X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=6e79a77e67b90dc2ac3ce4891d38ae4aa8c6d484;hb=a735f53e6ab094bce9b992dd3d3127fdb4ffdcc2;hp=1cb3fb4c436da28e6285fa78f738995318a3e802;hpb=de45164effdddf500756e10e8c6f56b79301d82b;p=musl diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 1cb3fb4c..6e79a77e 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -1,6 +1,8 @@ #define _GNU_SOURCE #include #include +#include +#include #include #include #include @@ -17,26 +19,12 @@ #include #include "pthread_impl.h" #include "libc.h" +#include "dynlink.h" -static int errflag; -static char errbuf[128]; +static void error(const char *, ...); #ifdef SHARED -#if ULONG_MAX == 0xffffffff -typedef Elf32_Ehdr Ehdr; -typedef Elf32_Phdr Phdr; -typedef Elf32_Sym Sym; -#define R_TYPE(x) ((x)&255) -#define R_SYM(x) ((x)>>8) -#else -typedef Elf64_Ehdr Ehdr; -typedef Elf64_Phdr Phdr; -typedef Elf64_Sym Sym; -#define R_TYPE(x) ((x)&0xffffffff) -#define R_SYM(x) ((x)>>32) -#endif - #define MAXP2(a,b) (-(-(a)&-(b))) #define ALIGN(x,y) ((x)+(y)-1 & -(y)) @@ -48,6 +36,11 @@ struct debug { void *base; }; +struct td_index { + size_t args[2]; + struct td_index *next; +}; + struct dso { unsigned char *base; char *name; @@ -78,7 +71,8 @@ struct dso { size_t relro_start, relro_end; void **new_dtv; unsigned char *new_tls; - int new_dtv_idx, new_tls_idx; + volatile int new_dtv_idx, new_tls_idx; + struct td_index *td_index; struct dso *fini_next; char *shortname; char buf[]; @@ -89,14 +83,23 @@ struct symdef { struct dso *dso; }; -#include "reloc.h" - int __init_tp(void *); void __init_libc(char **, char *); const char *__libc_get_version(void); -static struct dso *head, *tail, *ldso, *fini_head; +static struct builtin_tls { + char c; + struct pthread pt; + void *space[16]; +} builtin_tls[1]; +#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt) + +#define ADDEND_LIMIT 4096 +static size_t *saved_addends, *apply_addends_to; + +static struct dso ldso; +static struct dso *head, *tail, *fini_head; static char *env_path, *sys_path; static unsigned long long gencnt; static int runtime; @@ -106,20 +109,28 @@ static int noload; static jmp_buf *rtld_fail; static pthread_rwlock_t lock; static struct debug debug; -static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t); +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 long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)]; struct debug *_dl_debug_addr = &debug; -#define AUX_CNT 38 -#define DYN_CNT 34 +static int dl_strcmp(const char *l, const char *r) +{ + for (; *l==*r && *l; l++, r++); + return *(unsigned char *)l - *(unsigned char *)r; +} +#define strcmp(l,r) dl_strcmp(l,r) + +/* Compute load address for a virtual address in a given dso. */ +#define laddr(p, v) (void *)((p)->base + (v)) static void decode_vec(size_t *v, size_t *a, size_t cnt) { - memset(a, 0, cnt*sizeof(size_t)); - for (; v[0]; v+=2) if (v[0]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 i = buckets[h1 % nbuckets]; if (!i) return 0; - hashval = buckets + nbuckets + (i - hashtab[1]); + uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]); for (h1 |= 1; ; i++) { - h2 = *hashval++; - if ((!dso->versym || dso->versym[i] >= 0) - && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name)) - return syms+i; + uint32_t h2 = *hashval++; + if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0) + && !strcmp(s, dso->strings + dso->syms[i].st_name)) + return dso->syms+i; if (h2 & 1) break; } return 0; } +static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask) +{ + const size_t *bloomwords = (const void *)(hashtab+4); + size_t f = bloomwords[fofs & (hashtab[2]-1)]; + if (!(f & fmask)) return 0; + + f >>= (h1 >> hashtab[3]) % (8 * sizeof f); + if (!(f & 1)) return 0; + + return gnu_lookup(h1, hashtab, dso, s); +} + #define OK_TYPES (1<next) { Sym *sym; if (!dso->global) continue; - if (dso->ghashtab) { - if (!gh) gh = gnu_hash(s); - sym = gnu_lookup(s, gh, dso); + if ((ght = dso->ghashtab)) { + if (!ghm) { + gh = gnu_hash(s); + int maskbits = 8 * sizeof ghm; + gho = gh / maskbits; + ghm = 1ul << gh % maskbits; + } + sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm); } else { if (!h) h = sysv_hash(s); sym = sysv_lookup(s, h, dso); } if (!sym) continue; if (!sym->st_shndx) - if (need_def || (sym->st_info&0xf) == STT_TLS) + if (need_def || (sym->st_info&0xf) == STT_TLS + || ARCH_SYM_REJECT_UND(sym)) continue; if (!sym->st_value) if ((sym->st_info&0xf) != STT_TLS) @@ -227,6 +256,9 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def) return def; } +__attribute__((__visibility__("hidden"))) +ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic(); + static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride) { unsigned char *base = dso->base; @@ -238,33 +270,136 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri int type; int sym_index; struct symdef