X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=625f80cca6eb38ca86452713920b2de229ee71a4;hp=3f9bc1451fefa2e4c2dbfb730288f4c443def4c9;hb=2f2f115b58269468304d2f26d029eb470fb44b4a;hpb=5f88c0edd5db0916cbbcdec9042d4986ca778ae8

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 3f9bc145..625f80cc 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -13,13 +13,13 @@
 #include <errno.h>
 #include <limits.h>
 #include <elf.h>
+#include <link.h>
 #include <setjmp.h>
 #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];
@@ -40,6 +40,9 @@ typedef Elf64_Sym Sym;
 #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;
 	void *head;
@@ -54,6 +57,8 @@ struct dso {
 	size_t *dynv;
 	struct dso *next, *prev;
 
+	Phdr *phdr;
+	int phnum;
 	int refcnt;
 	Sym *syms;
 	uint32_t *hashtab;
@@ -72,6 +77,7 @@ struct dso {
 	void **new_dtv;
 	unsigned char *new_tls;
 	int new_dtv_idx, new_tls_idx;
+	struct dso *fini_next;
 	char *shortname;
 	char buf[];
 };
@@ -86,8 +92,9 @@ struct symdef {
 void __init_ssp(size_t *);
 void *__install_initial_tls(void *);
 
-static struct dso *head, *tail, *libc;
+static struct dso *head, *tail, *ldso, *fini_head;
 static char *env_path, *sys_path, *r_path;
+static unsigned long long gencnt;
 static int ssp_used;
 static int runtime;
 static int ldd_mode;
@@ -95,12 +102,12 @@ 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;
+static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
+static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 
 struct debug *_dl_debug_addr = &debug;
 
-#define AUX_CNT 24
+#define AUX_CNT 38
 #define DYN_CNT 34
 
 static void decode_vec(size_t *v, size_t *a, size_t cnt)
@@ -204,14 +211,20 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 			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 && sym->st_info>>4 == STB_WEAK) continue;
-			def.sym = sym;
-			def.dso = dso;
-			if (sym->st_info>>4 == STB_GLOBAL) break;
-		}
+		if (!sym) continue;
+		if (!sym->st_shndx)
+			if (need_def || (sym->st_info&0xf) == STT_TLS)
+				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;
 }
@@ -313,6 +326,8 @@ static void *map_library(int fd, struct dso *dso)
 		eh->e_phoff = sizeof *eh;
 	}
 	ph = (void *)((char *)buf + eh->e_phoff);
+	dso->phdr = ph;
+	dso->phnum = eh->e_phnum;
 	for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 		if (ph->p_type == PT_DYNAMIC)
 			dyn = ph->p_vaddr;
@@ -419,7 +434,7 @@ static struct dso *load_library(const char *name)
 	char buf[2*NAME_MAX+2];
 	const char *pathname;
 	unsigned char *base, *map;
-	size_t dyno, map_len;
+	size_t map_len;
 	struct dso *p, temp_dso = {0};
 	int fd;
 	struct stat st;
@@ -435,12 +450,12 @@ static struct dso *load_library(const char *name)
 			size_t l = z-name;
 			for (rp=reserved; *rp && memcmp(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 (!ldso->prev) {
+					tail->next = ldso;
+					ldso->prev = tail;
+					tail = ldso->next ? ldso->next : ldso;
 				}
-				return libc;
+				return ldso;
 			}
 		}
 	}
@@ -503,7 +518,7 @@ static struct dso *load_library(const char *name)
 	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;
+		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;
 	}
@@ -522,9 +537,23 @@ static struct dso *load_library(const char *name)
 	/* Add a shortname only if name arg was not an explicit pathname. */
 	if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 	if (p->tls_image) {
+		if (runtime && !__pthread_self_init()) {
+			free(p);
+			munmap(map, map_len);
+			return 0;
+		}
 		p->tls_id = ++tls_cnt;
-		tls_size += p->tls_size + p->tls_align + 8*sizeof(size_t) - 1
-			& -4*sizeof(size_t);
+		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));
@@ -608,16 +637,6 @@ static void reloc_all(struct dso *p)
 	}
 }
 
-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;
-	}
-}
-
 static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
 {
 	for (; cnt--; ph = (void *)((char *)ph + stride))
@@ -642,18 +661,37 @@ static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p)
 	p->map_len = max_addr - min_addr;
 }
 
