X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=cab30089e5d1cc0ceeb58f50d1f81805f1ad11b7;hb=bd275378d35b3535bc8b8321780b00e486c36d96;hp=93a4b44c1165035db3e2852e8db682cd9b664643;hpb=8b28aa9c94e7c6179d70fe73afcd3fff29809d61;p=musl diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 93a4b44c..cab30089 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -1,41 +1,32 @@ #define _GNU_SOURCE #include #include +#include +#include #include #include #include #include #include #include -#include #include #include #include -#include -#include +#include #include #include #include #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)) struct debug { int ver; @@ -45,16 +36,29 @@ struct debug { void *base; }; +struct td_index { + size_t args[2]; + struct td_index *next; +}; + struct dso { +#if DL_FDPIC + struct fdpic_loadmap *loadmap; +#else unsigned char *base; +#endif char *name; size_t *dynv; struct dso *next, *prev; + Phdr *phdr; + int phnum; + size_t phentsize; int refcnt; Sym *syms; uint32_t *hashtab; uint32_t *ghashtab; + int16_t *versym; char *strings; unsigned char *map; size_t map_len; @@ -63,37 +67,99 @@ 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; + size_t relro_start, relro_end; + void **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; +#if DL_FDPIC + unsigned char *base; +#else + struct fdpic_loadmap *loadmap; +#endif + struct funcdesc { + void *addr; + size_t *got; + } *funcdescs; + size_t *got; char buf[]; }; -#include "reloc.h" +struct symdef { + Sym *sym; + struct dso *dso; +}; + +int __init_tp(void *); +void __init_libc(char **, char *); -void __init_ssp(size_t *); +const char *__libc_get_version(void); -static struct dso *head, *tail, *libc; -static char *env_path, *sys_path, *r_path; -static int rtld_used; -static int ssp_used; +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; static int ldd_mode; static int ldso_fail; -static jmp_buf rtld_fail; +static int noload; +static jmp_buf *rtld_fail; static pthread_rwlock_t lock; static struct debug debug; -static size_t *auxv; +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 struct fdpic_loadmap *app_loadmap; +static struct fdpic_dummy_loadmap app_dummy_loadmap; struct debug *_dl_debug_addr = &debug; -#define AUX_CNT 24 -#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. */ +#if DL_FDPIC +static void *laddr(const struct dso *p, size_t v) +{ + size_t j=0; + if (!p->loadmap) return p->base + v; + for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++); + return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr); +} +#define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \ + laddr(p, v), (p)->got }) +#else +#define laddr(p, v) (void *)((p)->base + (v)) +#define fpaddr(p, v) ((void (*)())laddr(p, v)) +#endif 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]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; } -static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso) +static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s) { - 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]; + 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]); + uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]); - for (h1 |= 1; ; sym++) { - h2 = *hashval++; - if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name)) - return sym; + for (h1 |= 1; ; 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; } -#define OK_TYPES (1<>= (h1 >> hashtab[3]) % (8 * sizeof f); + if (!(f & 1)) return 0; + + return gnu_lookup(h1, hashtab, dso, s); +} + +#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; - } + uint32_t h = 0, gh, gho, *ght; + size_t ghm = 0; + struct symdef def = {0}; for (; dso; dso=dso->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 && (!need_def || sym->st_shndx) && sym->st_value - && (1<<(sym->st_info&0xf) & OK_TYPES) - && (1<<(sym->st_info>>4) & OK_BINDS)) { - if (def && sym->st_info>>4 == STB_WEAK) continue; - def = dso->base + sym->st_value; - if (sym->st_info>>4 == STB_GLOBAL) break; - } + if (!sym) continue; + if (!sym->st_shndx) + 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) + continue; + if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue; + if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue; + + if (def.sym && sym->st_info>>4 == STB_WEAK) continue; + def.sym = sym; + def.dso = dso; + if (sym->st_info>>4 == STB_GLOBAL) break; } 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; @@ -212,35 +295,151 