def; + size_t *reloc_addr; + size_t sym_val; + size_t tls_val; + size_t addend; + int skip_relative = 0, reuse_addends = 0, save_slot = 0; + + if (dso == &ldso) { + /* Only ldso's REL table needs addend saving/reuse. */ + if (rel == apply_addends_to) + reuse_addends = 1; + skip_relative = 1; + } for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) { + if (skip_relative && IS_RELATIVE(rel[1])) continue; type = R_TYPE(rel[1]); + if (type == REL_NONE) continue; sym_index = R_SYM(rel[1]); + reloc_addr = laddr(dso, rel[0]); if (sym_index) { sym = syms + sym_index; name = strings + sym->st_name; - ctx = IS_COPY(type) ? head->next : head; - def = find_sym(ctx, name, IS_PLT(type)); + ctx = type==REL_COPY ? head->next : head; + def = find_sym(ctx, name, type==REL_PLT); 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", + error("Error relocating %s: %s: symbol not found", dso->name, name); if (runtime) longjmp(*rtld_fail, 1); - dprintf(2, "%s\n", errbuf); - ldso_fail = 1; continue; } } else { sym = 0; def.sym = 0; - def.dso = 0; + def.dso = dso; + } + + if (stride > 2) { + addend = rel[2]; + } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) { + addend = 0; + } else if (reuse_addends) { + /* Save original addend in stage 2 where the dso + * chain consists of just ldso; otherwise read back + * saved addend since the inline one was clobbered. */ + if (head==&ldso) + saved_addends[save_slot] = *reloc_addr; + addend = saved_addends[save_slot++]; + } else { + addend = *reloc_addr; + } + + sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0; + tls_val = def.sym ? def.sym->st_value : 0; + + switch(type) { + case REL_NONE: + break; + case REL_OFFSET: + addend -= (size_t)reloc_addr; + case REL_SYMBOLIC: + case REL_GOT: + case REL_PLT: + *reloc_addr = sym_val + addend; + break; + case REL_RELATIVE: + *reloc_addr = (size_t)base + addend; + break; + case REL_SYM_OR_REL: + if (sym) *reloc_addr = sym_val + addend; + else *reloc_addr = (size_t)base + addend; + break; + case REL_COPY: + memcpy(reloc_addr, (void *)sym_val, sym->st_size); + break; + case REL_OFFSET32: + *(uint32_t *)reloc_addr = sym_val + addend + - (size_t)reloc_addr; + break; + case REL_DTPMOD: + *reloc_addr = def.dso->tls_id; + break; + case REL_DTPOFF: + *reloc_addr = tls_val + addend - DTP_OFFSET; + break; +#ifdef TLS_ABOVE_TP + case REL_TPOFF: + *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend; + break; +#else + case REL_TPOFF: + *reloc_addr = tls_val - def.dso->tls_offset + addend; + break; + case REL_TPOFF_NEG: + *reloc_addr = def.dso->tls_offset - tls_val + addend; + break; +#endif + case REL_TLSDESC: + if (stride<3) addend = reloc_addr[1]; + if (runtime && def.dso->tls_id >= static_tls_cnt) { + struct td_index *new = malloc(sizeof *new); + if (!new) { + error( + "Error relocating %s: cannot allocate TLSDESC for %s", + dso->name, sym ? name : "(local)" ); + longjmp(*rtld_fail, 1); + } + new->next = dso->td_index; + dso->td_index = new; + new->args[0] = def.dso->tls_id; + new->args[1] = tls_val + addend; + reloc_addr[0] = (size_t)__tlsdesc_dynamic; + reloc_addr[1] = (size_t)new; + } else { + reloc_addr[0] = (size_t)__tlsdesc_static; +#ifdef TLS_ABOVE_TP + reloc_addr[1] = tls_val + def.dso->tls_offset + + TPOFF_K + addend; +#else + reloc_addr[1] = tls_val - def.dso->tls_offset + + addend; +#endif + } + break; + default: + error("Error relocating %s: unsupported relocation type %d", + dso->name, type); + if (runtime) longjmp(*rtld_fail, 1); + continue; } - do_single_reloc(dso, base, (void *)(base + rel[0]), type, - stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def, - def.sym?(size_t)(def.dso->base+def.sym->st_value):0); } } @@ -282,8 +417,8 @@ static void reclaim(struct dso *dso, size_t start, size_t end) 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 *)(dso->base + start); - z = (size_t *)(dso->base + end); + a = laddr(dso, start); + z = laddr(dso, end); a[-2] = 1; a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1; z[1] = 1; @@ -304,6 +439,28 @@ static void reclaim_gaps(struct dso *dso) } } +static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off) +{ + char *q = mmap(p, n, prot, flags, fd, off); + if (q != MAP_FAILED || errno != EINVAL) return q; + /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */ + if (flags & MAP_ANONYMOUS) { + memset(p, 0, n); + return p; + } + ssize_t r; + if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED; + for (q=p; n; q+=r, off+=r, n-=r) { + r = read(fd, q, n); + if (r < 0 && errno != EINTR) return MAP_FAILED; + if (!r) { + memset(q, 0, n); + break; + } + } + return p; +} + static void *map_library(int fd, struct dso *dso) { Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)]; @@ -405,19 +562,20 @@ static void *map_library(int fd, struct dso *dso) prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) | ((ph->p_flags&PF_X) ? PROT_EXEC : 