, strlen(__linker_dl_err_buf)); + write(2, errmsg, sizeof(errmsg)); exit(-1); } |