X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=de0f2ac876ab763ff236f5a0d2ef75311fd7549c;hb=e13a2b8953ef;hp=f4c32ffea52828b8095439c343bc92ab47d446eb;hpb=e152ee9778846c1f233641b2d3562ccdb081c6a9;p=musl

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index f4c32ffe..de0f2ac8 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -7,12 +7,9 @@
 #include <elf.h>
 #include <sys/mman.h>
 #include <limits.h>
-#include <stdint.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <errno.h>
-#include <limits.h>
-#include <elf.h>
 #include <link.h>
 #include <setjmp.h>
 #include <pthread.h>
@@ -63,6 +60,7 @@ struct dso {
 	Sym *syms;
 	uint32_t *hashtab;
 	uint32_t *ghashtab;
+	int16_t *versym;
 	char *strings;
 	unsigned char *map;
 	size_t map_len;
@@ -71,9 +69,12 @@ 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;
 	int new_dtv_idx, new_tls_idx;
@@ -90,11 +91,13 @@ struct symdef {
 #include "reloc.h"
 
 void __init_ssp(size_t *);
-void *__install_initial_tls(void *);
+int __init_tp(void *);
 void __init_libc(char **, char *);
 
+const char *__libc_get_version(void);
+
 static struct dso *head, *tail, *ldso, *fini_head;
-static char *env_path, *sys_path, *r_path;
+static char *env_path, *sys_path;
 static unsigned long long gencnt;
 static int ssp_used;
 static int runtime;
@@ -106,6 +109,7 @@ static pthread_rwlock_t lock;
 static struct debug debug;
 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 };
+static long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)];
 
 struct debug *_dl_debug_addr = &debug;
 
@@ -156,7 +160,8 @@ static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 	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))
+		if ((!dso->versym || dso->versym[i] >= 0)
+		    && (!strcmp(s, strings+syms[i].st_name)))
 			return syms+i;
 	}
 	return 0;
@@ -164,25 +169,24 @@ static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 
 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 {
-	Sym *sym;
-	char *strings;
+	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 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]);
+	hashval = buckets + nbuckets + (i - hashtab[1]);
 
-	for (h1 |= 1; ; sym++) {
+	for (h1 |= 1; ; i++) {
 		h2 = *hashval++;
-		if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name))
-			return sym;
+		if ((!dso->versym || dso->versym[i] >= 0)
+		    && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
+			return syms+i;
 		if (h2 & 1) break;
 	}
 
@@ -251,7 +255,8 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
 			name = strings + sym->st_name;
 			ctx = IS_COPY(type) ? head->next : head;
 			def = find_sym(ctx, name, IS_PLT(type));
-			if (!def.sym && sym->st_info>>4 != STB_WEAK) {
+			if (!def.sym && (sym->st_shndx != SHN_UNDEF
+			    || sym->st_info>>4 != STB_WEAK)) {
 				snprintf(errbuf, sizeof errbuf,
 					"Error relocating %s: %s: symbol not found",
 					dso->name, name);
@@ -277,27 +282,29 @@ 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 = (size_t *)(dso->base + start);
+	z = (size_t *)(dso->base + 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, Phdr *ph, size_t phent, size_t phcnt)
 {
 	for (; phcnt--; ph=(void *)((char *)ph+phent)) {
 		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);
 	}
 }
@@ -305,6 +312,7 @@ static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phc
 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;
@@ -312,19 +320,28 @@ static void *map_library(int fd, struct dso *dso)
 	Ehdr *eh;
 	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 (l<sizeof *eh) return 0;
 	eh = buf;
+	if (l<0) return 0;
+	if (l<sizeof *eh || (eh->e_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;
+		if (l < 0) goto error;
+		if (l != phsize) goto noexec;
 		ph = ph0 = (void *)(buf + 1);
 	} else {
 		ph = ph0 = (void *)((char *)buf + eh->e_phoff);
@@ -332,11 +349,14 @@ static void *map_library(int fd, struct dso *dso)
 	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) {
+		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;
 		if (ph->p_vaddr < addr_min) {
@@ -350,7 +370,7 @@ static void *map_library(int fd, struct dso *dso)
 			addr_max = ph->p_vaddr+ph->p_memsz;
 		}
 	}
-	if (!dyn) return 0;
+	if (!dyn) goto noexec;
 	addr_max += PAGE_SIZE-1;
 	addr_max &= -PAGE_SIZE;
 	addr_min &= -PAGE_SIZE;
@@ -361,7 +381,13 @@ static void *map_library(int fd, struct dso *dso)
 	 * 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;
+	/* 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;
 	dso->phdr = 0;
 	dso->phnum = 0;
@@ -399,15 +425,19 @@ static void *map_library(int fd, struct dso *dso)
 				goto error;
 			break;
 		}
-	if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum);
 	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);
+	if (!runtime) reclaim_gaps(dso, ph0, eh->e_phentsize, eh->e_phnum);
+	free(allocated_buf);
 	return map;
+noexec:
+	errno = ENOEXEC;
 error:
-	munmap(map, map_len);
+	if (map!=MAP_FAILED) munmap(map, map_len);
+	free(allocated_buf);
 	return 0;
 }
 
