X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=d7d6800238fea88d161ebdc2ac0ea8dc0b3cf167;hp=263593ab75531e45e9d3f04f5f5740f68c611220;hb=2bd05a4fc26c297754f7ee5745a1c3b072a44b7d;hpb=d93e028c6bbd491592313fc77e056f6424ea4668 diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 263593ab..d7d68002 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -20,9 +20,7 @@ static int errflag; static char errbuf[128]; -#ifdef __PIC__ - -#include "reloc.h" +#ifdef SHARED #if ULONG_MAX == 0xffffffff typedef Elf32_Ehdr Ehdr; @@ -55,6 +53,7 @@ struct dso { int refcnt; Sym *syms; uint32_t *hashtab; + uint32_t *ghashtab; char *strings; unsigned char *map; size_t map_len; @@ -68,6 +67,8 @@ struct dso { char buf[]; }; +#include "reloc.h" + void __init_ssp(size_t *); static struct dso *head, *tail, *libc; @@ -76,6 +77,7 @@ static int rtld_used; static int ssp_used; static int runtime; static int ldd_mode; +static int ldso_fail; static jmp_buf rtld_fail; static pthread_rwlock_t lock; static struct debug debug; @@ -94,7 +96,15 @@ static void decode_vec(size_t *v, size_t *a, size_t cnt) } } -static uint32_t hash(const char *s0) +static int search_vec(size_t *v, size_t *r, size_t key) +{ + for (; v[0]!=key; v+=2) + if (!v[0]) return 0; + *r = v[1]; + return 1; +} + +static uint32_t sysv_hash(const char *s0) { const unsigned char *s = (void *)s0; uint_fast32_t h = 0; @@ -105,9 +115,21 @@ static uint32_t hash(const char *s0) return h & 0xfffffff; } -static Sym *lookup(const char *s, uint32_t h, Sym *syms, uint32_t *hashtab, char *strings) +static uint32_t gnu_hash(const char *s0) +{ + const unsigned char *s = (void *)s0; + uint_fast32_t h = 5381; + for (; *s; s++) + h = h*33 + *s; + return h; +} + +static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso) { size_t i; + Sym *syms = dso->syms; + 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)) return syms+i; @@ -115,20 +137,61 @@ static Sym *lookup(const char *s, uint32_t h, Sym *syms, uint32_t *hashtab, char return 0; } +static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso) +{ + Sym *sym; + char *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]; + + if (!n) return 0; + + strings = dso->strings; + sym = dso->syms + n; + hashval = buckets + nbuckets + (n - hashtab[1]); + + for (h1 |= 1; ; sym++) { + h2 = *hashval++; + if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name)) + return sym; + if (h2 & 1) break; + } + + return 0; +} + #define OK_TYPES (1<ghashtab) { + gh = gnu_hash(s); + if (gh == 0xf9040207 && !strcmp(s, "dlopen")) rtld_used = 1; + if (gh == 0xf4dc4ae && !strcmp(s, "dlsym")) rtld_used = 1; + if (gh == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1; + } else { + h = sysv_hash(s); + if (h == 0x6b366be && !strcmp(s, "dlopen")) rtld_used = 1; + if (h == 0x6b3afd && !strcmp(s, "dlsym")) rtld_used = 1; + if (h == 0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1; + } for (; dso; dso=dso->next) { Sym *sym; if (!dso->global) continue; - sym = lookup(s, h, dso->syms, dso->hashtab, dso->strings); + if (dso->ghashtab) { + if (!gh) gh = gnu_hash(s); + sym = gnu_lookup(s, gh, dso); + } else { + if (!h) h = sysv_hash(s); + sym = sysv_lookup(s, h, dso); + } if (sym && (!need_def || sym->st_shndx) && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES) && (1<<(sym->st_info>>4) & OK_BINDS)) { @@ -140,8 +203,11 @@ static void *find_sym(struct dso *dso, const char *s, int need_def) return def; } -static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t stride, Sym *syms, char *strings, struct dso *dso) +static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride) { + unsigned char *base = dso->base; + Sym *syms = dso->syms; + char *strings = dso->strings; Sym *sym; const char *name; size_t sym_val, sym_size; @@ -157,7 +223,7 @@ static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t if (sym_index) { sym = syms + sym_index; name = strings + sym->st_name; - ctx = IS_COPY(type) ? dso->next : dso; + ctx = IS_COPY(type) ? head->next : head; sym_val = (size_t)find_sym(ctx, name, IS_PLT(type)); if (!sym_val && sym->st_info>>4 != STB_WEAK) { snprintf(errbuf, sizeof errbuf, @@ -165,9 +231,12 @@ static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t dso->name, name); if (runtime) longjmp(rtld_fail, 1); dprintf(2, "%s\n", errbuf); - _exit(127); + ldso_fail = 1; + continue; } sym_size = sym->st_size; + } else { + sym_val = sym_size = 0; } do_single_reloc(reloc_addr, type, sym_val, sym_size, base, rel[2]); } @@ -315,13 +384,17 @@ static void decode_dyn(struct dso *p) size_t dyn[DYN_CNT] = {0}; decode_vec(p->dynv, dyn, DYN_CNT); p->syms = (void *)(p->base + dyn[DT_SYMTAB]); - p->hashtab = (void *)(p->base + dyn[DT_HASH]); p->strings = (void *)(p->base + dyn[DT_STRTAB]); + if (dyn[0]&(1<hashtab = (void *)(p->base + dyn[DT_HASH]); + if (search_vec(p->dynv, dyn, DT_GNU_HASH)) + p->ghashtab = (void *)(p->base + *dyn); } static struct dso *load_library(const char *name) { char buf[2*NAME_MAX+2]; + const char *pathname; unsigned char *base, *map; size_t dyno, map_len; struct dso *p; @@ -346,16 +419,17 @@ static struct dso *load_library(const char *name) } } } - /* Search for the name to see if it's already loaded */ - for (p=head->next; p; p=p->next) { - if (!strcmp(p->shortname, name)) { - p->refcnt++; - return p; - } - } if (strchr(name, '/')) { + pathname = name; fd = open(name, O_RDONLY); } else { + /* Search for the name to see if it's already loaded */ + for (p=head->next; p; p=p->next) { + if (p->shortname && !strcmp(p->shortname, name)) { + p->refcnt++; + return p; + } + } if (strlen(name) > NAME_MAX) return 0; fd = -1; if (r_path) fd = path_open(name, r_path, buf, sizeof buf); @@ -372,6 +446,7 @@ static struct dso *load_library(const char *name) if (sys_path) fd = path_open(name, sys_path, buf, sizeof buf); else fd = path_open(name, "/lib:/usr/local/lib:/usr/lib", buf, sizeof buf); } + pathname = buf; } if (fd < 0) return 0; if (fstat(fd, &st) < 0) { @@ -380,6 +455,10 @@ static struct dso *load_library(const char *name) } for (p=head->next; p; p=p->next) { if (p->dev == st.st_dev && p->ino == st.st_ino) { + /* If this library was previously loaded with a + * pathname but a search found the same inode, + * setup its shortname so it can be found by name. */ + if (!p->shortname) p->shortname = strrchr(p->name, '/')+1; close(fd); p->refcnt++; return p; @@ -388,7 +467,7 @@ static struct dso *load_library(const char *name) map = map_library(fd, &map_len, &base, &dyno); close(fd); if (!map) return 0; - p = calloc(1, sizeof *p + strlen(buf) + 1); + p = calloc(1, sizeof *p + strlen(pathname) + 1); if (!p) { munmap(map, map_len); return 0; @@ -404,15 +483,15 @@ static struct dso *load_library(const char *name) p->ino = st.st_ino; p->refcnt = 1; p->name = p->buf; - strcpy(p->name, buf); - if (!strchr(name, '/')) p->shortname = strrchr(p->name, '/'); - if (!p->shortname) p->shortname = p->name; + strcpy(p->name, pathname); + /* Add a shortname only if name arg was not an explicit pathname. */ + if (pathname != name) p->shortname = strrchr(p->name, '/')+1; tail->next = p; p->prev = tail; tail = p; - if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, buf, base); + if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, base); return p; } @@ -435,7 +514,8 @@ static void load_deps(struct dso *p) p->strings + p->dynv[i+1], p->name); if (runtime) longjmp(rtld_fail, 1); dprintf(2, "%s\n", errbuf); - _exit(127); + ldso_fail = 1; + continue; } if (runtime) { tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2)); @@ -474,12 +554,13 @@ static void reloc_all(struct dso *p) for (; p; p=p->next) { if (p->relocated) continue; decode_vec(p->dynv, dyn, DYN_CNT); - do_relocs(p->base, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ], - 2+(dyn[DT_PLTREL]==DT_RELA), p->syms, p->strings, head); - do_relocs(p->base, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], - 2, p->syms, p->strings, head); - do_relocs(p->base, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], - 3, p->syms, p->strings, head); +#ifdef NEED_ARCH_RELOCS + do_arch_relocs(p, head); +#endif + do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ], + 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); p->relocated = 1; } } @@ -570,13 +651,17 @@ void *__dynlink(int argc, char **argv) decode_dyn(lib); if (aux[AT_PHDR]) { + size_t interp_off = 0; /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */ phdr = (void *)aux[AT_PHDR]; 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); + else if (phdr->p_type == PT_INTERP) + interp_off = (size_t)phdr->p_vaddr; } - app->name = app->shortname = argv[0]; + if (interp_off) lib->name = (char *)app->base + interp_off; + app->name = argv[0]; app->dynv = (void *)(app->base + find_dyn( (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT])); } else { @@ -605,7 +690,8 @@ void *__dynlink(int argc, char **argv) } runtime = 0; close(fd); - app->name = app->shortname = argv[0]; + lib->name = ldname; + app->name = argv[0]; app->dynv = (void *)(app->base + dyno); aux[AT_ENTRY] = ehdr->e_entry; } @@ -661,6 +747,7 @@ void *__dynlink(int argc, char **argv) reloc_all(app->next); reloc_all(app); + if (ldso_fail) _exit(127); if (ldd_mode) _exit(0); /* Switch to runtime mode: any further failures in the dynamic @@ -669,9 +756,11 @@ 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; @@ -761,7 +850,7 @@ end: static void *do_dlsym(struct dso *p, const char *s, void *ra) { size_t i; - uint32_t h; + uint32_t h = 0, gh = 0; Sym *sym; if (p == RTLD_NEXT) { for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next); @@ -775,13 +864,23 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra) if (!res) goto failed; return res; } - h = hash(s); - sym = lookup(s, h, p->syms, p->hashtab, p->strings); + if (p->ghashtab) { + gh = gnu_hash(s); + sym = gnu_lookup(s, gh, p); + } else { + h = sysv_hash(s); + sym = sysv_lookup(s, h, p); + } if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) return p->base + sym->st_value; if (p->deps) for (i=0; p->deps[i]; i++) { - sym = lookup(s, h, p->deps[i]->syms, - p->deps[i]->hashtab, p->deps[i]->strings); + if (p->deps[i]->ghashtab) { + if (!gh) gh = gnu_hash(s); + sym = gnu_lookup(s, h, p->deps[i]); + } else { + if (!h) h = sysv_hash(s); + sym = sysv_lookup(s, h, p->deps[i]); + } if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) return p->deps[i]->base + sym->st_value; }