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri char *strings = dso->strings; Sym *sym; const char *name; - size_t sym_val, sym_size; - size_t *reloc_addr; void *ctx; 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)) { - reloc_addr = (void *)(base + rel[0]); + if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) 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; - sym_val = (size_t)find_sym(ctx, name, IS_PLT(type)); - if (!sym_val && sym->st_info>>4 != STB_WEAK) { - snprintf(errbuf, sizeof errbuf, - "Error relocating %s: %s: symbol not found", + ctx = type==REL_COPY ? head->next : head; + def = (sym->st_info&0xf) == STT_SECTION + ? (struct symdef){ .dso = dso, .sym = sym } + : find_sym(ctx, name, type==REL_PLT); + if (!def.sym && (sym->st_shndx != SHN_UNDEF + || sym->st_info>>4 != STB_WEAK)) { + 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; + if (runtime) longjmp(*rtld_fail, 1); continue; } - sym_size = sym->st_size; } else { - sym_val = sym_size = 0; + sym = 0; + def.sym = 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_FUNCDESC: + *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs + + (def.sym - def.dso->syms)) : 0; + break; + case REL_FUNCDESC_VAL: + if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val; + else *reloc_addr = sym_val; + reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0; + 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(reloc_addr, type, sym_val, sym_size, base, rel[2]); } } @@ -250,60 +449,127 @@ 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 = laddr(dso, start); + z = laddr(dso, 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) { - for (; phcnt--; ph=(void *)((char *)ph+phent)) { + Phdr *ph = dso->phdr; + size_t phcnt = dso->phnum; + + if (DL_FDPIC) return; // FIXME + for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) { 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); } } -static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dynp) +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 unmap_library(struct dso *dso) +{ + if (dso->loadmap) { + size_t i; + for (i=0; iloadmap->nsegs; i++) { + if (!dso->loadmap->segs[i].p_memsz) + continue; + munmap((void *)dso->loadmap->segs[i].addr, + dso->loadmap->segs[i].p_memsz); + } + free(dso->loadmap); + } else if (dso->map && dso->map_len) { + munmap(dso->map, dso->map_len); + } +} + +static void *map_library(int fd, struct dso *dso) { Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)]; + void *allocated_buf=0; size_t phsize; size_t addr_min=SIZE_MAX, addr_max=0, map_len; size_t this_min, this_max; + size_t nsegs = 0; off_t off_start; Ehdr *eh; - Phdr *ph; + Phdr *ph, *ph0; unsigned prot; - unsigned char *map, *base; - size_t dyn; + unsigned char *map=MAP_FAILED, *base; + size_t dyn=0; + size_t tls_image=0; size_t i; ssize_t l = read(fd, buf, sizeof buf); - if (le_type != ET_DYN && eh->e_type != ET_EXEC)) + goto noexec; phsize = eh->e_phentsize * eh->e_phnum; - if (phsize + sizeof *eh > l) return 0; - if (eh->e_phoff + phsize > l) { + if (phsize > sizeof buf - sizeof *eh) { + allocated_buf = malloc(phsize); + if (!allocated_buf) return 0; + l = pread(fd, allocated_buf, phsize, eh->e_phoff); + if (l < 0) goto error; + if (l != phsize) goto noexec; + ph = ph0 = allocated_buf; + } else if (eh->e_phoff + phsize > l) { l = pread(fd, buf+1, phsize, eh->e_phoff); - if (l != phsize) return 0; - eh->e_phoff = sizeof *eh; + if (l < 0) goto error; + if (l != phsize) goto noexec; + ph = ph0 = (void *)(buf + 1); + } else { + ph = ph0 = (void *)((char *)buf + eh->e_phoff); } - ph = (void *)((char *)buf + eh->e_phoff); for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) { - if (ph->p_type == PT_DYNAMIC) + if (ph->p_type == PT_DYNAMIC) { dyn = ph->p_vaddr; + } 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; + nsegs++; if (ph->p_vaddr < addr_min) { addr_min = ph->p_vaddr; off_start = ph->p_offset; @@ -315,7 +581,34 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy addr_max = ph->p_vaddr+ph->p_memsz; } } - if (!dyn) return 0; + if (!dyn) goto noexec; + if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) { + dso->loadmap = calloc(1, sizeof *dso->loadmap + + nsegs * sizeof *dso->loadmap->segs); + if (!dso->loadmap) goto error; + dso->loadmap->nsegs = nsegs; + for (ph=ph0, i=0; ie_phentsize)) { + if (ph->p_type != PT_LOAD) continue; + 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)); + map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1), + prot, (prot&PROT_WRITE) ? MAP_PRIVATE : MAP_SHARED, + fd, ph->p_offset & -PAGE_SIZE); + if (map == MAP_FAILED) { + unmap_library(dso); + goto error; + } + dso->loadmap->segs[i].addr = (size_t)map + + (ph->p_vaddr & PAGE_SIZE-1); + dso->loadmap->segs[i].p_vaddr = ph->p_vaddr; + dso->loadmap->segs[i].p_memsz = ph->p_memsz; + i++; + } + map = (void *)dso->loadmap->segs[0].addr; + map_len = 0; + goto done_mapping; + } addr_max += PAGE_SIZE-1; addr_max &= -PAGE_SIZE; addr_min &= -PAGE_SIZE; @@ -326,11 +619,29 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy * use the invalid part; we just need to reserve the right * amount of virtual address space to map over later. */ map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start); - if (map==MAP_FAILED) return 0; + if (map==MAP_FAILED) goto error; + dso->map = map; + dso->map_len = map_len; + /* If the loaded file is not relocatable and the requested address is + * not available, then the load operation must fail. */ + if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) { + errno = EBUSY; + goto error; + } base = map - addr_min; - ph = (void *)((char *)buf + eh->e_phoff); - for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) { + dso->phdr = 0; + dso->phnum = 0; + for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) { if (ph->p_type != PT_LOAD) continue; + /* Check if the programs headers are in this load segment, and + * if so, record the address for use by dl_iterate_phdr. */ + if (!dso->phdr && eh->e_phoff >= ph->p_offset + && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) { + dso->phdr = (void *)(base + ph->p_vaddr + + (eh->e_phoff-ph->p_offset)); + dso->phnum = eh->e_phnum; + dso->phentsize = eh->e_phentsize; + } /* Reuse the existing mapping for the lowest-address LOAD */ if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue; this_min = ph->p_vaddr & -PAGE_SIZE; @@ -339,69 +650,224 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy 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; } - if (!runtime) reclaim_gaps(base, (void *)((char *)buf + eh->e_phoff), - eh->e_phentsize, eh->e_phnum); - *lenp = map_len; - *basep = base; - *dynp = dyn; +done_mapping: + dso->base = base; + dso->dynv = laddr(dso, dyn); + if (dso->tls_size) dso->tls_image = laddr(dso, tls_image); + if (!runtime) reclaim_gaps(dso); + free(allocated_buf); return map; +noexec: + errno = ENOEXEC; error: - munmap(map, map_len); + if (map!=MAP_FAILED) unmap_library(dso); + free(allocated_buf); return 0; } -static int path_open(const char *name, const char *search, char *buf, size_t buf_size) +static int path_open(const char *name, const char *s, char *buf, size_t buf_size) { - const char *s=search, *z; - int l, fd; + size_t l; + int fd; for (;;) { - while (*s==':') s++; - if (!*s) return -1; - z = strchr(s, ':'); - l = z ? z-s : strlen(s); - snprintf(buf, buf_size, "%.*s/%s", l, s, name); - if ((fd = open(buf, O_RDONLY))>=0) return fd; + 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) { + 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; } } +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 || !p->rpath_orig) return 0; + 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 0; + s = t+1; + n++; + } + if (n > SSIZE_MAX/PATH_MAX) return 0; + + 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, $ORIGIN can be processed safely + * since the library's pathname came from a trusted source + * (either system paths or a call to dlopen). */ + if (libc.secure) + return 0; + l = readlink("/proc/self/exe", buf, buf_size); + if (l == -1) switch (errno) { + case ENOENT: + case ENOTDIR: + case EACCES: + break; + default: + return -1; + } + if (l >= buf_size) + return 0; + buf[l] = 0; + origin = buf; + } else { + origin = p->name; + } + t = strrchr(origin, '/'); + l = t ? t-origin : 0; + p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1); + if (!p->rpath) return -1; + + d = p->rpath; + s = p->rpath_orig; + while ((t=strchr(s, '$'))) { + 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}; + 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 = p->strings + dyn[DT_RPATH]; + if (dyn[0]&(1<rpath_orig = p->strings + dyn[DT_RUNPATH]; + if (dyn[0]&(1<got = laddr(p, dyn[DT_PLTGOT]); 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 = laddr(p, *dyn); +} + +static size_t count_syms(struct dso *p) +{ + if (p->hashtab) return p->hashtab[1]; + + size_t nsym, i; + uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4); + uint32_t *hashval; + for (i = nsym = 0; i < p->ghashtab[0]; i++) { + if (buckets[i] > nsym) + nsym = buckets[i]; + } + if (nsym) { + hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]); + do nsym++; + while (!