0)); - if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED) + if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED) goto error; if (ph->p_memsz > ph->p_filesz) { size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz; size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE; memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1); - if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED) + if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED) goto error; } } for (i=0; ((size_t *)(base+dyn))[i]; i+=2) if (((size_t *)(base+dyn))[i]==DT_TEXTREL) { - if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0) + if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) + && errno != ENOSYS) goto error; break; } @@ -445,9 +603,20 @@ static int path_open(const char *name, const char *s, char *buf, size_t buf_size s += strspn(s, ":\n"); l = strcspn(s, ":\n"); if (l-1 >= INT_MAX) return -1; - if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size) - continue; - if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd; + if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) { + if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd; + switch (errno) { + case ENOENT: + case ENOTDIR: + case EACCES: + case ENAMETOOLONG: + break; + default: + /* Any negative value but -1 will inhibit + * futher path search. */ + return -2; + } + } s += l; } } @@ -457,8 +626,7 @@ 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 (p->rpath || !p->rpath_orig) return 0; if (!strchr(p->rpath_orig, '$')) { p->rpath = p->rpath_orig; return 0; @@ -467,11 +635,11 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) s = p->rpath_orig; while ((t=strchr(s, '$'))) { if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9)) - return -1; + return 0; s = t+1; n++; } - if (n > SSIZE_MAX/PATH_MAX) return -1; + if (n > SSIZE_MAX/PATH_MAX) return 0; if (p->kernel_mapped) { /* $ORIGIN searches cannot be performed for the main program @@ -481,10 +649,18 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) * since the library's pathname came from a trusted source * (either system paths or a call to dlopen). */ if (libc.secure) - return -1; + return 0; l = readlink("/proc/self/exe", buf, buf_size); - if (l >= buf_size) + if (l == -1) switch (errno) { + case ENOENT: + case ENOTDIR: + case EACCES: + break; + default: return -1; + } + if (l >= buf_size) + return 0; buf[l] = 0; origin = buf; } else { @@ -512,18 +688,20 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) static void decode_dyn(struct dso *p) { - size_t dyn[DYN_CNT] = {0}; + size_t dyn[DYN_CNT]; decode_vec(p->dynv, dyn, DYN_CNT); - p->syms = (void *)(p->base + dyn[DT_SYMTAB]); - p->strings = (void *)(p->base + dyn[DT_STRTAB]); + p->syms = laddr(p, dyn[DT_SYMTAB]); + p->strings = laddr(p, dyn[DT_STRTAB]); if (dyn[0]&(1<hashtab = (void *)(p->base + dyn[DT_HASH]); + p->hashtab = laddr(p, dyn[DT_HASH]); if (dyn[0]&(1<rpath_orig = (void *)(p->strings + dyn[DT_RPATH]); + if (dyn[0]&(1<rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]); if (search_vec(p->dynv, dyn, DT_GNU_HASH)) - p->ghashtab = (void *)(p->base + *dyn); + p->ghashtab = laddr(p, *dyn); if (search_vec(p->dynv, dyn, DT_VERSYM)) - p->versym = (void *)(p->base + *dyn); + p->versym = laddr(p, *dyn); } static struct dso *load_library(const char *name, struct dso *needed_by) @@ -538,6 +716,11 @@ static struct dso *load_library(const char *name, struct dso *needed_by) int n_th = 0; int is_self = 0; + if (!*name) { + errno = EINVAL; + return 0; + } + /* Catch and block attempts to reload the implementation itself */ if (name[0]=='l' && name[1]=='i' && name[2]=='b') { static const char *rp, reserved[] = @@ -555,22 +738,22 @@ static struct dso *load_library(const char *name, struct dso *needed_by) if (!(reported & mask)) { reported |= mask; dprintf(1, "\t%s => %s (%p)\n", - name, ldso->name, - ldso->base); + name, ldso.name, + ldso.base); } } is_self = 1; } } } - if (!strcmp(name, ldso->name)) is_self = 1; + if (!strcmp(name, ldso.name)) is_self = 1; if (is_self) { - if (!ldso->prev) { - tail->next = ldso; - ldso->prev = tail; - tail = ldso->next ? ldso->next : ldso; + if (!ldso.prev) { + tail->next = &ldso; + ldso.prev = tail; + tail = ldso.next ? ldso.next : &ldso; } - return ldso; + return &ldso; } if (strchr(name, '/')) { pathname = name; @@ -586,20 +769,23 @@ static struct dso *load_library(const char *name, struct dso *needed_by) if (strlen(name) > NAME_MAX) return 0; fd = -1; if (env_path) fd = path_open(name, env_path, buf, sizeof buf); - for (p=needed_by; fd < 0 && p; p=p->needed_by) - if (!fixup_rpath(p, buf, sizeof buf)) + for (p=needed_by; fd == -1 && p; p=p->needed_by) { + if (fixup_rpath(p, buf, sizeof buf) < 0) + fd = -2; /* Inhibit further search. */ + if (p->rpath) fd = path_open(name, p->rpath, buf, sizeof buf); - if (fd < 0) { + } + if (fd == -1) { if (!sys_path) { char *prefix = 0; size_t prefix_len; - if (ldso->name[0]=='/') { + if (ldso.name[0]=='/') { char *s, *t, *z; - for (s=t=z=ldso->name; *s; s++) + for (s=t=z=ldso.name; *s; s++) if (*s=='/') z=t, t=s; - prefix_len = z-ldso->name; + prefix_len = z-ldso.name; if (prefix_len < PATH_MAX) - prefix = ldso->name; + prefix = ldso.name; } if (!prefix) { prefix = ""; @@ -676,12 +862,6 @@ 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 && !libc.has_thread_pointer) { - munmap(map, p->map_len); - free(p); - errno = ENOSYS; - return 0; - } p->tls_id = ++tls_cnt; tls_align = MAXP2(tls_align, p->tls_align); #ifdef TLS_ABOVE_TP @@ -717,12 +897,9 @@ static void load_deps(struct dso *p) if (p->dynv[i] != DT_NEEDED) continue; 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)", + error("Error loading shared library %s: %m (needed by %s)", p->strings + p->dynv[i+1], p->name); if (runtime) longjmp(*rtld_fail, 1); - dprintf(2, "%s\n", errbuf); - ldso_fail = 1; continue; } if (runtime) { @@ -741,8 +918,8 @@ static void load_preload(char *s) int tmp; char *z; for (z=s; *z; s=z) { - for ( ; *s && isspace(*s); s++); - for (z=s; *z && !isspace(*z); z++); + for ( ; *s && (isspace(*s) || *s==':'); s++); + for (z=s; *z && !isspace(*z) && *z!=':'; z++); tmp = *z; *z = 0; load_library(s, 0); @@ -755,28 +932,45 @@ static void make_global(struct dso *p) for (; p; p=p->next) p->global = 1; } +static void do_mips_relocs(struct dso *p, size_t *got) +{ + size_t i, j, rel[2]; + unsigned char *base = p->base; + i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO); + if (p==&ldso) { + got += i; + } else { + while (i--) *got++ += (size_t)base; + } + j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM); + i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO); + Sym *sym = p->syms + j; + rel[0] = (unsigned char *)got - base; + for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) { + rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT; + do_relocs(p, rel, sizeof rel, 2); + } +} + static void reloc_all(struct dso *p) { - size_t dyn[DYN_CNT] = {0}; + size_t dyn[DYN_CNT]; for (; p; p=p->next) { if (p->relocated) continue; decode_vec(p->dynv, dyn, DYN_CNT); -#ifdef NEED_ARCH_RELOCS - do_arch_relocs(p, head); -#endif + if (NEED_MIPS_GOT_RELOCS) + do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT])); 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); - 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", + if (head != &ldso && p->relro_start != p->relro_end && + mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) + && errno != ENOSYS) { + error("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; @@ -789,7 +983,7 @@ static void kernel_mapped_dso(struct dso *p) 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); + p->dynv = laddr(p, 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; @@ -810,25 +1004,25 @@ static void kernel_mapped_dso(struct dso *p) static void do_fini() { struct dso *p; - size_t dyn[DYN_CNT] = {0}; + size_t dyn[DYN_CNT]; for (p=fini_head; p; p=p->fini_next) { if (!p->constructed) continue; decode_vec(p->dynv, dyn, DYN_CNT); if (dyn[0] & (1<base + dyn[DT_FINI_ARRAY])+n; + size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n; while (n--) ((void (*)(void))*--fn)(); } #ifndef NO_LEGACY_INITFINI if ((dyn[0] & (1<base + dyn[DT_FINI]))(); + ((void (*)(void))laddr(p, dyn[DT_FINI]))(); #endif } } static void do_init_fini(struct dso *p) { - size_t dyn[DYN_CNT] = {0}; + size_t dyn[DYN_CNT]; int need_locking = libc.threads_minus_1; /* Allow recursive calls that arise when a library calls * dlopen from one of its constructors, but block any @@ -844,11 +1038,11 @@ static void do_init_fini(struct dso *p) } #ifndef NO_LEGACY_INITFINI if ((dyn[0] & (1<base + dyn[DT_INIT]))(); + ((void (*)(void))laddr(p, dyn[DT_INIT]))(); #endif if (dyn[0] & (1<base + dyn[DT_INIT_ARRAY]); + size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]); while (n--) ((void (*)(void))*fn++)(); } if (!need_locking && libc.threads_minus_1) { @@ -859,10 +1053,12 @@ static void do_init_fini(struct dso *p) if (need_locking) pthread_mutex_unlock(&init_fini_lock); } -void _dl_debug_state(void) +static void dl_debug_state(void) { } +weak_alias(dl_debug_state, _dl_debug_state); + void __reset_tls() { pthread_t self = __pthread_self(); @@ -880,17 +1076,11 @@ void *__copy_tls(unsigned char *mem) { pthread_t td; struct dso *p; - - void **dtv = (void *)mem; - dtv[0] = (void *)tls_cnt; - if (!tls_cnt) { - td = (void *)(dtv+1); - td->dtv = dtv; - return td; - } + void **dtv; #ifdef TLS_ABOVE_TP - mem += sizeof(void *) * (tls_cnt+1); + dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1); + mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1); td = (pthread_t)mem; mem += sizeof(struct pthread); @@ -901,6 +1091,8 @@ void *__copy_tls(unsigned char *mem) memcpy(dtv[p->tls_id], p->tls_image, p->tls_len); } #else + dtv = (void **)mem; + mem += libc.tls_size - sizeof(struct pthread); mem -= (uintptr_t)mem & (tls_align-1); td = (pthread_t)mem; @@ -911,22 +1103,22 @@ void *__copy_tls(unsigned char *mem) memcpy(dtv[p->tls_id], p->tls_image, p->tls_len); } #endif - td->dtv = dtv; + dtv[0] = (void *)tls_cnt; + td->dtv = td->dtv_copy = dtv; return td; } -void *__tls_get_addr(size_t *v) +__attribute__((__visibility__("hidden"))) +void *__tls_get_new(size_t *v) { pthread_t self = __pthread_self(); - if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) - return (char *)self->dtv[v[0]]+v[1]; /* Block signals to make accessing new TLS async-signal-safe */ sigset_t set; - pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set); - if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) { - pthread_sigmask(SIG_SETMASK, &set, 0); - return (char *)self->dtv[v[0]]+v[1]; + __block_all_sigs(&set); + if (v[0]<=(size_t)self->dtv[0]) { + __restore_sigs(&set); + return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET; } /* This is safe without any locks held because, if the caller @@ -943,17 +1135,23 @@ void *__tls_get_addr(size_t *v) memcpy(newdtv, self->dtv, ((size_t)self->dtv[0]+1) * sizeof(void *)); newdtv[0] = (void *)v[0]; - self->dtv = newdtv; + self->dtv = self->dtv_copy = newdtv; } - /* Get new TLS memory from new DSO */ - unsigned char *mem = p->new_tls + - (p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1); - mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1); - self->dtv[v[0]] = mem; - memcpy(mem, p->tls_image, p->tls_len); - pthread_sigmask(SIG_SETMASK, &set, 0); - return mem + v[1]; + /* Get new TLS memory from all new DSOs up to the requested one */ + unsigned char *mem; + for (p=head; ; p=p->next) { + if (!p->tls_id || self->dtv[p->tls_id]) continue; + mem = p->new_tls + (p->tls_size + p->tls_align) + * a_fetch_add(&p->new_tls_idx,1); + mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) + & (p->tls_align-1); + self->dtv[p->tls_id] = mem; + memcpy(mem, p->tls_image, p->tls_len); + if (p->tls_id == v[0]) break; + } + __restore_sigs(&set); + return mem + v[1] + DTP_OFFSET; } static void update_tls_size() @@ -966,95 +1164,135 @@ static void update_tls_size() tls_align); } -void *__dynlink(int argc, char **argv) +/* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the + * following stage 2 and stage 3 functions via primitive symbolic lookup + * since it does not have access to their addresses to begin with. */ + +/* Stage 2 of the dynamic linker is called after relative relocations + * have been processed. It can make function calls to static functions + * and access string literals and static data, but cannot use extern + * symbols. Its job is to perform symbolic relocations on the dynamic + * linker itself, but some of the relocations performed may need to be + * replaced later due to copy relocations in the main program. */ + +void __dls2(unsigned char *base, size_t *sp) { - size_t aux[AUX_CNT] = {0}; + Ehdr *ehdr = (void *)base; + ldso.base = base; + ldso.name = ldso.shortname = "libc.so"; + ldso.global = 1; + ldso.phnum = ehdr->e_phnum; + ldso.phdr = (void *)(base + ehdr->e_phoff); + ldso.phentsize = ehdr->e_phentsize; + kernel_mapped_dso(&ldso); + decode_dyn(&ldso); + + /* Prepare storage for to save clobbered REL addends so they + * can be reused in stage 3. There should be very few. If + * something goes wrong and there are a huge number, abort + * instead of risking stack overflow. */ + size_t dyn[DYN_CNT]; + decode_vec(ldso.dynv, dyn, DYN_CNT); + size_t *rel = (void *)(base+dyn[DT_REL]); + size_t rel_size = dyn[DT_RELSZ]; + size_t symbolic_rel_cnt = 0; + apply_addends_to = rel; + for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t)) + if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++; + if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash(); + size_t addends[symbolic_rel_cnt+1]; + saved_addends = addends; + + head = &ldso; + reloc_all(&ldso); + + ldso.relocated = 0; + + /* Call dynamic linker stage-3, __dls3, looking it up + * symbolically as a barrier against moving the address + * load across the above relocation processing. */ + struct symdef dls3_def = find_sym(&ldso, "__dls3", 0); + ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp); +} + +/* Stage 3 of the dynamic linker is called with the dynamic linker/libc + * fully functional. Its job is to load (if not already loaded) and + * process dependencies and relocations for the main application and + * transfer control to its entry point. */ + +_Noreturn void __dls3(size_t *sp) +{ + static struct dso app, vdso; + size_t aux[AUX_CNT], *auxv; size_t i; - Phdr *phdr; - Ehdr *ehdr; - static struct dso builtin_dsos[3]; - struct dso *const app = builtin_dsos+0; - struct dso *const lib = builtin_dsos+1; - struct dso *const vdso = builtin_dsos+2; char *env_preload=0; size_t