+static void do_fini()
+{
+	struct dso *p;
+	size_t dyn[DYN_CNT] = {0};
+	for (p=fini_head; p; p=p->fini_next) {
+		if (!p->constructed) continue;
+		decode_vec(p->dynv, dyn, DYN_CNT);
+		((void (*)(void))(p->base + dyn[DT_FINI]))();
+	}
+}
+
 static void do_init_fini(struct dso *p)
 {
 	size_t dyn[DYN_CNT] = {0};
+	int need_locking = libc.threads_minus_1;
+	/* Allow recursive calls that arise when a library calls
+	 * dlopen from one of its constructors, but block any
+	 * other threads until all ctors have finished. */
+	if (need_locking) pthread_mutex_lock(&init_fini_lock);
 	for (; p; p=p->prev) {
-		if (p->constructed) return;
+		if (p->constructed) continue;
+		p->constructed = 1;
 		decode_vec(p->dynv, dyn, DYN_CNT);
-		if (dyn[0] & (1<<DT_FINI))
-			atexit((void (*)(void))(p->base + dyn[DT_FINI]));
+		if (dyn[0] & (1<<DT_FINI)) {
+			p->fini_next = fini_head;
+			fini_head = p;
+		}
 		if (dyn[0] & (1<<DT_INIT))
 			((void (*)(void))(p->base + dyn[DT_INIT]))();
-		p->constructed = 1;
 	}
+	if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 }
 
 void _dl_debug_state(void)
@@ -662,21 +700,38 @@ void _dl_debug_state(void)
 
 void *__copy_tls(unsigned char *mem)
 {
+	pthread_t td;
 	struct dso *p;
+
+	if (!tls_cnt) return mem;
+
 	void **dtv = (void *)mem;
 	dtv[0] = (void *)tls_cnt;
-	mem = (void *)(dtv + tls_cnt + 1);
-	for (p=tail; p; p=p->prev) {
+
+#ifdef TLS_ABOVE_TP
+	mem += sizeof(void *) * (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;
-		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;
+		dtv[p->tls_id] = mem + p->tls_offset;
+		memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
+	}
+#else
+	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);
 	}
-	((pthread_t)mem)->dtv = dtv;
-	return mem;
+#endif
+	td->dtv = dtv;
+	return td;
 }
 
 void *__tls_get_addr(size_t *v)
@@ -687,8 +742,7 @@ void *__tls_get_addr(size_t *v)
 
 	/* Block signals to make accessing new TLS async-signal-safe */
 	sigset_t set;
-	sigfillset(&set);
-	pthread_sigmask(SIG_BLOCK, &set, &set);
+	pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
 	if (self->dtv && v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
 		pthread_sigmask(SIG_SETMASK, &set, 0);
 		return (char *)self->dtv[v[0]]+v[1];
@@ -716,11 +770,21 @@ void *__tls_get_addr(size_t *v)
 		(p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1);
 	mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1);
 	self->dtv[v[0]] = mem;
-	memcpy(mem, p->tls_image, p->tls_size);
+	memcpy(mem, p->tls_image, p->tls_len);
 	pthread_sigmask(SIG_SETMASK, &set, 0);
 	return mem + v[1];
 }
 
+static void update_tls_size()
+{
+	libc.tls_size = ALIGN(
+		(1+tls_cnt) * sizeof(void *) +
+		tls_offset +
+		sizeof(struct pthread) +
+		tls_align * 2,
+	tls_align);
+}
+
 void *__dynlink(int argc, char **argv)
 {
 	size_t aux[AUX_CNT] = {0};
@@ -733,6 +797,7 @@ void *__dynlink(int argc, char **argv)
 	struct dso *const vdso = builtin_dsos+2;
 	char *env_preload=0;
 	size_t vdso_base;
+	size_t *auxv;
 
 	/* Find aux vector just past environ[] */
 	for (i=argc+1; argv[i]; i++)
@@ -766,18 +831,19 @@ 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));
+	lib->phnum = ehdr->e_phnum;
+	lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
+	find_map_range(lib->phdr, ehdr->e_phnum, ehdr->e_phentsize, lib);
+	lib->dynv = (void *)(lib->base + find_dyn(lib->phdr,
+                    ehdr->e_phnum, ehdr->e_phentsize));
 	decode_dyn(lib);
 
