X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=inline;f=src%2Fldso%2Fdynlink.c;h=1517281a838be2ae2c835fc7d0769708eae215fc;hb=e94d0692864ecf9522fd6a97610a47a2f718d3de;hp=6f23fa549ef705ed85e6063529c0327a177a3b1f;hpb=a897a20a57b461d388447858b9404fc81f107bcd;p=musl diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 6f23fa54..1517281a 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -7,12 +7,9 @@ #include #include #include -#include #include #include #include -#include -#include #include #include #include @@ -59,6 +56,7 @@ struct dso { Phdr *phdr; int phnum; + size_t phentsize; int refcnt; Sym *syms; uint32_t *hashtab; @@ -77,6 +75,7 @@ struct dso { char *rpath_orig, *rpath; void *tls_image; size_t tls_len, tls_size, tls_align, tls_id, tls_offset; + size_t relro_start, relro_end; void **new_dtv; unsigned char *new_tls; int new_dtv_idx, new_tls_idx; @@ -92,14 +91,14 @@ struct symdef { #include "reloc.h" -void __init_ssp(size_t *); -void *__install_initial_tls(void *); +int __init_tp(void *); void __init_libc(char **, char *); +const char *__libc_get_version(void); + static struct dso *head, *tail, *ldso, *fini_head; static char *env_path, *sys_path; static unsigned long long gencnt; -static int ssp_used; static int runtime; static int ldd_mode; static int ldso_fail; @@ -109,6 +108,7 @@ static pthread_rwlock_t lock; static struct debug debug; static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t); static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE }; +static long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)]; struct debug *_dl_debug_addr = &debug; @@ -199,13 +199,6 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def) { uint32_t h = 0, gh = 0; struct symdef def = {0}; - if (dso->ghashtab) { - gh = gnu_hash(s); - if (gh == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1; - } else { - h = sysv_hash(s); - if (h == 0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1; - } for (; dso; dso=dso->next) { Sym *sym; if (!dso->global) continue; @@ -254,7 +247,8 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri name = strings + sym->st_name; ctx = IS_COPY(type) ? head->next : head; def = find_sym(ctx, name, IS_PLT(type)); - if (!def.sym && sym->st_info>>4 != STB_WEAK) { + if (!def.sym && (sym->st_shndx != SHN_UNDEF + || sym->st_info>>4 != STB_WEAK)) { snprintf(errbuf, sizeof errbuf, "Error relocating %s: %s: symbol not found", dso->name, name); @@ -280,27 +274,32 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri * and "donate" them to the heap by setting up minimal malloc * structures and then freeing them. */ -static void reclaim(unsigned char *base, size_t start, size_t end) +static void reclaim(struct dso *dso, size_t start, size_t end) { size_t *a, *z; + if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end; + if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start; start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t); end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t); if (start>end || end-start < 4*sizeof(size_t)) return; - a = (size_t *)(base + start); - z = (size_t *)(base + end); + a = (size_t *)(dso->base + start); + z = (size_t *)(dso->base + end); a[-2] = 1; a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1; z[1] = 1; free(a); } -static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phcnt) +static void reclaim_gaps(struct dso *dso) { - for (; phcnt--; ph=(void *)((char *)ph+phent)) { + Phdr *ph = dso->phdr; + size_t phcnt = dso->phnum; + + for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) { if (ph->p_type!