X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ldso%2Fdynlink.c;h=7ac0bf7552bc2aac596ec6ffb24f23217714202a;hb=d0209a2a334ff714063b70dc69c1fea131304836;hp=025ed1b0c81eae20d5b01593393c17931b23d944;hpb=ba18c1ecc6a18203ad8496791154af86f706f632;p=musl diff --git a/ldso/dynlink.c b/ldso/dynlink.c index 025ed1b0..7ac0bf75 100644 --- a/ldso/dynlink.c +++ b/ldso/dynlink.c @@ -1,4 +1,5 @@ #define _GNU_SOURCE +#define SYSCALL_NO_TLS 1 #include #include #include @@ -29,6 +30,9 @@ static void error(const char *, ...); #define MAXP2(a,b) (-(-(a)&-(b))) #define ALIGN(x,y) ((x)+(y)-1 & -(y)) +#define container_of(p,t,m) ((t*)((char *)(p)-offsetof(t,m))) +#define countof(a) ((sizeof (a))/(sizeof (a)[0])) + struct debug { int ver; void *head; @@ -69,14 +73,19 @@ struct dso { char relocated; char constructed; char kernel_mapped; + char mark; + char bfs_built; + char runtime_loaded; struct dso **deps, *needed_by; + size_t ndeps_direct; + size_t next_dep; + int ctor_visitor; char *rpath_orig, *rpath; struct tls_module tls; size_t tls_id; size_t relro_start, relro_end; uintptr_t *new_dtv; unsigned char *new_tls; - volatile int new_dtv_idx, new_tls_idx; struct td_index *td_index; struct dso *fini_next; char *shortname; @@ -116,16 +125,21 @@ static int runtime; static int ldd_mode; static int ldso_fail; static int noload; +static int shutting_down; static jmp_buf *rtld_fail; static pthread_rwlock_t lock; static struct debug debug; static struct tls_module *tls_tail; static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN; static size_t static_tls_cnt; -static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE }; +static pthread_mutex_t init_fini_lock; +static pthread_cond_t ctor_cond; +static struct dso *builtin_deps[2]; +static struct dso *const no_deps[1]; +static struct dso *builtin_ctor_queue[4]; +static struct dso **main_ctor_queue; static struct fdpic_loadmap *app_loadmap; static struct fdpic_dummy_loadmap app_dummy_loadmap; -static struct dso *const nodeps_dummy; struct debug *_dl_debug_addr = &debug; @@ -269,12 +283,16 @@ static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, #define ARCH_SYM_REJECT_UND(s) 0 #endif -static struct symdef find_sym(struct dso *dso, const char *s, int need_def) +#if defined(__GNUC__) +__attribute__((always_inline)) +#endif +static inline struct symdef find_sym2(struct dso *dso, const char *s, int need_def, int use_deps) { uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght; size_t ghm = 1ul << gh % (8*sizeof(size_t)); struct symdef def = {0}; - for (; dso; dso=dso->syms_next) { + struct dso **deps = use_deps ? dso->deps : 0; + for (; dso; dso=use_deps ? *deps++ : dso->syms_next) { Sym *sym; if ((ght = dso->ghashtab)) { sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm); @@ -299,6 +317,11 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def) return def; } +static struct symdef find_sym(struct dso *dso, const char *s, int need_def) +{ + return find_sym2(dso, s, need_def, 0); +} + static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride) { unsigned char *base = dso->base; @@ -349,7 +372,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri sym = syms + sym_index; name = strings + sym->st_name; ctx = type==REL_COPY ? head->syms_next : head; - def = (sym->st_info&0xf) == STT_SECTION + def = (sym->st_info>>4) == STB_LOCAL ? (struct symdef){ .dso = dso, .sym = sym } : find_sym(ctx, name, type==REL_PLT); if (!def.sym && (sym->st_shndx != SHN_UNDEF @@ -376,7 +399,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri tls_val = def.sym ? def.sym->st_value : 0; if ((type == REL_TPOFF || type == REL_TPOFF_NEG) - && runtime && def.dso->tls_id > static_tls_cnt) { + && def.dso->tls_id > static_tls_cnt) { error("Error relocating %s: %s: initial-exec TLS " "resolves to dynamic definition in %s", dso->name, name, def.dso->name); @@ -393,6 +416,9 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri case REL_PLT: *reloc_addr = sym_val + addend; break; + case REL_USYMBOLIC: + memcpy(reloc_addr, &(size_t){sym_val + addend}, sizeof(size_t)); + break; case REL_RELATIVE: *reloc_addr = (size_t)base + addend; break; @@ -436,7 +462,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri #endif case REL_TLSDESC: if (stride<3) addend = reloc_addr[1]; - if (runtime && def.dso->tls_id > static_tls_cnt) { + if (def.dso->tls_id > static_tls_cnt) { struct td_index *new = malloc(sizeof *new); if (!new) { error( @@ -906,7 +932,7 @@ static void *dl_mmap(size_t n) #else p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0); #endif - return p == MAP_FAILED ? 