 	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];
+		app->phdr = phdr = (void *)aux[AT_PHDR];
+		app->phnum = aux[AT_PHNUM];
 		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);
@@ -800,7 +866,7 @@ void *__dynlink(int argc, char **argv)
 	} else {
 		int fd;
 		char *ldname = argv[0];
-		size_t dyno, l = strlen(ldname);
+		size_t l = strlen(ldname);
 		if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
 		*argv++ = (void *)-1;
 		if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
@@ -825,12 +891,23 @@ void *__dynlink(int argc, char **argv)
 		close(fd);
 		lib->name = ldname;
 		app->name = argv[0];
+		app->phnum = ehdr->e_phnum;
+		app->phdr = (void *)(app->base + ehdr->e_phoff);
 		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->tls_id = tls_cnt = 1;
+#ifdef TLS_ABOVE_TP
+		app->tls_offset = 0;
+		tls_offset = app->tls_size
+			+ ( -((uintptr_t)app->tls_image + app->tls_size)
+			& (app->tls_align-1) );
+#else
+		tls_offset = app->tls_offset = app->tls_size
+			+ ( -((uintptr_t)app->tls_image + app->tls_size)
+			& (app->tls_align-1) );
+#endif
+		tls_align = MAXP2(tls_align, app->tls_align);
 	}
 	app->global = 1;
 	app->constructed = 1;
@@ -839,7 +916,8 @@ void *__dynlink(int argc, char **argv)
 	/* 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);
+		vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
+		vdso->phnum = ehdr->e_phnum;
 		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);
@@ -858,7 +936,7 @@ void *__dynlink(int argc, char **argv)
 	 * restore the initial chain in preparation for loading third
 	 * party libraries (preload/needed). */
 	head = tail = app;
-	libc = lib;
+	ldso = lib;
 	app->next = lib;
 	reloc_all(lib);
 	app->next = 0;
@@ -879,36 +957,21 @@ void *__dynlink(int argc, char **argv)
 	load_deps(app);
 	make_global(app);
 
-	/* Make an initial pass setting up TLS before performing relocs.
-	 * This provides the TP-based offset of each DSO's TLS for
-	 * use in TP-relative relocations. After relocations, we need
-	 * to copy the TLS images again in case they had relocs. */
-	tls_size += sizeof(struct pthread) + 4*sizeof(size_t);
-	__libc.tls_size = tls_size;
+	reloc_all(app->next);
+	reloc_all(app);
+
+	update_tls_size();
 	if (tls_cnt) {
-		struct dso *p;
-		void *mem = mmap(0, __libc.tls_size, PROT_READ|PROT_WRITE,
+		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))) {
 			dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
-				argv[0], tls_size);
+				argv[0], libc.tls_size);
 			_exit(127);
 		}
-		for (p=head; p; p=p->next) {
-			if (!p->tls_id) continue;
-			p->tls_offset = (char *)__pthread_self()
-				- (char *)__pthread_self()->dtv[p->tls_id];
-		}
 	}
 
-	reloc_all(app->next);
-	reloc_all(app);
-
-	/* The initial DTV is located at the base of the memory
-	 * allocated for TLS. Repeat copying TLS to pick up relocs. */
-	if (tls_cnt) __copy_tls((void *)__pthread_self()->dtv);
-
 	if (ldso_fail) _exit(127);
 	if (ldd_mode) _exit(0);
 
@@ -930,8 +993,9 @@ void *__dynlink(int argc, char **argv)
 	debug.state = 0;
 	_dl_debug_state();
 
-	if (ssp_used) __init_ssp(auxv);
+	if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]);
 
+	atexit(do_fini);
 	do_init_fini(tail);
 
 	errno = 0;
@@ -941,7 +1005,7 @@ void *__dynlink(int argc, char **argv)
 void *dlopen(const char *file, int mode)
 {
 	struct dso *volatile p, *orig_tail, *next;
-	size_t orig_tls_cnt;
+	size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
 	size_t i;
 	int cs;
 
@@ -953,6 +1017,8 @@ void *dlopen(const char *file, int mode)
 
 	p = 0;
 	orig_tls_cnt = tls_cnt;
+	orig_tls_offset = tls_offset;
+	orig_tls_align = tls_align;
 	orig_tail = tail;
 
 	if (setjmp(rtld_fail)) {
@@ -967,7 +1033,8 @@ void *dlopen(const char *file, int mode)
 			free(p);
 		}
 		tls_cnt = orig_tls_cnt;
-		tls_size = __libc.tls_size;
+		tls_offset = orig_tls_offset;
+		tls_align = orig_tls_align;
 		tail = orig_tail;
 		tail->next = 0;
 		p = 0;
@@ -1002,16 +1069,17 @@ void *dlopen(const char *file, int mode)
 		p->global = 1;
 	}
 
-	__libc.tls_size = tls_size;
+	update_tls_size();
 
-	if (ssp_used) __init_ssp(auxv);
+	if (ssp_used) __init_ssp(libc.auxv);
 
 	_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;
 }
@@ -1022,12 +1090,17 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra)
 	uint32_t h = 0, gh = 0;
 	Sym *sym;
 	if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
-		if (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);
 			if (!p) p=head;
+			p = p->next;
 		}
-		struct symdef def = find_sym(p->next, s, 0);
+		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});
 		return def.dso->base + def.sym->st_value;
 	}
 	if (p->ghashtab) {
@@ -1037,6 +1110,8 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra)
 		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 (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++) {
@@ -1047,6 +1122,8 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra)
 			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 (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
 			return p->deps[i]->base + sym->st_value;
 	}
@@ -1125,6 +1202,32 @@ void *__dlsym(void *restrict p, const char *restrict s, void *restrict 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
 void *dlopen(const char *file, int mode)
 {