X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=a1bdf0fb1b3182494abef08e4f57aa096ed323cd;hb=7ee48f7b69523c68768684551bc37ba05496c27f;hp=fa5ad004a41b0861d8dc90bb5e1a43e5ed6bbcec;hpb=7c6c290695cb8726e876ff4fb8413913f661fc0b;p=musl diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index fa5ad004..a1bdf0fb 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 @@ -63,6 +60,7 @@ struct dso { Sym *syms; uint32_t *hashtab; uint32_t *ghashtab; + int16_t *versym; char *strings; unsigned char *map; size_t map_len; @@ -71,7 +69,9 @@ struct dso { signed char global; char relocated; char constructed; - struct dso **deps; + char kernel_mapped; + struct dso **deps, *needed_by; + char *rpath_orig, *rpath; void *tls_image; size_t tls_len, tls_size, tls_align, tls_id, tls_offset; void **new_dtv; @@ -93,8 +93,10 @@ void __init_ssp(size_t *); void *__install_initial_tls(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, *r_path; +static char *env_path, *sys_path; static unsigned long long gencnt; static int ssp_used; static int runtime; @@ -156,7 +158,8 @@ static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso) uint32_t *hashtab = dso->hashtab; char *strings = dso->strings; for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) { - if (!strcmp(s, strings+syms[i].st_name)) + if ((!dso->versym || dso->versym[i] >= 0) + && (!strcmp(s, strings+syms[i].st_name))) return syms+i; } return 0; @@ -164,25 +167,24 @@ static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso) static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso) { - Sym *sym; - char *strings; + Sym *syms = dso->syms; + char *strings = dso->strings; uint32_t *hashtab = dso->ghashtab; uint32_t nbuckets = hashtab[0]; uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4); uint32_t h2; uint32_t *hashval; - uint32_t n = buckets[h1 % nbuckets]; + uint32_t i = buckets[h1 % nbuckets]; - if (!n) return 0; + if (!i) return 0; - strings = dso->strings; - sym = dso->syms + n; - hashval = buckets + nbuckets + (n - hashtab[1]); + hashval = buckets + nbuckets + (i - hashtab[1]); - for (h1 |= 1; ; sym++) { + for (h1 |= 1; ; i++) { h2 = *hashval++; - if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name)) - return sym; + if ((!dso->versym || dso->versym[i] >= 0) + && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name)) + return syms+i; if (h2 & 1) break; } @@ -251,7 +253,8 @@ 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); @@ -446,6 +449,64 @@ static int path_open(const char *name, const char *s, char *buf, size_t buf_size } } +static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) +{ + size_t n, l; + const char *s, *t, *origin; + char *d; + if (p->rpath) return 0; + if (!p->rpath_orig) return -1; + if (!strchr(p->rpath_orig, '$')) { + p->rpath = p->rpath_orig; + return 0; + } + n = 0; + s = p->rpath_orig; + while ((t=strchr(s, '$'))) { + if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9)) + return -1; + s = t+1; + n++; + } + if (n > SSIZE_MAX/PATH_MAX) return -1; + + if (p->kernel_mapped) { + /* $ORIGIN searches cannot be performed for the main program + * when it is suid/sgid/AT_SECURE. This is because the + * pathname is under the control of the caller of execve. + * For libraries, however, $ORIGIN can be processed safely + * since the library's pathname came from a trusted source + * (either system paths or a call to dlopen). */ + if (libc.secure) + return -1; + l = readlink("/proc/self/exe", buf, buf_size); + if (l >= buf_size) + return -1; + buf[l] = 0; + origin = buf; + } else { + origin = p->name; + } + t = strrchr(origin, '/'); + l = t ? t-origin : 