0 : p; + return (unsigned long)p > -4096UL ? 0 : p; } static void makefuncdescs(struct dso *p) @@ -1103,6 +1129,7 @@ static struct dso *load_library(const char *name, struct dso *needed_by) p->ino = st.st_ino; p->needed_by = needed_by; p->name = p->buf; + p->runtime_loaded = runtime; 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; @@ -1110,9 +1137,9 @@ static struct dso *load_library(const char *name, struct dso *needed_by) p->tls_id = ++tls_cnt; tls_align = MAXP2(tls_align, p->tls.align); #ifdef TLS_ABOVE_TP - p->tls.offset = tls_offset + ( (tls_align-1) & - -(tls_offset + (uintptr_t)p->tls.image) ); - tls_offset += p->tls.size; + p->tls.offset = tls_offset + ( (p->tls.align-1) & + (-tls_offset + (uintptr_t)p->tls.image) ); + tls_offset = p->tls.offset + p->tls.size; #else tls_offset += p->tls.size + p->tls.align - 1; tls_offset -= (tls_offset + (uintptr_t)p->tls.image) @@ -1138,30 +1165,99 @@ static struct dso *load_library(const char *name, struct dso *needed_by) return p; } +static void load_direct_deps(struct dso *p) +{ + size_t i, cnt=0; + + if (p->deps) return; + /* For head, all preloads are direct pseudo-dependencies. + * Count and include them now to avoid realloc later. */ + if (p==head) for (struct dso *q=p->next; q; q=q->next) + cnt++; + for (i=0; p->dynv[i]; i+=2) + if (p->dynv[i] == DT_NEEDED) cnt++; + /* Use builtin buffer for apps with no external deps, to + * preserve property of no runtime failure paths. */ + p->deps = (p==head && cnt<2) ? builtin_deps : + calloc(cnt+1, sizeof *p->deps); + if (!p->deps) { + error("Error loading dependencies for %s", p->name); + if (runtime) longjmp(*rtld_fail, 1); + } + cnt=0; + if (p==head) for (struct dso *q=p->next; q; q=q->next) + p->deps[cnt++] = q; + for (i=0; p->dynv[i]; i+=2) { + if (p->dynv[i] != DT_NEEDED) continue; + struct dso *dep = load_library(p->strings + p->dynv[i+1], p); + if (!dep) { + error("Error loading shared library %s: %m (needed by %s)", + p->strings + p->dynv[i+1], p->name); + if (runtime) longjmp(*rtld_fail, 1); + continue; + } + p->deps[cnt++] = dep; + } + p->deps[cnt] = 0; + p->ndeps_direct = cnt; +} + 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_NEEDED) continue; - dep = load_library(p->strings + p->dynv[i+1], p); - if (!dep) { - error("Error loading shared library %s: %m (needed by %s)", - p->strings + p->dynv[i+1], p->name); - if (runtime) longjmp(*rtld_fail, 1); - continue; - } - if (runtime) { - tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2)); - if (!tmp) longjmp(*rtld_fail, 1); - tmp[ndeps++] = dep; - tmp[ndeps] = 0; - *deps = tmp; - } + if (p->deps) return; + for (; p; p=p->next) + load_direct_deps(p); +} + +static void extend_bfs_deps(struct dso *p) +{ + size_t i, j, cnt, ndeps_all; + struct dso **tmp; + + /* Can't use realloc if the original p->deps was allocated at + * program entry and malloc has been replaced, or if it's + * the builtin non-allocated trivial main program deps array. */ + int no_realloc = (__malloc_replaced && !p->runtime_loaded) + || p->deps == builtin_deps; + + if (p->bfs_built) return; + ndeps_all = p->ndeps_direct; + + /* Mark existing (direct) deps so they won't be duplicated. */ + for (i=0; p->deps[i]; i++) + p->deps[i]->mark = 1; + + /* For each dependency already in the list, copy its list of direct + * dependencies to the list, excluding any items already in the + * list. Note that the list this loop iterates over will grow during + * the loop, but since duplicates are excluded, growth is bounded. */ + for (i=0; p->deps[i]; i++) { + struct dso *dep = p->deps[i]; + for (j=cnt=0; jndeps_direct; j++) + if (!dep->deps[j]->mark) cnt++; + tmp = no_realloc ? + malloc(sizeof(*tmp) * (ndeps_all+cnt+1)) : + realloc(p->deps, sizeof(*tmp) * (ndeps_all+cnt+1)); + if (!tmp) { + error("Error recording dependencies for %s", p->name); + if (runtime) longjmp(*rtld_fail, 1); + continue; } + if (no_realloc) { + memcpy(tmp, p->deps, sizeof(*tmp) * (ndeps_all+1)); + no_realloc = 0; + } + p->deps = tmp; + for (j=0; jndeps_direct; j++) { + if (dep->deps[j]->mark) continue; + dep->deps[j]->mark = 1; + p->deps[ndeps_all++] = dep->deps[j]; + } + p->deps[ndeps_all] = 0; } - if (!