(*hashval++ & 1)); + } + return nsym; } -static struct dso *load_library(const char *name) +static void *dl_mmap(size_t n) +{ + void *p; + int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE; +#ifdef SYS_mmap2 + p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0); +#else + p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0); +#endif + return p == MAP_FAILED ? 0 : p; +} + +static void makefuncdescs(struct dso *p) +{ + static int self_done; + size_t nsym = count_syms(p); + size_t i, size = nsym * sizeof(*p->funcdescs); + + if (!self_done) { + p->funcdescs = dl_mmap(size); + self_done = 1; + } else { + p->funcdescs = malloc(size); + } + if (!p->funcdescs) { + if (!runtime) a_crash(); + error("Error allocating function descriptors for %s", p->name); + longjmp(*rtld_fail, 1); + } + for (i=0; isyms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) { + p->funcdescs[i].addr = laddr(p, p->syms[i].st_value); + p->funcdescs[i].got = p->got; + } else { + p->funcdescs[i].addr = 0; + p->funcdescs[i].got = 0; + } + } +} + +static struct dso *load_library(const char *name, struct dso *needed_by) { char buf[2*NAME_MAX+2]; const char *pathname; - unsigned char *base, *map; - size_t dyno, map_len; - struct dso *p; + unsigned char *map; + struct dso *p, temp_dso = {0}; int fd; struct stat st; + size_t alloc_size; + 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') { @@ -410,20 +876,36 @@ static struct dso *load_library(const char *name) char *z = strchr(name, '.'); if (z) { size_t l = z-name; - for (rp=reserved; *rp && memcmp(name+3, rp, l-3); rp+=strlen(rp)+1); + for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1); if (*rp) { - if (!libc->prev) { - tail->next = libc; - libc->prev = tail; - tail = libc->next ? libc->next : libc; + if (ldd_mode) { + /* Track which names have been resolved + * and only report each one once. */ + static unsigned reported; + unsigned mask = 1U<<(rp-reserved); + if (!(reported & mask)) { + reported |= mask; + dprintf(1, "\t%s => %s (%p)\n", + name, ldso.name, + ldso.base); + } } - return libc; + 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; + } + return &ldso; + } if (strchr(name, '/')) { pathname = name; - fd = open(name, O_RDONLY); + fd = open(name, O_RDONLY|O_CLOEXEC); } else { /* Search for the name to see if it's already loaded */ for (p=head->next; p; p=p->next) { @@ -434,19 +916,47 @@ static struct dso *load_library(const char *name) } if (strlen(name) > NAME_MAX) return 0; fd = -1; - if (r_path) fd = path_open(name, r_path, buf, sizeof buf); - if (fd < 0 && env_path) fd = path_open(name, env_path, buf, sizeof buf); - if (fd < 0) { + if (env_path) fd = path_open(name, env_path, 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 == -1) { if (!sys_path) { - FILE *f = fopen(ETC_LDSO_PATH, "r"); + char *prefix = 0; + size_t prefix_len; + if (ldso.name[0]=='/') { + char *s, *t, *z; + for (s=t=z=ldso.name; *s; s++) + if (*s=='/') z=t, t=s; + prefix_len = z-ldso.name; + if (prefix_len < PATH_MAX) + prefix = ldso.name; + } + if (!prefix) { + prefix = ""; + prefix_len = 0; + } + char etc_ldso_path[prefix_len + 1 + + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"]; + snprintf(etc_ldso_path, sizeof etc_ldso_path, + "%.*s/etc/ld-musl-" LDSO_ARCH ".path", + (int)prefix_len, prefix); + FILE *f = fopen(etc_ldso_path, "rbe"); if (f) { - if (getline(&sys_path, (size_t[1]){0}, f) > 0) - sys_path[strlen(sys_path)-1]=0; + if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) { + free(sys_path); + sys_path = ""; + } fclose(f); + } else if (errno != ENOENT) { + sys_path = ""; } } - 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); + if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib"; + fd = path_open(name, sys_path, buf, sizeof buf); } pathname = buf; } @@ -460,40 +970,70 @@ static struct dso *load_library(const char *name) /* 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; + if (!p->shortname && pathname != name) + p->shortname = strrchr(p->name, '/')+1; close(fd); p->refcnt++; return p; } } - map = map_library(fd, &map_len, &base, &dyno); + map = noload ? 