vdso_base; - size_t *auxv; + int argc = *sp; + char **argv = (void *)(sp+1); + char **argv_orig = argv; char **envp = argv+argc+1; - void *initial_tls; - - /* Find aux vector just past environ[] */ - for (i=argc+1; argv[i]; i++) - if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16)) - env_path = argv[i]+16; - else if (!memcmp(argv[i], "LD_PRELOAD=", 11)) - env_preload = argv[i]+11; - auxv = (void *)(argv+i+1); + /* Find aux vector just past environ[] and use it to initialize + * global data that may be needed before we can make syscalls. */ + __environ = envp; + for (i=argc+1; argv[i]; i++); + libc.auxv = auxv = (void *)(argv+i+1); decode_vec(auxv, aux, AUX_CNT); - - /* Only trust user/env if kernel says we're not suid/sgid */ - if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID] - || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) { - env_path = 0; - env_preload = 0; - libc.secure = 1; - } + __hwcap = aux[AT_HWCAP]; libc.page_size = aux[AT_PAGESZ]; + libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID] + || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]); + + /* Setup early thread pointer in builtin_tls for ldso/libc itself to + * use during dynamic linking. If possible it will also serve as the + * thread pointer at runtime. */ + libc.tls_size = sizeof builtin_tls; + if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) { + a_crash(); + } - /* 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 - * the start of the page containing the PHDRs; I don't know any - * better approach... */ - if (!aux[AT_BASE]) { - aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE; - aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0; + /* Only trust user/env if kernel says we're not suid/sgid */ + if (!libc.secure) { + env_path = getenv("LD_LIBRARY_PATH"); + env_preload = getenv("LD_PRELOAD"); } - /* The dynamic linker load address is passed by the kernel - * in the AUX vector, so this is easy. */ - lib->base = (void *)aux[AT_BASE]; - lib->name = lib->shortname = "libc.so"; - lib->global = 1; - ehdr = (void *)lib->base; - lib->phnum = ehdr->e_phnum; - lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff); - lib->phentsize = ehdr->e_phentsize; - kernel_mapped_dso(lib); - decode_dyn(lib); - - if (aux[AT_PHDR]) { + /* If the main program was already loaded by the kernel, + * AT_PHDR will point to some location other than the dynamic + * linker's program headers. */ + if (aux[AT_PHDR] != (size_t)ldso.phdr) { size_t interp_off = 0; size_t tls_image = 0; /* 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]; + Phdr *phdr = app.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); + app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr); else if (phdr->p_type == PT_INTERP) interp_off = (size_t)phdr->p_vaddr; else if (phdr->p_type == PT_TLS) { tls_image = phdr->p_vaddr; - app->tls_len = phdr->p_filesz; - app->tls_size = phdr->p_memsz; - app->tls_align = phdr->p_align; + app.tls_len = phdr->p_filesz; + app.tls_size = phdr->p_memsz; + app.tls_align = phdr->p_align; } } - if (app->tls_size) app->tls_image = (char *)app->base + tls_image; - if (interp_off) lib->name = (char *)app->base + interp_off; + if (app.tls_size) app.tls_image = laddr(&app, tls_image); + if (interp_off) ldso.name = laddr(&app, interp_off); if ((aux[0] & (1UL<name = (char *)aux[AT_EXECFN]; + app.name = (char *)aux[AT_EXECFN]; else - app->name = argv[0]; - kernel_mapped_dso(app); + app.name = argv[0]; + kernel_mapped_dso(&app); } else { int fd; char *ldname = argv[0]; size_t l = strlen(ldname); if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1; - *argv++ = (void *)-1; + argv++; while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') { char *opt = argv[0]+2; *argv++ = (void *)-1; @@ -1073,8 +1311,8 @@ void *__dynlink(int argc, char **argv) } else { argv[0] = 0; } - argv[-1] = (void *)-1; } + argv[-1] = (void *)(argc - (argv-argv_orig)); if (!argv[0]) { dprintf(2, "musl libc\n" "Version %s\n" @@ -1090,126 +1328,124 @@ void *__dynlink(int argc, char **argv) _exit(1); } runtime = 1; - ehdr = (void *)map_library(fd, app); + Ehdr *ehdr = (void *)map_library(fd, &app); if (!ehdr) { dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]); _exit(1); } runtime = 0; close(fd); - lib->name = ldname; - app->name = argv[0]; - aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry; + ldso.name = ldname; + app.name = argv[0]; + aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry); /* Find the name that would have been used for the dynamic * linker had ldd not taken its place. */ if (ldd_mode) { - for (i=0; iphnum; i++) { - if (app->phdr[i].p_type == PT_INTERP) - lib->name = (void *)(app->base - + app->phdr[i].p_vaddr); + for (i=0; iname, lib->base); + dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base); } } - if (app->tls_size) { - app->tls_id = tls_cnt = 