=PT_LOAD) continue; if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue; - reclaim(base, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr); - reclaim(base, ph->p_vaddr+ph->p_memsz, + reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr); + reclaim(dso, ph->p_vaddr+ph->p_memsz, ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE); } } @@ -343,13 +342,16 @@ static void *map_library(int fd, struct dso *dso) ph = ph0 = (void *)((char *)buf + eh->e_phoff); } for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) { - if (ph->p_type == PT_DYNAMIC) + if (ph->p_type == PT_DYNAMIC) { dyn = ph->p_vaddr; - if (ph->p_type == PT_TLS) { + } else if (ph->p_type == PT_TLS) { tls_image = ph->p_vaddr; dso->tls_align = ph->p_align; dso->tls_len = ph->p_filesz; dso->tls_size = ph->p_memsz; + } else if (ph->p_type == PT_GNU_RELRO) { + dso->relro_start = ph->p_vaddr & -PAGE_SIZE; + dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE; } if (ph->p_type != PT_LOAD) continue; if (ph->p_vaddr < addr_min) { @@ -393,6 +395,7 @@ static void *map_library(int fd, struct dso *dso) dso->phdr = (void *)(base + ph->p_vaddr + (eh->e_phoff-ph->p_offset)); dso->phnum = eh->e_phnum; + dso->phentsize = eh->e_phentsize; } /* Reuse the existing mapping for the lowest-address LOAD */ if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue; @@ -418,12 +421,12 @@ static void *map_library(int fd, struct dso *dso) goto error; break; } - if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum); dso->map = map; dso->map_len = map_len; dso->base = base; dso->dynv = (void *)(base+dyn); if (dso->tls_size) dso->tls_image = (void *)(base+tls_image); + if (!runtime) reclaim_gaps(dso); free(allocated_buf); return map; noexec: @@ -462,7 +465,9 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) } n = 0; s = p->rpath_orig; - while ((t=strstr(s, "$ORIGIN")) || (t=strstr(s, "${ORIGIN}"))) { + while ((t=strchr(s, '$'))) { + if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9)) + return -1; s = t+1; n++; } @@ -477,8 +482,10 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) * (either system paths or a call to dlopen). */ if (libc.secure) return -1; - if (readlink("/proc/self/exe", buf, buf_size) >= buf_size) + l = readlink("/proc/self/exe", buf, buf_size); + if (l >= buf_size) return -1; + buf[l] = 0; origin = buf; } else { origin = p->name; @@ -490,11 +497,13 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) d = p->rpath; s = p->rpath_orig; - while ((t=strstr(s, "$ORIGIN")) || (t=strstr(s, "${ORIGIN}"))) { + while ((t=strchr(s, '$'))) { memcpy(d, s, t-s); d += t-s; memcpy(d, origin, l); d += l; + /* It was determined previously that the '$' is followed + * either by "ORIGIN" or "{ORIGIN}". */ s = t + 7 + 2*(t[1]=='{'); } strcpy(d, s); @@ -608,6 +617,8 @@ static struct dso *load_library(const char *name, struct dso *needed_by) sys_path = ""; } fclose(f); + } else if (errno != ENOENT) { + sys_path = ""; } } if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib"; @@ -665,9 +676,10 @@ static struct dso *load_library(const char *name, struct dso *needed_by) /* Add a shortname only if name arg was not an explicit pathname. */ if (pathname != name) p->shortname = strrchr(p->name, '/')+1; if (p->tls_image) { - if (runtime && !