diff options
| -rwxr-xr-x | configure | 2 | ||||
| -rw-r--r-- | src/ldso/dynlink.c | 97 |
2 files changed, 86 insertions, 13 deletions
diff --git a/configure b/configure index 1e8b9741..11051800 100755 --- a/configure +++ b/configure @@ -268,7 +268,7 @@ fi # Some patched GCC builds have these defaults messed up... tryflag CFLAGS_AUTO -fno-stack-protector -tryldflag LDFLAGS_AUTO -Wl,--hash-style=sysv +tryldflag LDFLAGS_AUTO -Wl,--hash-style=both # Disable dynamic linking if ld is broken and can't do -Bsymbolic-functions LDFLAGS_DUMMY= diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 9692c6b0..d7d68002 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -53,6 +53,7 @@ struct dso { int refcnt; Sym *syms; uint32_t *hashtab; + uint32_t *ghashtab; char *strings; unsigned char *map; size_t map_len; @@ -95,7 +96,15 @@ static void decode_vec(size_t *v, size_t *a, size_t cnt) } } -static uint32_t hash(const char *s0) +static int search_vec(size_t *v, size_t *r, size_t key) +{ + for (; v[0]!=key; v+=2) + if (!v[0]) return 0; + *r = v[1]; + return 1; +} + +static uint32_t sysv_hash(const char *s0) { const unsigned char *s = (void *)s0; uint_fast32_t h = 0; @@ -106,7 +115,16 @@ static uint32_t hash(const char *s0) return h & 0xfffffff; } -static Sym *lookup(const char *s, uint32_t h, struct dso *dso) +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; + return h; +} + +static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso) { size_t i; Sym *syms = dso->syms; @@ -119,20 +137,61 @@ static Sym *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) +{ + 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]; + + if (!n) return 0; + + strings = dso->strings; + sym = dso->syms + n; + hashval = buckets + nbuckets + (n - hashtab[1]); + + for (h1 |= 1; ; sym++) { + h2 = *hashval++; + if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name)) + return sym; + if (h2 & 1) break; + } + + return 0; +} + #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON) #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK) static void *find_sym(struct dso *dso, const char *s, int need_def) { - uint32_t h = hash(s); + uint32_t h = 0, gh = 0; void *def = 0; - 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; + if (dso->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; + } for (; dso; dso=dso->next) { Sym *sym; if (!dso->global) continue; - sym = lookup(s, h, dso); + if (dso->ghashtab) { + if (!gh) gh = gnu_hash(s); + sym = gnu_lookup(s, gh, dso); + } 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)) { @@ -325,8 +384,11 @@ static void decode_dyn(struct dso *p) size_t dyn[DYN_CNT] = {0}; decode_vec(p->dynv, dyn, DYN_CNT); p->syms = (void *)(p->base + dyn[DT_SYMTAB]); - p->hashtab = (void *)(p->base + dyn[DT_HASH]); p->strings = (void *)(p->base + dyn[DT_STRTAB]); + if (dyn[0]&(1<<DT_HASH)) + p->hashtab = (void *)(p->base + dyn[DT_HASH]); + if (search_vec(p->dynv, dyn, DT_GNU_HASH)) + p->ghashtab = (void *)(p->base + *dyn); } static struct dso *load_library(const char *name) @@ -788,7 +850,7 @@ end: static void *do_dlsym(struct dso *p, const char *s, void *ra) { size_t i; - uint32_t h; + uint32_t h = 0, gh = 0; Sym *sym; if (p == RTLD_NEXT) { for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next); @@ -802,12 +864,23 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra) if (!res) goto failed; return res; } - h = hash(s); - sym = lookup(s, h, p); + if (p->ghashtab) { + gh = gnu_hash(s); + sym = gnu_lookup(s, gh, p); + } else { + h = sysv_hash(s); + sym = sysv_lookup(s, h, p); + } if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) return p->base + sym->st_value; if (p->deps) for (i=0; p->deps[i]; i++) { - sym = lookup(s, h, p->deps[i]); + if (p->deps[i]->ghashtab) { + if (!gh) gh = gnu_hash(s); + sym = gnu_lookup(s, h, p->deps[i]); + } else { + if (!h) h = sysv_hash(s); + sym = sysv_lookup(s, h, p->deps[i]); + } if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) return p->deps[i]->base + sym->st_value; } |