X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=cab30089e5d1cc0ceeb58f50d1f81805f1ad11b7;hb=bd275378d35b3535bc8b8321780b00e486c36d96;hp=42930adfb44a6a46772addcedd0ad147402c9fdf;hpb=9bbddf730f7837cf87f4c789fbb41a312e295d6c;p=musl diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 42930adf..cab30089 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -42,7 +42,11 @@ struct td_index { }; struct dso { +#if DL_FDPIC + struct fdpic_loadmap *loadmap; +#else unsigned char *base; +#endif char *name; size_t *dynv; struct dso *next, *prev; @@ -75,6 +79,16 @@ struct dso { 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[]; }; @@ -112,6 +126,8 @@ static struct debug debug; 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; @@ -122,6 +138,22 @@ static int dl_strcmp(const char *l, const 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) { size_t i; @@ -156,7 +188,7 @@ static uint32_t gnu_hash(const char *s0) const unsigned char *s = (void *)s0; uint_fast32_t h = 5381; for (; *s; s++) - h = h*33 + *s; + h += h*32 + *s; return h; } @@ -174,32 +206,39 @@ static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso) 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 *syms = dso->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); @@ -268,15 +313,18 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri } for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) { - if (skip_relative && IS_RELATIVE(rel[1])) continue; + 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 = (void *)(base + rel[0]); + reloc_addr = laddr(dso, rel[0]); if (sym_index) { sym = syms + sym_index; name = strings + sym->st_name; ctx = type==REL_COPY ? head->next : head; - def = find_sym(ctx, name, type==REL_PLT); + 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", @@ -305,7 +353,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri addend = *reloc_addr; } - sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0; + 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) { @@ -332,11 +380,20 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri *(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; + *reloc_addr = tls_val + addend - DTP_OFFSET; break; #ifdef TLS_ABOVE_TP case REL_TPOFF: @@ -400,8 +457,8 @@ 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; @@ -413,6 +470,7 @@ static void reclaim_gaps(struct dso *dso) 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; @@ -422,6 +480,44 @@ 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 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)]; @@ -429,6 +525,7 @@ static void *map_library(int fd, struct dso *dso) 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, *ph0; @@ -472,6 +569,7 @@ static void *map_library(int fd, struct dso *dso) 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; @@ -484,6 +582,33 @@ static void *map_library(int fd, struct dso *dso) } } 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; @@ -495,6 +620,8 @@ static void *map_library(int fd, struct dso *dso) * 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) 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) { @@ -523,34 +650,34 @@ 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; } - dso->map = map; - dso->map_len = map_len; +done_mapping: dso->base = base; - dso->dynv = (void *)(base+dyn); - if (dso->tls_size) dso->tls_image = (void *)(base+tls_image); + 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: - if (map!=MAP_FAILED) munmap(map, map_len); + if (map!=MAP_FAILED) unmap_library(dso); free(allocated_buf); return 0; } @@ -650,18 +777,79 @@ static void decode_dyn(struct dso *p) { 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]); + p->rpath_orig = p->strings + dyn[DT_RPATH]; if (dyn[0]&(1<rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]); + p->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 = (void *)(p->base + *dyn); + 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 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) @@ -808,7 +996,7 @@ static struct dso *load_library(const char *name, struct dso *needed_by) } p = calloc(1, alloc_size); if (!p) { - munmap(map, temp_dso.map_len); + unmap_library(&temp_dso); return 0; } memcpy(p, &temp_dso, sizeof temp_dso); @@ -843,6 +1031,8 @@ static struct dso *load_library(const char *name, struct dso *needed_by) p->prev = tail; tail = p; + if (DL_FDPIC) makefuncdescs(p); + if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base); return p; @@ -919,14 +1109,15 @@ static void reloc_all(struct dso *p) if (p->relocated) continue; decode_vec(p->dynv, dyn, DYN_CNT); 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], + 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); + 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(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) { + 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); @@ -942,7 +1133,7 @@ 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; @@ -969,12 +1160,12 @@ static void do_fini() 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]))(); + fpaddr(p, dyn[DT_FINI])(); #endif } } @@ -997,11 +1188,11 @@ static void do_init_fini(struct dso *p) } #ifndef NO_LEGACY_INITFINI if ((dyn[0] & (1<base + dyn[DT_INIT]))(); + fpaddr(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) { @@ -1012,6 +1203,11 @@ static void do_init_fini(struct dso *p) if (need_locking) pthread_mutex_unlock(&init_fini_lock); } +void __libc_start_init(void) +{ + do_init_fini(tail); +} + static void dl_debug_state(void) { } @@ -1077,7 +1273,7 @@ void *__tls_get_new(size_t *v) __block_all_sigs(&set); if (v[0]<=(size_t)self->dtv[0]) { __restore_sigs(&set); - return (char *)self->dtv[v[0]]+v[1]; + return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET; } /* This is safe without any locks held because, if the caller @@ -1110,7 +1306,7 @@ void *__tls_get_new(size_t *v) if (p->tls_id == v[0]) break; } __restore_sigs(&set); - return mem + v[1]; + return mem + v[1] + DTP_OFFSET; } static void update_tls_size() @@ -1136,28 +1332,45 @@ static void update_tls_size() void __dls2(unsigned char *base, size_t *sp) { - Ehdr *ehdr = (void *)base; - ldso.base = base; + 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 = (void *)(base + ehdr->e_phoff); + 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 = (void *)(base+dyn[DT_REL]); + 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])) symbolic_rel_cnt++; + 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; @@ -1171,7 +1384,8 @@ void __dls2(unsigned char *base, size_t *sp) * 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); + 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 @@ -1191,6 +1405,17 @@ _Noreturn void __dls3(size_t *sp) 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. */ @@ -1199,25 +1424,11 @@ _Noreturn void __dls3(size_t *sp) a_crash(); } - /* 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); - - 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; + if (!libc.secure) { + env_path = getenv("LD_LIBRARY_PATH"); + env_preload = getenv("LD_PRELOAD"); } - libc.page_size = aux[AT_PAGESZ]; - libc.auxv = auxv; /* If the main program was already loaded by the kernel, * AT_PHDR will point to some location other than the dynamic @@ -1241,8 +1452,9 @@ _Noreturn void __dls3(size_t *sp) app.tls_align = phdr->p_align; } } - if (app.tls_size) app.tls_image = (char *)app.base + tls_image; - if (interp_off) ldso.name = (char *)app.base + interp_off; + 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<e_entry; + 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; + } /* Attach to vdso, if provided by the kernel */ if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) { @@ -1414,7 +1637,6 @@ _Noreturn void __dls3(size_t *sp) __init_libc(envp, argv[0]); atexit(do_fini); errno = 0; - do_init_fini(tail); CRTJMP((void *)aux[AT_ENTRY], argv-1); for(;;); @@ -1449,15 +1671,16 @@ void *dlopen(const char *file, int mode) 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; @@ -1517,18 +1740,40 @@ static int invalid_dso_handle(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 == head || p == RTLD_DEFAULT || p == RTLD_NEXT) { if (p == RTLD_DEFAULT) { p = head; } else if (p == RTLD_NEXT) { - for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next); + p = addr2dso((size_t)ra); if (!p) p=head; p = p->next; } @@ -1536,33 +1781,39 @@ 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; + 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 (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); } 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: error("Symbol not found: %s", s); @@ -1575,42 +1826,24 @@ int __dladdr(const void *addr, Dl_info *info) 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 = nsym = 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_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;