__pthread_self_init()) { + if (runtime && !libc.has_thread_pointer) { munmap(map, p->map_len); free(p); + errno = ENOSYS; return 0; } p->tls_id = ++tls_cnt; @@ -756,22 +768,32 @@ static void reloc_all(struct dso *p) 2+(dyn[DT_PLTREL]==DT_RELA)); do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2); do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3); + + if (p->relro_start != p->relro_end && + mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) { + snprintf(errbuf, sizeof errbuf, + "Error relocating %s: RELRO protection failed: %m", + p->name); + if (runtime) longjmp(*rtld_fail, 1); + dprintf(2, "%s\n", errbuf); + ldso_fail = 1; + } + p->relocated = 1; } } -static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride) +static void kernel_mapped_dso(struct dso *p) { - for (; cnt--; ph = (void *)((char *)ph + stride)) - if (ph->p_type == PT_DYNAMIC) - return ph->p_vaddr; - return 0; -} - -static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p) -{ - size_t min_addr = -1, max_addr = 0; - for (; cnt--; ph = (void *)((char *)ph + stride)) { + size_t min_addr = -1, max_addr = 0, cnt; + Phdr *ph = p->phdr; + for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) { + if (ph->p_type == PT_DYNAMIC) { + p->dynv = (void *)(p->base + ph->p_vaddr); + } else if (ph->p_type == PT_GNU_RELRO) { + p->relro_start = ph->p_vaddr & -PAGE_SIZE; + p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE; + } if (ph->p_type != PT_LOAD) continue; if (ph->p_vaddr < min_addr) min_addr = ph->p_vaddr; @@ -782,6 +804,7 @@ static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p) max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE; p->map = p->base + min_addr; p->map_len = max_addr - min_addr; + p->kernel_mapped = 1; } static void do_fini() @@ -858,10 +881,13 @@ void *__copy_tls(unsigned char *mem) pthread_t td; struct dso *p; - if (!tls_cnt) return mem; - void **dtv = (void *)mem; dtv[0] = (void *)tls_cnt; + if (!tls_cnt) { + td = (void *)(dtv+1); + td->dtv = dtv; + return td; + } #ifdef TLS_ABOVE_TP mem += sizeof(void *) * (tls_cnt+1); @@ -954,6 +980,7 @@ void *__dynlink(int argc, char **argv) size_t vdso_base; size_t *auxv; char **envp = argv+argc+1; + void *initial_tls; /* Find aux vector just past environ[] */ for (i=argc+1; argv[i]; i++) @@ -972,6 +999,7 @@ void *__dynlink(int argc, char **argv) env_preload = 0; libc.secure = 1; } + libc.page_size = aux[AT_PAGESZ]; /* If the dynamic linker was invoked as a program itself, AT_BASE * will not be set. In that case, we assume the base address is @@ -987,13 +1015,11 @@ void *__dynlink(int argc, char **argv) lib->base = (void *)aux[AT_BASE]; lib->name = lib->shortname = "libc.so"; lib->global = 1; - lib->kernel_mapped = 1; ehdr = (void *)lib->base; lib->phnum = ehdr->e_phnum; lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff); - find_map_range(lib->phdr, ehdr->e_phnum, ehdr->e_phentsize, lib); - lib->dynv = (void *)(lib->base + find_dyn(lib->phdr, - ehdr->e_phnum, ehdr->e_phentsize)); + lib->phentsize = ehdr->e_phentsize; + kernel_mapped_dso(lib); decode_dyn(lib); if (aux[AT_PHDR]) { @@ -1002,6 +1028,7 @@ void *__dynlink(int argc, char **argv) /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */ app->phdr = phdr = (void *)aux[AT_PHDR]; app->phnum = aux[AT_PHNUM]; + app->phentsize = aux[AT_PHENT]; for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) { if (phdr->p_type == PT_PHDR) app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr); @@ -1016,12 +1043,12 @@ void *__dynlink(int argc, char **argv) } if (app->tls_size) app->tls_image = (char *)app->base + tls_image; if (interp_off) lib->name = (char *)app->base + interp_off; - app->name = argv[0]; - app->kernel_mapped = 1; - app->dynv = (void *)(app->base + find_dyn( - (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT])); - find_map_range((void *)aux[AT_PHDR], - aux[AT_PHNUM], aux[AT_PHENT], app); + if ((aux[0] & (1UL<name = (char *)aux[AT_EXECFN]; + else + app->name = argv[0]; + kernel_mapped_dso(app); } else { int fd; char *ldname = argv[0]; @@ -1030,8 +1057,11 @@ void *__dynlink(int argc, char **argv) *argv++ = (void *)-1; if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1; if (!argv[0]) { - dprintf(2, "musl libc/dynamic program loader\n"); - dprintf(2, "usage: %s pathname%s\n", ldname, + dprintf(2, "musl libc\n" + "Version %s\n" + "Dynamic Program Loader\n" + "Usage: %s [--] pathname%s\n", + __libc_get_version(), ldname, ldd_mode ? "" : " [args]"); _exit(1); } @@ -1084,6 +1114,7 @@ void *__dynlink(int argc, char **argv) ehdr = (void *)vdso_base; vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff); vdso->phnum = ehdr->e_phnum; + vdso->phentsize = ehdr->e_phentsize; for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) { if (phdr->p_type == PT_DYNAMIC) vdso->dynv = (void *)(vdso_base + phdr->p_offset); @@ -1111,10 +1142,8 @@ void *__dynlink(int argc, char **argv) /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */ /* Donate unused parts of app and library mapping to malloc */ - reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]); - ehdr = (void *)lib->base; - reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff), - ehdr->e_phentsize, ehdr->e_phnum); + reclaim_gaps(app); + reclaim_gaps(lib); /* Load preload/needed libraries, add their symbols to the global * namespace, and perform all remaining relocations. The main @@ -1124,19 +1153,29 @@ void *__dynlink(int argc, char **argv) load_deps(app); make_global(app); +#ifndef DYNAMIC_IS_RO + for (i=0; app->dynv[i]; i+=2) + if (app->dynv[i]==DT_DEBUG) + app->dynv[i+1] = (size_t)&debug; +#endif + reloc_all(app->next); reloc_all(app); update_tls_size(); - if (tls_cnt) { - void *mem = mmap(0, libc.tls_size, PROT_READ|PROT_WRITE, - MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); - if (mem==MAP_FAILED || - !__install_initial_tls(__copy_tls(mem))) { + if (libc.tls_size > sizeof builtin_tls) { + initial_tls = calloc(libc.tls_size, 1); + if (!initial_tls) { dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n", argv[0], libc.tls_size); _exit(127); } + } else { + initial_tls = builtin_tls; + } + if (__init_tp(__copy_tls(initial_tls)) < 0 && tls_cnt) { + dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]); + _exit(127); } if (ldso_fail) _exit(127); @@ -1148,11 +1187,6 @@ void *__dynlink(int argc, char **argv) * all memory used by the dynamic linker. */ runtime = 1; -#ifndef DYNAMIC_IS_RO - for (i=0; app->dynv[i]; i+=2) - if (app->dynv[i]==DT_DEBUG) - app->dynv[i+1] = (size_t)&debug; -#endif debug.ver = 1; debug.bp = _dl_debug_state; debug.head = head; @@ -1160,7 +1194,6 @@ void *__dynlink(int argc, char **argv) debug.state = 0; _dl_debug_state(); - if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]); __init_libc(envp, argv[0]); atexit(do_fini); errno = 0; @@ -1210,7 +1243,7 @@ void *dlopen(const char *file, int mode) p = 0; errflag = 1; goto end; - } else p = load_library(file, 0); + } else p = load_library(file, head); if (!p) { snprintf(errbuf, sizeof errbuf, noload ? @@ -1242,9 +1275,6 @@ void *dlopen(const char *file, int mode) } update_tls_size(); - - if (ssp_used) __init_ssp(libc.auxv); - _dl_debug_state(); orig_tail = tail; end: @@ -1316,7 +1346,7 @@ failed: return 0; } -int __dladdr(void *addr, Dl_info *info) +int __dladdr(const void *addr, Dl_info *info) { struct dso *p; Sym *sym; @@ -1341,7 +1371,7 @@ int __dladdr(void *addr, Dl_info *info) uint32_t *hashval; buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4); sym += p->ghashtab[1]; - for (i = 0; i < p->ghashtab[0]; i++) { + for (i = nsym = 0; i < p->ghashtab[0]; i++) { if (buckets[i] > nsym) nsym = buckets[i]; } @@ -1426,7 +1456,7 @@ void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) { return 0; } -int __dladdr (void *addr, Dl_info *info) +int __dladdr (const void *addr, Dl_info *info) { return 0; }