0 : map_library(fd, &temp_dso); close(fd); if (!map) return 0; - p = calloc(1, sizeof *p + strlen(pathname) + 1); + + /* Allocate storage for the new DSO. When there is TLS, this + * storage must include a reservation for all pre-existing + * threads to obtain copies of both the new TLS, and an + * extended DTV capable of storing an additional slot for + * the newly-loaded DSO. */ + alloc_size = sizeof *p + strlen(pathname) + 1; + if (runtime && temp_dso.tls_image) { + size_t per_th = temp_dso.tls_size + temp_dso.tls_align + + sizeof(void *) * (tls_cnt+3); + n_th = libc.threads_minus_1 + 1; + if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX; + else alloc_size += n_th * per_th; + } + p = calloc(1, alloc_size); if (!p) { - munmap(map, map_len); + unmap_library(&temp_dso); return 0; } - - p->map = map; - p->map_len = map_len; - p->base = base; - p->dynv = (void *)(base + dyno); + memcpy(p, &temp_dso, sizeof temp_dso); decode_dyn(p); - 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. */ if (pathname != name) p->shortname = strrchr(p->name, '/')+1; + if (p->tls_image) { + 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; +#else + tls_offset += p->tls_size + p->tls_align - 1; + tls_offset -= (tls_offset + (uintptr_t)p->tls_image) + & (p->tls_align-1); + p->tls_offset = tls_offset; +#endif + p->new_dtv = (void *)(-sizeof(size_t) & + (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t))); + p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1)); + } tail->next = p; p->prev = tail; tail = p; - if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, base); + if (DL_FDPIC) makefuncdescs(p); + + if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base); return p; } @@ -503,31 +1043,23 @@ 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)", + 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; + if (runtime) longjmp(*rtld_fail, 1); continue; } if (runtime) { tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2)); - if (!tmp) longjmp(rtld_fail, 1); + if (!tmp) longjmp(*rtld_fail, 1); tmp[ndeps++] = dep; tmp[ndeps] = 0; *deps = tmp; } } - r_path = 0; } } @@ -536,11 +1068,11 @@ 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); + load_library(s, 0); *z = tmp; } } @@ -550,45 +1082,62 @@ 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 - do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ], + if (NEED_MIPS_GOT_RELOCS) + do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT])); + do_relocs(p, laddr(p, 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; - } -} + do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2); + do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3); + + if (head != &ldso && p->relro_start != p->relro_end && + mprotect(laddr(p, 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); + } -static void free_all(struct dso *p) -{ - struct dso *n; - while (p) { - n = p->next; - if (p->map && p!=libc && p!=head) free(p); - p = n; + p->relocated = 1; } } -static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride) -{ - for (; cnt--; ph = (void *)((char *)ph + stride)) - if (ph->p_type == PT_DYNAMIC) - return ph->p_vaddr; - return 0; -} - -static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p) +static void kernel_mapped_dso(struct dso *p) { - size_t min_addr = -1, max_addr = 0; - for (; cnt--; ph = (void *)((char *)ph + stride)) { + size_t min_addr = -1, max_addr = 0, cnt; + Phdr *ph = p->phdr; + for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) { + if (ph->p_type == PT_DYNAMIC) { + 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; + } if (ph->p_type != PT_LOAD) continue; if (ph->p_vaddr < min_addr) min_addr = ph->p_vaddr; @@ -599,104 +1148,351 @@ static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p) max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE; p->map = p->base + min_addr; p->map_len = max_addr - min_addr; + p->kernel_mapped = 1; +} + +static void do_fini() +{ + struct dso *p; + 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<prev) { - if (p->constructed) return; - decode_vec(p->dynv, dyn, DYN_CNT); - if (dyn[0] & (1<base + dyn[DT_FINI])); - if (dyn[0] & (1<base + dyn[DT_INIT]))(); + if (p->constructed) continue; p->constructed = 1; + decode_vec(p->dynv, dyn, DYN_CNT); + if (dyn[0] & ((1<fini_next = fini_head; + fini_head = p; + } +#ifndef NO_LEGACY_INITFINI + if ((dyn[0] & (1<next) { + if (!p->tls_id || !self->dtv[p->tls_id]) continue; + memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len); + memset((char *)self->dtv[p->tls_id]+p->tls_len, 0, + p->tls_size - p->tls_len); + if (p->tls_id == (size_t)self->dtv[0]) break; } } -void _dl_debug_state(void) +void *__copy_tls(unsigned char *mem) { + pthread_t td; + struct dso *p; + void **dtv; + +#ifdef TLS_ABOVE_TP + 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); + + for (p=head; p; p=p->next) { + if (!p->tls_id) continue; + dtv[p->tls_id] = mem + p->tls_offset; + 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; + + for (p=head; p; p=p->next) { + if (!p->tls_id) continue; + dtv[p->tls_id] = mem - p->tls_offset; + memcpy(dtv[p->tls_id], p->tls_image, p->tls_len); + } +#endif + dtv[0] = (void *)tls_cnt; + td->dtv = td->dtv_copy = dtv; + return td; } -void *__dynlink(int argc, char **argv) +__attribute__((__visibility__("hidden"))) +void *__tls_get_new(size_t *v) { - size_t aux[AUX_CNT] = {0}; + pthread_t self = __pthread_self(); + + /* Block signals to make accessing new TLS async-signal-safe */ + sigset_t set; + __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 + * is able to request the Nth entry of the DTV, the DSO list + * must be valid at least that far out and it was synchronized + * at program startup or by an already-completed call to dlopen. */ + struct dso *p; + for (p=head; p->tls_id != v[0]; p=p->next); + + /* Get new DTV space from new DSO if needed */ + if (v[0] > (size_t)self->dtv[0]) { + void **newdtv = p->new_dtv + + (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1); + memcpy(newdtv, self->dtv, + ((size_t)self->dtv[0]+1) * sizeof(void *)); + newdtv[0] = (void *)v[0]; + self->dtv = self->dtv_copy = newdtv; + } + + /* 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() +{ + libc.tls_size = ALIGN( + (1+tls_cnt) * sizeof(void *) + + tls_offset + + sizeof(struct pthread) + + tls_align * 2, + tls_align); +} + +/* 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) +{ + if (DL_FDPIC) { + void *p1 = (void *)sp[-2]; + void *p2 = (void *)sp[-1]; + if (!p1) { + size_t *auxv, aux[AUX_CNT]; + for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++; + decode_vec(auxv, aux, AUX_CNT); + if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE]; + else ldso.base = (void *)(aux[AT_PHDR] & -4096); + } + app_loadmap = p2 ? p1 : 0; + ldso.loadmap = p2 ? p2 : p1; + ldso.base = laddr(&ldso, 0); + } else { + ldso.base = base; + } + Ehdr *ehdr = (void *)ldso.base; + ldso.name = ldso.shortname = "libc.so"; + ldso.global = 1; + ldso.phnum = ehdr->e_phnum; + ldso.phdr = laddr(&ldso, ehdr->e_phoff); + ldso.phentsize = ehdr->e_phentsize; + kernel_mapped_dso(&ldso); + decode_dyn(&ldso); + + if (DL_FDPIC) makefuncdescs(&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 = laddr(&ldso, 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], ldso.syms)) 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); + if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp); + else ((stage3_func)laddr(&ldso, 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; - - /* 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); - + int argc = *sp; + char **argv = (void *)(sp+1); + char **argv_orig = argv; + char **envp = argv+argc+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); + __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(); + } /* 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; - } - - /* 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; - } - - /* 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; - find_map_range((void *)(aux[AT_BASE]+ehdr->e_phoff), - ehdr->e_phnum, ehdr->e_phentsize, lib); - lib->dynv = (void *)(lib->base + find_dyn( - (void *)(aux[AT_BASE]+ehdr->e_phoff), - ehdr->e_phnum, ehdr->e_phentsize)); - decode_dyn(lib); - - if (aux[AT_PHDR]) { + if (!libc.secure) { + env_path = getenv("LD_LIBRARY_PATH"); + env_preload = getenv("LD_PRELOAD"); + } + + /* 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. */ - phdr = (void *)aux[AT_PHDR]; + 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; + } } - 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])); - find_map_range((void *)aux[AT_PHDR], - aux[AT_PHNUM], aux[AT_PHENT], app); + if (DL_FDPIC) app.loadmap = app_loadmap; + if (app.tls_size) app.tls_image = laddr(&app, tls_image); + if (interp_off) ldso.name = laddr(&app, interp_off); + if ((aux[0] & (1UL<= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1; - *argv++ = (void *)-1; - if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1; + argv++; + while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') { + char *opt = argv[0]+2; + *argv++ = (void *)-1; + if (!