@@ -426,6 +456,64 @@ static int path_open(const char *name, const char *s, char *buf, size_t buf_size
 	}
 }
 
+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) return 0;
+	if (!p->rpath_orig) return -1;
+	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 -1;
+		s = t+1;
+		n++;
+	}
+	if (n > SSIZE_MAX/PATH_MAX) return -1;
+
+	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, $ORIGIN can be processed safely
+		 * since the library's pathname came from a trusted source
+		 * (either system paths or a call to dlopen). */
+		if (libc.secure)
+			return -1;
+		l = readlink("/proc/self/exe", buf, buf_size);
+		if (l >= buf_size)
+			return -1;
+		buf[l] = 0;
+		origin = buf;
+	} else {
+		origin = p->name;
+	}
+	t = strrchr(origin, '/');
+	l = t ? t-origin : 0;
+	p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
+	if (!p->rpath) return -1;
+
+	d = p->rpath;
+	s = p->rpath_orig;
+	while ((t=strchr(s, '$'))) {
+		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};
@@ -434,11 +522,15 @@ static void decode_dyn(struct dso *p)
 	p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 	if (dyn[0]&(1<<DT_HASH))
 		p->hashtab = (void *)(p->base + dyn[DT_HASH]);
+	if (dyn[0]&(1<<DT_RPATH))
+		p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
 	if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 		p->ghashtab = (void *)(p->base + *dyn);
+	if (search_vec(p->dynv, dyn, DT_VERSYM))
+		p->versym = (void *)(p->base + *dyn);
 }
 
-static struct dso *load_library(const char *name)
+static struct dso *load_library(const char *name, struct dso *needed_by)
 {
 	char buf[2*NAME_MAX+2];
 	const char *pathname;
@@ -448,6 +540,7 @@ static struct dso *load_library(const char *name)
 	struct stat st;
 	size_t alloc_size;
 	int n_th = 0;
+	int is_self = 0;
 
 	/* Catch and block attempts to reload the implementation itself */
 	if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
@@ -456,17 +549,33 @@ 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 (!ldso->prev) {
-					tail->next = ldso;
-					ldso->prev = tail;
-					tail = ldso->next ? ldso->next : ldso;
+				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 ldso;
+				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|O_CLOEXEC);
@@ -480,8 +589,10 @@ 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 (env_path) fd = path_open(name, env_path, buf, sizeof buf);
+		for (p=needed_by; fd < 0 && p; p=p->needed_by)
+			if (!fixup_rpath(p, buf, sizeof buf))
+				fd = path_open(name, p->rpath, buf, sizeof buf);
 		if (fd < 0) {
 			if (!sys_path) {
 				char *prefix = 0;
@@ -510,6 +621,8 @@ static struct dso *load_library(const char *name)
 						sys_path = "";
 					}
 					fclose(f);
+				} else if (errno != ENOENT) {
+					sys_path = "";
 				}
 			}
 			if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
@@ -561,14 +674,16 @@ static struct dso *load_library(const char *name)
 	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) {
-		if (runtime && !__pthread_self_init()) {
+		if (runtime && !libc.has_thread_pointer) {
 			munmap(map, p->map_len);
 			free(p);
+			errno = ENOSYS;
 			return 0;
 		}
 		p->tls_id = ++tls_cnt;
@@ -602,13 +717,9 @@ 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)",
@@ -626,7 +737,6 @@ static void load_deps(struct dso *p)
 				*deps = tmp;
 			}
 		}
-		r_path = 0;
 	}
 }
 