1; + if (app.tls_size) { + app.tls_id = tls_cnt = 1; #ifdef TLS_ABOVE_TP - app->tls_offset = 0; - tls_offset = app->tls_size - + ( -((uintptr_t)app->tls_image + app->tls_size) - & (app->tls_align-1) ); + app.tls_offset = 0; + tls_offset = app.tls_size + + ( -((uintptr_t)app.tls_image + app.tls_size) + & (app.tls_align-1) ); #else - tls_offset = app->tls_offset = app->tls_size - + ( -((uintptr_t)app->tls_image + app->tls_size) - & (app->tls_align-1) ); + tls_offset = app.tls_offset = app.tls_size + + ( -((uintptr_t)app.tls_image + app.tls_size) + & (app.tls_align-1) ); #endif - tls_align = MAXP2(tls_align, app->tls_align); + tls_align = MAXP2(tls_align, app.tls_align); } - app->global = 1; - decode_dyn(app); + app.global = 1; + decode_dyn(&app); /* Attach to vdso, if provided by the kernel */ if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) { - ehdr = (void *)vdso_base; - vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff); - vdso->phnum = ehdr->e_phnum; - vdso->phentsize = ehdr->e_phentsize; + Ehdr *ehdr = (void *)vdso_base; + Phdr *phdr = vdso.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); + vdso.dynv = (void *)(vdso_base + phdr->p_offset); if (phdr->p_type == PT_LOAD) - vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset); + vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset); } - vdso->name = ""; - vdso->shortname = "linux-gate.so.1"; - vdso->global = 1; - decode_dyn(vdso); - vdso->prev = lib; - lib->next = vdso; + vdso.name = ""; + vdso.shortname = "linux-gate.so.1"; + vdso.global = 1; + vdso.relocated = 1; + decode_dyn(&vdso); + vdso.prev = &ldso; + ldso.next = &vdso; } - /* Initial dso chain consists only of the app. We temporarily - * append the dynamic linker/libc so we can relocate it, then - * restore the initial chain in preparation for loading third - * party libraries (preload/needed). */ - head = tail = app; - ldso = lib; - app->next = lib; - reloc_all(lib); - app->next = 0; - - /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */ + /* Initial dso chain consists only of the app. */ + head = tail = &app; /* Donate unused parts of app and library mapping to malloc */ - reclaim_gaps(app); - reclaim_gaps(lib); + reclaim_gaps(&app); + reclaim_gaps(&ldso); /* Load preload/needed libraries, add their symbols to the global - * namespace, and perform all remaining relocations. The main - * program must be relocated LAST since it may contain copy - * relocations which depend on libraries' relocations. */ + * namespace, and perform all remaining relocations. */ if (env_preload) load_preload(env_preload); - load_deps(app); - make_global(app); + 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; + 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); + /* The main program must be relocated LAST since it may contin + * copy relocations which depend on libraries' relocations. */ + reloc_all(app.next); + reloc_all(&app); update_tls_size(); - if (libc.tls_size > sizeof builtin_tls) { - initial_tls = calloc(libc.tls_size, 1); + if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) { + void *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); } + if (__init_tp(__copy_tls(initial_tls)) < 0) { + a_crash(); + } } 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); + size_t tmp_tls_size = libc.tls_size; + pthread_t self = __pthread_self(); + /* Temporarily set the tls size to the full size of + * builtin_tls so that __copy_tls will use the same layout + * as it did for before. Then check, just to be safe. */ + libc.tls_size = sizeof builtin_tls; + if (__copy_tls((void*)builtin_tls) != self) a_crash(); + libc.tls_size = tmp_tls_size; } + static_tls_cnt = tls_cnt; if (ldso_fail) _exit(127); if (ldd_mode) _exit(0); /* Switch to runtime mode: any further failures in the dynamic * linker are a reportable failure rather than a fatal startup - * error. If the dynamic loader (dlopen) will not be used, free - * all memory used by the dynamic linker. */ + * error. */ runtime = 1; debug.ver = 1; - debug.bp = _dl_debug_state; + debug.bp = dl_debug_state; debug.head = head; - debug.base = lib->base; + debug.base = ldso.base; debug.state = 0; _dl_debug_state(); @@ -1218,7 +1454,8 @@ void *__dynlink(int argc, char **argv) errno = 0; do_init_fini(tail); - return (void *)aux[AT_ENTRY]; + CRTJMP((void *)aux[AT_ENTRY], argv-1); + for(;;); } void *dlopen(const char *file, int mode) @@ -1251,6 +1488,13 @@ void *dlopen(const char *file, int mode) for (p=orig_tail->next; p; p=next) { next = p->next; munmap(p->map, p->map_len); + while (p->td_index) { + void *tmp = p->td_index->next; + free(p->td_index); + p->td_index = tmp; + } + if (p->rpath != p->rpath_orig) + free(p->rpath); free(p->deps); free(p); } @@ -1260,16 +1504,14 @@ void *dlopen(const char *file, int mode) tail = orig_tail; tail->next = 0; p = 0; - errflag = 1; goto end; } else p = load_library(file, head); if (!p) { - snprintf(errbuf, sizeof errbuf, noload ? + error(noload ? "Library %s is not already loaded" : "Error loading shared library %s: %m", file); - errflag = 1; goto end; } @@ -1309,15 +1551,16 @@ static int invalid_dso_handle(void *h) { struct dso *p; for (p=head; p; p=p->next) if (h==p) return 0; - snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h); - errflag = 1; + error("Invalid library handle %p", (void *)h); return 1; } +void *__tls_get_addr(size_t *); + static void *do_dlsym(struct dso *p, const char *s, void *ra) { size_t i; - uint32_t h = 0, gh = 0; + uint32_t h = 0, gh = 0, *ght; Sym *sym; if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) { if (p == RTLD_DEFAULT) { @@ -1331,13 +1574,13 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra) if (!def.sym) goto failed; if ((def.sym->st_info&0xf) == STT_TLS) return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value}); - return def.dso->base + def.sym->st_value; + return laddr(def.dso, def.sym->st_value); } - if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p)) + if (invalid_dso_handle(p)) return 0; - if (p->ghashtab) { + if ((ght = p->ghashtab)) { gh = gnu_hash(s); - sym = gnu_lookup(s, gh, p); + sym = gnu_lookup(gh, ght, p, s); } else { h = sysv_hash(s); sym = sysv_lookup(s, h, p); @@ -1345,11 +1588,11 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra) if (sym && (sym->st_info&0xf) == STT_TLS) return __tls_get_addr((size_t []){p->tls_id, sym->st_value}); if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) - return p->base + sym->st_value; + return laddr(p, sym->st_value); if (p->deps) for (i=0; p->deps[i]; i++) { - if (p->deps[i]->ghashtab) { + if ((ght = p->deps[i]->ghashtab)) { if (!gh) gh = gnu_hash(s); - sym = gnu_lookup(s, gh, p->deps[i]); + sym = gnu_lookup(gh, ght, p->deps[i], s); } else { if (!h) h = sysv_hash(s); sym = sysv_lookup(s, h, p->deps[i]); @@ -1357,11 +1600,10 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra) if (sym && (sym->st_info&0xf) == STT_TLS) return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value}); if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) - return p->deps[i]->base + sym->st_value; + return laddr(p->deps[i], sym->st_value); } failed: - errflag = 1; - snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s); + error("Symbol not found: %s", s); return 0; } @@ -1406,7 +1648,7 @@ int __dladdr(const void *addr, Dl_info *info) if (sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES) && (1<<(sym->st_info>>4) & OK_BINDS)) { - void *symaddr = p->base + sym->st_value; + void *symaddr = laddr(p, sym->st_value); if (symaddr > addr || symaddr < best) continue; best = symaddr; @@ -1426,6 +1668,7 @@ int __dladdr(const void *addr, Dl_info *info) return 1; } +__attribute__((__visibility__("hidden"))) void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) { void *res; @@ -1463,16 +1706,17 @@ int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void #else static int invalid_dso_handle(void *h) { - snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h); - errflag = 1; + error("Invalid library handle %p", (void *)h); return 1; } void *dlopen(const char *file, int mode) { + error("Dynamic loading not supported"); return 0; } void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) { + error("Symbol not found: %s", s); return 0; } int __dladdr (const void *addr, Dl_info *info) @@ -1485,8 +1729,7 @@ int __dlinfo(void *dso, int req, void *res) { if (invalid_dso_handle(dso)) return -1; if (req != RTLD_DI_LINKMAP) { - snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req); - errflag = 1; + error("Unsupported request %d", req); return -1; } *(struct link_map **)res = dso; @@ -1495,12 +1738,54 @@ int __dlinfo(void *dso, int req, void *res) char *dlerror() { - if (!errflag) return 0; - errflag = 0; - return errbuf; + pthread_t self = __pthread_self(); + if (!self->dlerror_flag) return 0; + self->dlerror_flag = 0; + char *s = self->dlerror_buf; + if (s == (void *)-1) + return "Dynamic linker failed to allocate memory for error message"; + else + return s; } int dlclose(void *p) { return invalid_dso_handle(p); } + +void __dl_thread_cleanup(void) +{ + pthread_t self = __pthread_self(); + if (self->dlerror_buf != (void *)-1) + free(self->dlerror_buf); +} + +static void error(const char *fmt, ...) +{ + va_list ap; + va_start(ap, fmt); +#ifdef SHARED + if (!runtime) { + vdprintf(2, fmt, ap); + dprintf(2, "\n"); + ldso_fail = 1; + va_end(ap); + return; + } +#endif + pthread_t self = __pthread_self(); + if (self->dlerror_buf != (void *)-1) + free(self->dlerror_buf); + size_t len = vsnprintf(0, 0, fmt, ap); + va_end(ap); + char *buf = malloc(len+1); + if (buf) { + va_start(ap, fmt); + vsnprintf(buf, len+1, fmt, ap); + va_end(ap); + } else { + buf = (void *)-1; + } + self->dlerror_buf = buf; + self->dlerror_flag = 1; +}