0; + p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1); + if (!p->rpath) return -1; + + d = p->rpath; + s = p->rpath_orig; + while ((t=strchr(s, '$'))) { + 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); + return 0; +} + static void decode_dyn(struct dso *p) { size_t dyn[DYN_CNT] = {0}; @@ -454,11 +515,15 @@ static void decode_dyn(struct dso *p) p->strings = (void *)(p->base + dyn[DT_STRTAB]); if (dyn[0]&(1<hashtab = (void *)(p->base + dyn[DT_HASH]); + if (dyn[0]&(1<rpath_orig = (void *)(p->strings + dyn[DT_RPATH]); if (search_vec(p->dynv, dyn, DT_GNU_HASH)) p->ghashtab = (void *)(p->base + *dyn); + if (search_vec(p->dynv, dyn, DT_VERSYM)) + p->versym = (void *)(p->base + *dyn); } -static struct dso *load_library(const char *name) +static struct dso *load_library(const char *name, struct dso *needed_by) { char buf[2*NAME_MAX+2]; const char *pathname; @@ -518,7 +583,9 @@ static struct dso *load_library(const char *name) if (strlen(name) > NAME_MAX) return 0; fd = -1; if (env_path) fd = path_open(name, env_path, buf, sizeof buf); - if (fd < 0 && r_path) fd = path_open(name, r_path, buf, sizeof buf); + for (p=needed_by; fd < 0 && p; p=p->needed_by) + if (!fixup_rpath(p, buf, sizeof buf)) + fd = path_open(name, p->rpath, buf, sizeof buf); if (fd < 0) { if (!sys_path) { char *prefix = 0; @@ -547,6 +614,8 @@ static struct dso *load_library(const char *name) sys_path = ""; } fclose(f); + } else if (errno != ENOENT) { + sys_path = ""; } } if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib"; @@ -598,6 +667,7 @@ static struct dso *load_library(const char *name) p->dev = st.st_dev; p->ino = st.st_ino; p->refcnt = 1; + p->needed_by = needed_by; p->name = p->buf; strcpy(p->name, pathname); /* Add a shortname only if name arg was not an explicit pathname. */ @@ -639,13 +709,9 @@ static void load_deps(struct dso *p) size_t i, ndeps=0; struct dso ***deps = &p->deps, **tmp, *dep; for (; p; p=p->next) { - for (i=0; p->dynv[i]; i+=2) { - if (p->dynv[i] != DT_RPATH) continue; - r_path = (void *)(p->strings + p->dynv[i+1]); - } for (i=0; p->dynv[i]; i+=2) { if (p->dynv[i] != DT_NEEDED) continue; - dep = load_library(p->strings + p->dynv[i+1]); + dep = load_library(p->strings + p->dynv[i+1], p); if (!dep) { snprintf(errbuf, sizeof errbuf, "Error loading shared library %s: %m (needed by %s)", @@ -663,7 +729,6 @@ static void load_deps(struct dso *p) *deps = tmp; } } - r_path = 0; } } @@ -676,7 +741,7 @@ static void load_preload(char *s) for (z=s; *z && !isspace(*z); z++); tmp = *z; *z = 0; - load_library(s); + load_library(s, 0); *z = tmp; } } @@ -913,7 +978,9 @@ void *__dynlink(int argc, char **argv) || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) { env_path = 0; 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 @@ -929,6 +996,7 @@ 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); @@ -957,7 +1025,12 @@ 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]; + if ((aux[0] & (1UL<name = (char *)aux[AT_EXECFN]; + else + 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], @@ -970,8 +1043,11 @@ 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); } @@ -1150,7 +1226,7 @@ void *dlopen(const char *file, int mode) p = 0; errflag = 1; goto end; - } else p = load_library(file); + } else p = load_library(file, head); if (!p) { snprintf(errbuf, sizeof errbuf, noload ? @@ -1256,7 +1332,7 @@ failed: return 0; } -int __dladdr(void *addr, Dl_info *info) +int __dladdr(const void *addr, Dl_info *info) { struct dso *p; Sym *sym; @@ -1281,7 +1357,7 @@ 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]; } @@ -1366,7 +1442,7 @@ 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; }