X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=8ff8e6965f34aae9733bc01c210aed846d1bbd2b;hp=a171df977196c708c65819d5de885112d2f98644;hb=c91aa03d2488ef2c48276510dec360ed9582e861;hpb=649cec5f9868070b4d350b861ee7f68b03a552a8

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index a171df97..8ff8e696 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -16,14 +17,15 @@
 #include <pthread.h>
 #include <ctype.h>
 #include <dlfcn.h>
+#include "pthread_impl.h"
+#include "libc.h"
+#undef libc
 
 static int errflag;
 static char errbuf[128];
 
 #ifdef SHARED
 
-#include "reloc.h"
-
 #if ULONG_MAX == 0xffffffff
 typedef Elf32_Ehdr Ehdr;
 typedef Elf32_Phdr Phdr;
@@ -55,6 +57,7 @@ struct dso {
 	int refcnt;
 	Sym *syms;
 	uint32_t *hashtab;
+	uint32_t *ghashtab;
 	char *strings;
 	unsigned char *map;
 	size_t map_len;
@@ -64,21 +67,28 @@ struct dso {
 	char relocated;
 	char constructed;
 	struct dso **deps;
+	void *tls_image;
+	size_t tls_len, tls_size, tls_align, tls_id;
 	char *shortname;
 	char buf[];
 };
 
+#include "reloc.h"
+
 void __init_ssp(size_t *);
+void *__install_initial_tls(void *);
 
 static struct dso *head, *tail, *libc;
 static char *env_path, *sys_path, *r_path;
-static int rtld_used;
 static int ssp_used;
 static int runtime;
 static int ldd_mode;
+static int ldso_fail;
 static jmp_buf rtld_fail;
 static pthread_rwlock_t lock;
 static struct debug debug;
+static size_t *auxv;
+static size_t tls_cnt, tls_size;
 
 struct debug *_dl_debug_addr = &debug;
 
@@ -94,7 +104,15 @@ 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;
@@ -105,9 +123,21 @@ static uint32_t hash(const char *s0)
 	return h & 0xfffffff;
 }
 
-static Sym *lookup(const char *s, uint32_t h, Sym *syms, uint32_t *hashtab, char *strings)
+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;
+	uint32_t *hashtab = dso->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))
 			return syms+i;
@@ -115,20 +145,57 @@ static Sym *lookup(const char *s, uint32_t h, Sym *syms, uint32_t *hashtab, char
 	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 == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
+	} else {
+		h = sysv_hash(s);
+		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->syms, dso->hashtab, dso->strings);
+		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)) {
@@ -140,8 +207,11 @@ static void *find_sym(struct dso *dso, const char *s, int need_def)
 	return def;
 }
 
-static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t stride, Sym *syms, char *strings, struct dso *dso)
+static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 {
+	unsigned char *base = dso->base;
+	Sym *syms = dso->syms;
+	char *strings = dso->strings;
 	Sym *sym;
 	const char *name;
 	size_t sym_val, sym_size;
@@ -157,7 +227,7 @@ static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t
 		if (sym_index) {
 			sym = syms + sym_index;
 			name = strings + sym->st_name;
-			ctx = IS_COPY(type) ? dso->next : dso;
+			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,
@@ -165,9 +235,12 @@ static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t
 					dso->name, name);
 				if (runtime) longjmp(rtld_fail, 1);
 				dprintf(2, "%s\n", errbuf);
-				_exit(127);
+				ldso_fail = 1;
+				continue;
 			}
 			sym_size = sym->st_size;
+		} else {
+			sym_val = sym_size = 0;
 		}
 		do_single_reloc(reloc_addr, type, sym_val, sym_size, base, rel[2]);
 	}
@@ -204,7 +277,7 @@ static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phc
 	}
 }
 