*opt) { + break; + } else if (!memcmp(opt, "list", 5)) { + ldd_mode = 1; + } else if (!memcmp(opt, "library-path", 12)) { + if (opt[12]=='=') env_path = opt+13; + else if (opt[12]) *argv = 0; + else if (*argv) env_path = *argv++; + } else if (!memcmp(opt, "preload", 7)) { + if (opt[7]=='=') env_preload = opt+8; + else if (opt[7]) *argv = 0; + else if (*argv) env_preload = *argv++; + } else { + argv[0] = 0; + } + } + argv[-1] = (void *)(argc - (argv-argv_orig)); 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 [options] [--] pathname%s\n", + __libc_get_version(), ldname, ldd_mode ? "" : " [args]"); _exit(1); } @@ -706,135 +1502,201 @@ void *__dynlink(int argc, char **argv) _exit(1); } runtime = 1; - ehdr = (void *)map_library(fd, &app->map_len, &app->base, &dyno); + 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]; - app->dynv = (void *)(app->base + dyno); - aux[AT_ENTRY] = 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; insegs = 1; + app.loadmap->segs[0].addr = (size_t)app.map; + app.loadmap->segs[0].p_vaddr = (size_t)app.map + - (size_t)app.base; + app.loadmap->segs[0].p_memsz = app.map_len; + } + argv[-3] = (void *)app.loadmap; } - app->global = 1; - app->constructed = 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; - phdr = (void *)(vdso_base + ehdr->e_phoff); + 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; - libc = 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->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]); - ehdr = (void *)lib->base; - reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff), - ehdr->e_phentsize, ehdr->e_phnum); + 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); - reloc_all(app->next); - reloc_all(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; +#endif + + /* 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 || 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 { + 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; -#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.bp = dl_debug_state; debug.head = head; - debug.base = lib->base; + debug.base = ldso.base; debug.state = 0; _dl_debug_state(); - if (ssp_used) __init_ssp(auxv); - - do_init_fini(tail); - - if (!rtld_used) { - free_all(head); - free(sys_path); - reclaim((void *)builtin_dsos, 0, sizeof builtin_dsos); - } - + __init_libc(envp, argv[0]); + atexit(do_fini); errno = 0; - return (void *)aux[AT_ENTRY]; + + CRTJMP((void *)aux[AT_ENTRY], argv-1); + for(;;); } void *dlopen(const char *file, int mode) { - struct dso *volatile p, *orig_tail = tail, *next; + struct dso *volatile p, *orig_tail, *next; + size_t orig_tls_cnt, orig_tls_offset, orig_tls_align; size_t i; int cs; + jmp_buf jb; if (!file) return head; pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); pthread_rwlock_wrlock(&lock); + __inhibit_ptc(); + + p = 0; + orig_tls_cnt = tls_cnt; + orig_tls_offset = tls_offset; + orig_tls_align = tls_align; + orig_tail = tail; + noload = mode & RTLD_NOLOAD; - if (setjmp(rtld_fail)) { + rtld_fail = &jb; + if (setjmp(*rtld_fail)) { /* Clean up anything new that was (partially) loaded */ - if (p->deps) for (i=0; p->deps[i]; i++) + if (p && p->deps) for (i=0; p->deps[i]; i++) if (p->deps[i]->global < 0) p->deps[i]->global = 0; 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; + } + free(p->funcdescs); + if (p->rpath != p->rpath_orig) + free(p->rpath); free(p->deps); + unmap_library(p); free(p); } + tls_cnt = orig_tls_cnt; + tls_offset = orig_tls_offset; + tls_align = orig_tls_align; tail = orig_tail; tail->next = 0; p = 0; - errflag = 1; goto end; - } else p = load_library(file); + } else p = load_library(file, head); if (!p) { - snprintf(errbuf, sizeof errbuf, - "Error loading shared library %s: %m", file); - errflag = 1; + error(noload ? + "Library %s is not already loaded" : + "Error loading shared library %s: %m", + file); goto end; } @@ -858,102 +1720,130 @@ void *dlopen(const char *file, int mode) p->global = 1; } - if (ssp_used) __init_ssp(auxv); - + update_tls_size(); _dl_debug_state(); - - do_init_fini(tail); + orig_tail = tail; end: + __release_ptc(); + if (p) gencnt++; pthread_rwlock_unlock(&lock); + if (p) do_init_fini(orig_tail); pthread_setcancelstate(cs, 0); return p; } +static int invalid_dso_handle(void *h) +{ + struct dso *p; + for (p=head; p; p=p->next) if (h==p) return 0; + error("Invalid library handle %p", (void *)h); + return 1; +} + +static void *addr2dso(size_t a) +{ + struct dso *p; + for (p=head; p; p=p->next) { + if (DL_FDPIC && p->loadmap) { + size_t i; + for (i=0; iloadmap->nsegs; i++) { + if (a-p->loadmap->segs[i].p_vaddr + < p->loadmap->segs[i].p_memsz) + return p; + } + i = count_syms(p); + if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs)) + return p; + } else { + if (a-(size_t)p->map < p->map_len) + return p; + } + } + return 0; +} + +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 == RTLD_NEXT) { - for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next); - if (!p) p=head; - void *res = find_sym(p->next, s, 0); - if (!res) goto failed; - return res; - } - if (p == head || p == RTLD_DEFAULT) { - void *res = find_sym(head, s, 0); - if (!res) goto failed; - return res; - } - if (p->ghashtab) { + if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) { + if (p == RTLD_DEFAULT) { + p = head; + } else if (p == RTLD_NEXT) { + p = addr2dso((size_t)ra); + if (!p) p=head; + p = p->next; + } + struct symdef def = find_sym(p, s, 0); + 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}); + if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC) + return def.dso->funcdescs + (def.sym - def.dso->syms); + return laddr(def.dso, def.sym->st_value); + } + if (invalid_dso_handle(p)) + return 0; + 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); } + if (sym && (sym->st_info&0xf) == STT_TLS) + return __tls_get_addr((size_t []){p->tls_id, sym->st_value}); + if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC) + return p->funcdescs + (sym - p->syms); 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]); } + if (sym && (sym->st_info&0xf) == STT_TLS) + return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value}); + if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC) + return p->deps[i]->funcdescs + (sym - p->deps[i]->syms); 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; } -int __dladdr(void *addr, Dl_info *info) +int __dladdr(const void *addr, Dl_info *info) { struct dso *p; Sym *sym; uint32_t nsym; char *strings; - size_t i; void *best = 0; char *bestname; pthread_rwlock_rdlock(&lock); - for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next); + p = addr2dso((size_t)addr); pthread_rwlock_unlock(&lock); if (!p) return 0; sym = p->syms; strings = p->strings; - if (p->hashtab) { - nsym = p->hashtab[1]; - } else { - uint32_t *buckets; - 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++) { - if (buckets[i] > nsym) - nsym = buckets[i]; - } - if (nsym) { - nsym -= p->ghashtab[1]; - hashval = buckets + p->ghashtab[0] + nsym; - do nsym++; - while (!(*hashval++ & 1)); - } - } + nsym = count_syms(p); for (; nsym; nsym--, sym++) { - if (sym->st_shndx && sym->st_value + 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; @@ -973,7 +1863,8 @@ int __dladdr(void *addr, Dl_info *info) return 1; } -void *__dlsym(void *p, const char *s, void *ra) +__attribute__((__visibility__("hidden"))) +void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) { void *res; pthread_rwlock_rdlock(&lock); @@ -981,29 +1872,115 @@ void *__dlsym(void *p, const char *s, void *ra) pthread_rwlock_unlock(&lock); return res; } + +int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data) +{ + struct dso *current; + struct dl_phdr_info info; + int ret = 0; + for(current = head; current;) { + info.dlpi_addr = (uintptr_t)current->base; + info.dlpi_name = current->name; + info.dlpi_phdr = current->phdr; + info.dlpi_phnum = current->phnum; + info.dlpi_adds = gencnt; + info.dlpi_subs = 0; + info.dlpi_tls_modid = current->tls_id; + info.dlpi_tls_data = current->tls_image; + + ret = (callback)(&info, sizeof (info), data); + + if (ret != 0) break; + + pthread_rwlock_rdlock(&lock); + current = current->next; + pthread_rwlock_unlock(&lock); + } + return ret; +} #else +static int invalid_dso_handle(void *h) +{ + 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 *p, const char *s, void *ra) +void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) { + error("Symbol not found: %s", s); return 0; } -int __dladdr (void *addr, Dl_info *info) +int __dladdr (const void *addr, Dl_info *info) { return 0; } #endif +int __dlinfo(void *dso, int req, void *res) +{ + if (invalid_dso_handle(dso)) return -1; + if (req != RTLD_DI_LINKMAP) { + error("Unsupported request %d", req); + return -1; + } + *(struct link_map **)res = dso; + return 0; +} + 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 0; + 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; }