*deps) *deps = (struct dso **)&nodeps_dummy; + p->bfs_built = 1; + for (p=head; p; p=p->next) + p->mark = 0; } static void load_preload(char *s) @@ -1277,7 +1373,18 @@ void __libc_exit_fini() { struct dso *p; size_t dyn[DYN_CNT]; + int self = __pthread_self()->tid; + + /* Take both locks before setting shutting_down, so that + * either lock is sufficient to read its value. The lock + * order matches that in dlopen to avoid deadlock. */ + pthread_rwlock_wrlock(&lock); + pthread_mutex_lock(&init_fini_lock); + shutting_down = 1; + pthread_rwlock_unlock(&lock); for (p=fini_head; p; p=p->fini_next) { + while (p->ctor_visitor && p->ctor_visitor!=self) + pthread_cond_wait(&ctor_cond, &init_fini_lock); if (!p->constructed) continue; decode_vec(p->dynv, dyn, DYN_CNT); if (dyn[0] & (1<prev) { - if (p->constructed) continue; - p->constructed = 1; + size_t cnt, qpos, spos, i; + struct dso *p, **queue, **stack; + + if (ldd_mode) return 0; + + /* Bound on queue size is the total number of indirect deps. + * If a bfs deps list was built, we can use it. Otherwise, + * bound by the total number of DSOs, which is always safe and + * is reasonable we use it (for main app at startup). */ + if (dso->bfs_built) { + for (cnt=0; dso->deps[cnt]; cnt++) + dso->deps[cnt]->mark = 0; + cnt++; /* self, not included in deps */ + } else { + for (cnt=0, p=head; p; cnt++, p=p->next) + p->mark = 0; + } + cnt++; /* termination slot */ + if (dso==head && cnt <= countof(builtin_ctor_queue)) + queue = builtin_ctor_queue; + else + queue = calloc(cnt, sizeof *queue); + + if (!queue) { + error("Error allocating constructor queue: %m\n"); + if (runtime) longjmp(*rtld_fail, 1); + return 0; + } + + /* Opposite ends of the allocated buffer serve as an output queue + * and a working stack. Setup initial stack with just the argument + * dso and initial queue empty... */ + stack = queue; + qpos = 0; + spos = cnt; + stack[--spos] = dso; + dso->next_dep = 0; + dso->mark = 1; + + /* Then perform pseudo-DFS sort, but ignoring circular deps. */ + while (sposnext_dep < p->ndeps_direct) { + if (p->deps[p->next_dep]->mark) { + p->next_dep++; + } else { + stack[--spos] = p; + p = p->deps[p->next_dep]; + p->next_dep = 0; + p->mark = 1; + } + } + queue[qpos++] = p; + } + queue[qpos] = 0; + for (i=0; imark = 0; + + return queue; +} + +static void do_init_fini(struct dso **queue) +{ + struct dso *p; + size_t dyn[DYN_CNT], i; + int self = __pthread_self()->tid; + + pthread_mutex_lock(&init_fini_lock); + for (i=0; (p=queue[i]); i++) { + while ((p->ctor_visitor && p->ctor_visitor!=self) || shutting_down) + pthread_cond_wait(&ctor_cond, &init_fini_lock); + if (p->ctor_visitor || p->constructed) + continue; + p->ctor_visitor = self; + decode_vec(p->dynv, dyn, DYN_CNT); if (dyn[0] & ((1<fini_next = fini_head; fini_head = p; } + + pthread_mutex_unlock(&init_fini_lock); + #ifndef NO_LEGACY_INITFINI if ((dyn[0] & (1<ctor_visitor = 0; + p->constructed = 1; + pthread_cond_broadcast(&ctor_cond); } - if (need_locking) pthread_mutex_unlock(&init_fini_lock); + pthread_mutex_unlock(&init_fini_lock); } void __libc_start_init(void) { - do_init_fini(tail); + do_init_fini(main_ctor_queue); + if (!__malloc_replaced && main_ctor_queue != builtin_ctor_queue) + free(main_ctor_queue); + main_ctor_queue = 0; } static void dl_debug_state(void) @@ -1356,7 +1535,8 @@ static void install_new_tls(void) { sigset_t set; pthread_t self = __pthread_self(), td; - uintptr_t (*newdtv)[tls_cnt+1] = (void *)tail->new_dtv; + struct dso *dtv_provider = container_of(tls_tail, struct dso, tls); + uintptr_t (*newdtv)[tls_cnt+1] = (void *)dtv_provider->new_dtv; struct dso *p; size_t i, j; size_t old_cnt = self->dtv[0]; @@ -1371,7 +1551,7 @@ static void install_new_tls(void) } /* Install new dtls into the enlarged, uninstalled dtv copies. */ for (p=head; ; p=p->next) { - if (!p->tls_id || self->dtv[p->tls_id]) continue; + if (p->tls_id <= old_cnt) continue; unsigned char *mem = p->new_tls; for (j=0; j