-static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dynp)
+static void *map_library(int fd, struct dso *dso)
 {
 	Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 	size_t phsize;
@@ -216,6 +289,7 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy
 	unsigned prot;
 	unsigned char *map, *base;
 	size_t dyn;
+	size_t tls_image=0;
 	size_t i;
 
 	ssize_t l = read(fd, buf, sizeof buf);
@@ -232,6 +306,12 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy
 	for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 		if (ph->p_type == PT_DYNAMIC)
 			dyn = ph->p_vaddr;
+		if (ph->p_type == PT_TLS) {
+			tls_image = ph->p_vaddr;
+			dso->tls_align = ph->p_align;
+			dso->tls_len = ph->p_filesz;
+			dso->tls_size = ph->p_memsz;
+		}
 		if (ph->p_type != PT_LOAD) continue;
 		if (ph->p_vaddr < addr_min) {
 			addr_min = ph->p_vaddr;
@@ -286,9 +366,11 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy
 		}
 	if (!runtime) reclaim_gaps(base, (void *)((char *)buf + eh->e_phoff),
 		eh->e_phentsize, eh->e_phnum);
-	*lenp = map_len;
-	*basep = base;
-	*dynp = dyn;
+	dso->map = map;
+	dso->map_len = map_len;
+	dso->base = base;
+	dso->dynv = (void *)(base+dyn);
+	if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 	return map;
 error:
 	munmap(map, map_len);
@@ -305,7 +387,7 @@ static int path_open(const char *name, const char *search, char *buf, size_t buf
 		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;
+		if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 		s += l;
 	}
 }
@@ -315,8 +397,11 @@ 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)
@@ -325,7 +410,7 @@ static struct dso *load_library(const char *name)
 	const char *pathname;
 	unsigned char *base, *map;
 	size_t dyno, map_len;
-	struct dso *p;
+	struct dso *p, temp_dso = {0};
 	int fd;
 	struct stat st;
 
@@ -349,7 +434,7 @@ static struct dso *load_library(const char *name)
 	}
 	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) {
@@ -364,7 +449,7 @@ static struct dso *load_library(const char *name)
 		if (fd < 0 && env_path) fd = path_open(name, env_path, buf, sizeof buf);
 		if (fd < 0) {
 			if (!sys_path) {
-				FILE *f = fopen(ETC_LDSO_PATH, "r");
+				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;
@@ -392,21 +477,21 @@ static struct dso *load_library(const char *name)
 			return p;
 		}
 	}
-	map = map_library(fd, &map_len, &base, &dyno);
+	map = map_library(fd, &temp_dso);
 	close(fd);
 	if (!map) return 0;
-	p = calloc(1, sizeof *p + strlen(pathname) + 1);
+	p = malloc(sizeof *p + strlen(pathname) + 1);
 	if (!p) {
 		munmap(map, map_len);
 		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);
-
+	if (p->tls_image) {
+		p->tls_id = ++tls_cnt;
+		tls_size += p->tls_size + p->tls_align + 8*sizeof(size_t) - 1
+			& -4*sizeof(size_t);
+	}
 	p->dev = st.st_dev;
 	p->ino = st.st_ino;
 	p->refcnt = 1;
@@ -442,7 +527,8 @@ static void load_deps(struct dso *p)
 					p->strings + p->dynv[i+1], p->name);
 				if (runtime) longjmp(rtld_fail, 1);
 				dprintf(2, "%s\n", errbuf);
-				_exit(127);
+				ldso_fail = 1;
+				continue;
 			}
 			if (runtime) {
 				tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
@@ -481,12 +567,13 @@ static void reloc_all(struct dso *p)
 	for (; p; p=p->next) {
 		if (p->relocated) continue;
 		decode_vec(p->dynv, dyn, DYN_CNT);
-		do_relocs(p->base, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
-			2+(dyn[DT_PLTREL]==DT_RELA), p->syms, p->strings, head);
-		do_relocs(p->base, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ],
-			2, p->syms, p->strings, head);
-		do_relocs(p->base, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ],
-			3, p->syms, p->strings, head);
+#ifdef NEED_ARCH_RELOCS
+		do_arch_relocs(p, head);
+#endif
+		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);
 		p->relocated = 1;
 	}
 }
@@ -496,7 +583,7 @@ static void free_all(struct dso *p)
 	struct dso *n;
 	while (p) {
 		n = p->next;
-		if (p->map) free(p);
+		if (p->map && p!=libc && p!=head) free(p);
 		p = n;
 	}
 }
@@ -509,6 +596,22 @@ static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
 	return 0;
 }
 
