X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=de0f2ac876ab763ff236f5a0d2ef75311fd7549c;hb=e13a2b8953efabd38edfb7637fda08638454c001;hp=573af75073f293d3fa751ce778e8ebe8760a0e35;hpb=d2c42ed25f0488c40f61479ac7feb729d98e1d38;p=musl diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 573af750..de0f2ac8 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 @@ -77,6 +74,7 @@ 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; @@ -93,9 +91,11 @@ 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; @@ -109,6 +109,7 @@ 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; @@ -254,7 +255,8 @@ 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 +282,29 @@ 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, Phdr *ph, size_t phent, size_t phcnt) { for (; phcnt--; ph=(void *)((char *)ph+phent)) { 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); } } @@ -345,11 +349,14 @@ static void *map_library(int fd, struct dso *dso) for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) { 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) { @@ -418,12 +425,12 @@ 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, ph0, eh->e_phentsize, eh->e_phnum); free(allocated_buf); return map; noexec: @@ -614,6 +621,8 @@ 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"; @@ -671,9 +680,10 @@ 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; @@ -762,6 +772,17 @@ 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", + p->name); + if (runtime) longjmp(*rtld_fail, 1); + dprintf(2, "%s\n", errbuf); + ldso_fail = 1; + } + p->relocated = 1; } } @@ -778,6 +799,10 @@ 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)) { + 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; @@ -864,10 +889,13 @@ 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); @@ -960,6 +988,7 @@ 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++) @@ -978,6 +1007,7 @@ 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 @@ -1040,8 +1070,11 @@ 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); } @@ -1121,9 +1154,9 @@ 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]); + reclaim_gaps(app, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]); ehdr = (void *)lib->base; - reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff), + reclaim_gaps(lib, (void *)(lib->base+ehdr->e_phoff), ehdr->e_phentsize, ehdr->e_phnum); /* Load preload/needed libraries, add their symbols to the global @@ -1134,19 +1167,29 @@ 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); @@ -1158,11 +1201,6 @@ 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; @@ -1220,7 +1258,7 @@ 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 ? @@ -1326,7 +1364,7 @@ failed: return 0; } -int __dladdr(void *addr, Dl_info *info) +int __dladdr(const void *addr, Dl_info *info) { struct dso *p; Sym *sym; @@ -1351,7 +1389,7 @@ 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]; } @@ -1436,7 +1474,7 @@ 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; }