+static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p)
+{
+	size_t min_addr = -1, max_addr = 0;
+	for (; cnt--; ph = (void *)((char *)ph + stride)) {
+		if (ph->p_type != PT_LOAD) continue;
+		if (ph->p_vaddr < min_addr)
+			min_addr = ph->p_vaddr;
+		if (ph->p_vaddr+ph->p_memsz > max_addr)
+			max_addr = ph->p_vaddr+ph->p_memsz;
+	}
+	min_addr &= -PAGE_SIZE;
+	max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
+	p->map = p->base + min_addr;
+	p->map_len = max_addr - min_addr;
+}
+
 static void do_init_fini(struct dso *p)
 {
 	size_t dyn[DYN_CNT] = {0};
@@ -527,9 +630,38 @@ void _dl_debug_state(void)
 {
 }
 
+void *__copy_tls(unsigned char *mem, size_t cnt)
+{
+	struct dso *p;
+	void **dtv = (void *)mem;
+	dtv[0] = (void *)cnt;
+	mem = (void *)(dtv + cnt + 1);
+	for (p=tail; p; p=p->prev) {
+		if (p->tls_id-1 >= cnt) continue;
+		mem += -p->tls_len & (4*sizeof(size_t)-1);
+		mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
+			& (p->tls_align-1);
+		dtv[p->tls_id] = mem;
+		memcpy(mem, p->tls_image, p->tls_len);
+		mem += p->tls_size;
+	}
+	((pthread_t)mem)->dtv = dtv;
+	return mem;
+}
+
+void *__tls_get_addr(size_t *p)
+{
+	pthread_t self = __pthread_self();
+	if ((size_t)self->dtv[0] < p[0]) {
+		// FIXME: obtain new DTV and TLS from the DSO
+		a_crash();
+	}
+	return (char *)self->dtv[p[0]] + p[1];
+}
+
 void *__dynlink(int argc, char **argv)
 {
-	size_t *auxv, aux[AUX_CNT] = {0};
+	size_t aux[AUX_CNT] = {0};
 	size_t i;
 	Phdr *phdr;
 	Ehdr *ehdr;
@@ -538,6 +670,7 @@ void *__dynlink(int argc, char **argv)
 	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++)
@@ -571,6 +704,8 @@ void *__dynlink(int argc, char **argv)
 	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));
@@ -578,6 +713,7 @@ void *__dynlink(int argc, char **argv)
 
 	if (aux[AT_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];
 		for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
@@ -585,11 +721,20 @@ void *__dynlink(int argc, char **argv)
 				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 (app->tls_size) app->tls_image = (char *)app->base + tls_image;
 		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);
 	} else {
 		int fd;
 		char *ldname = argv[0];
@@ -609,7 +754,7 @@ void *__dynlink(int argc, char **argv)
 			_exit(1);
 		}
 		runtime = 1;
-		ehdr = (void *)map_library(fd, &app->map_len, &app->base, &dyno);
+		ehdr = (void *)map_library(fd, app);
 		if (!ehdr) {
 			dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
 			_exit(1);
@@ -618,17 +763,19 @@ void *__dynlink(int argc, char **argv)
 		close(fd);
 		lib->name = ldname;
 		app->name = argv[0];
-		app->dynv = (void *)(app->base + dyno);
 		aux[AT_ENTRY] = ehdr->e_entry;
 	}
+	if (app->tls_size) {
+		app->tls_id = ++tls_cnt;
+		tls_size += app->tls_size+app->tls_align + 8*sizeof(size_t)-1
+			& -4*sizeof(size_t);
+	}
 	app->global = 1;
 	app->constructed = 1;
 	decode_dyn(app);
 
 	/* Attach to vdso, if provided by the kernel */
-	for (i=0; auxv[i]; i+=2) {
-		size_t vdso_base = auxv[i+1];
-		if (auxv[i] != AT_SYSINFO_EHDR) continue;
+	if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
 		ehdr = (void *)vdso_base;
 		phdr = (void *)(vdso_base + ehdr->e_phoff);
 		for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
@@ -642,7 +789,6 @@ void *__dynlink(int argc, char **argv)
 		decode_dyn(vdso);
 		vdso->prev = lib;
 		lib->next = vdso;
-		break;
 	}
 
 	/* Initial dso chain consists only of the app. We temporarily
@@ -673,6 +819,7 @@ void *__dynlink(int argc, char **argv)
 	reloc_all(app->next);
 	reloc_all(app);
 
+	if (ldso_fail) _exit(127);
 	if (ldd_mode) _exit(0);
 
 	/* Switch to runtime mode: any further failures in the dynamic
@@ -681,9 +828,11 @@ void *__dynlink(int argc, char **argv)
 	 * all memory used by the dynamic linker. */
 	runtime = 1;
 
+#ifndef DYNAMIC_IS_RO
 	for (i=0; app->dynv[i]; i+=2)
 		if (app->dynv[i]==DT_DEBUG)
 			app->dynv[i+1] = (size_t)&debug;
+#endif
 	debug.ver = 1;
 	debug.bp = _dl_debug_state;
 	debug.head = head;
@@ -691,16 +840,23 @@ void *__dynlink(int argc, char **argv)
 	debug.state = 0;
 	_dl_debug_state();
 
+	tls_size += sizeof(struct pthread) + 4*sizeof(size_t);
+	__libc.tls_size = tls_size;
+	__libc.tls_cnt = tls_cnt;
+	if (tls_cnt) {
+		void *mem = mmap(0, __libc.tls_size, PROT_READ|PROT_WRITE,
+			MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+		if (mem==MAP_FAILED ||
+		    !__install_initial_tls(__copy_tls(mem, tls_cnt))) {
+			dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
+				argv[0], tls_size);
+			_exit(127);
+		}
+	}
 	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);
-	}
-
 	errno = 0;
 	return (void *)aux[AT_ENTRY];
 }
@@ -761,6 +917,8 @@ void *dlopen(const char *file, int mode)
 		p->global = 1;
 	}
 
+	if (ssp_used) __init_ssp(auxv);
+
 	_dl_debug_state();
 
 	do_init_fini(tail);
@@ -773,7 +931,7 @@ 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);
@@ -787,13 +945,23 @@ 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->syms, p->hashtab, p->strings);
+	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]->syms,
-			p->deps[i]->hashtab, p->deps[i]->strings);
+		if (p->deps[i]->ghashtab) {
+			if (!gh) gh = gnu_hash(s);
+			sym = gnu_lookup(s, gh, 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;
 	}
@@ -803,7 +971,68 @@ failed:
 	return 0;
 }
 
-void *__dlsym(void *p, const char *s, void *ra)
+int __dladdr(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);
+	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));
+		}
+	}
+
+	for (; nsym; nsym--, sym++) {
+		if (sym->st_shndx && sym->st_value
+		 && (1<<(sym->st_info&0xf) & OK_TYPES)
+		 && (1<<(sym->st_info>>4) & OK_BINDS)) {
+			void *symaddr = p->base + sym->st_value;
+			if (symaddr > addr || symaddr < best)
+				continue;
+			best = symaddr;
+			bestname = strings + sym->st_name;
+			if (addr == symaddr)
+				break;
+		}
+	}
+
+	if (!best) return 0;
+
+	info->dli_fname = p->name;
+	info->dli_fbase = p->base;
+	info->dli_sname = bestname;
+	info->dli_saddr = best;
+
+	return 1;
+}
+
+void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
 {
 	void *res;
 	pthread_rwlock_rdlock(&lock);
@@ -816,7 +1045,11 @@ void *dlopen(const char *file, int mode)
 {
 	return 0;
 }
-void *__dlsym(void *p, const char *s, void *ra)
+void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
+{
+	return 0;
+}
+int __dladdr (void *addr, Dl_info *info)
 {
 	return 0;
 }