@@ -639,7 +749,7 @@ static void load_preload(char *s)
 		for (z=s; *z && !isspace(*z); z++);
 		tmp = *z;
 		*z = 0;
-		load_library(s);
+		load_library(s, 0);
 		*z = tmp;
 	}
 }
@@ -662,6 +772,17 @@ static void reloc_all(struct dso *p)
 			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);
+
+		if (p->relro_start != p->relro_end &&
+		    mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
+			snprintf(errbuf, sizeof errbuf,
+				"Error relocating %s: RELRO protection failed",
+				p->name);
+			if (runtime) longjmp(*rtld_fail, 1);
+			dprintf(2, "%s\n", errbuf);
+			ldso_fail = 1;
+		}
+
 		p->relocated = 1;
 	}
 }
@@ -678,6 +799,10 @@ 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_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;
@@ -703,7 +828,7 @@ static void do_fini()
 			while (n--) ((void (*)(void))*--fn)();
 		}
 #ifndef NO_LEGACY_INITFINI
-		if (dyn[0] & (1<<DT_FINI))
+		if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 			((void (*)(void))(p->base + dyn[DT_FINI]))();
 #endif
 	}
@@ -726,7 +851,7 @@ static void do_init_fini(struct dso *p)
 			fini_head = p;
 		}
 #ifndef NO_LEGACY_INITFINI
-		if (dyn[0] & (1<<DT_INIT))
+		if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 			((void (*)(void))(p->base + dyn[DT_INIT]))();
 #endif
 		if (dyn[0] & (1<<DT_INIT_ARRAY)) {
@@ -746,15 +871,31 @@ void _dl_debug_state(void)
 {
 }
 
+void __reset_tls()
+{
+	pthread_t self = __pthread_self();
+	struct dso *p;
+	for (p=head; p; p=p->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 *__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;
+	if (!tls_cnt) {
+		td = (void *)(dtv+1);
+		td->dtv = dtv;
+		return td;
+	}
 
 #ifdef TLS_ABOVE_TP
 	mem += sizeof(void *) * (tls_cnt+1);
@@ -847,6 +988,7 @@ void *__dynlink(int argc, char **argv)
 	size_t vdso_base;
 	size_t *auxv;
 	char **envp = argv+argc+1;
+	void *initial_tls;
 
 	/* Find aux vector just past environ[] */
 	for (i=argc+1; argv[i]; i++)
@@ -863,7 +1005,9 @@ void *__dynlink(int argc, char **argv)
 	  || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
 		env_path = 0;
 		env_preload = 0;
+		libc.secure = 1;
 	}
+	libc.page_size = aux[AT_PAGESZ];
 
 	/* 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
@@ -879,12 +1023,13 @@ void *__dynlink(int argc, char **argv)
 	lib->base = (void *)aux[AT_BASE];
 	lib->name = lib->shortname = "libc.so";
 	lib->global = 1;
+	lib->kernel_mapped = 1;
 	ehdr = (void *)lib->base;
 	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));
+		ehdr->e_phnum, ehdr->e_phentsize));
 	decode_dyn(lib);
 
 	if (aux[AT_PHDR]) {
@@ -907,7 +1052,12 @@ void *__dynlink(int argc, char **argv)
 		}
 		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];
+		if ((aux[0] & (1UL<<AT_EXECFN))
+		    && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
+			app->name = (char *)aux[AT_EXECFN];
+		else
+			app->name = argv[0];
+		app->kernel_mapped = 1;
 		app->dynv = (void *)(app->base + find_dyn(
 			(void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
 		find_map_range((void *)aux[AT_PHDR],
@@ -920,8 +1070,11 @@ void *__dynlink(int argc, char **argv)
 		*argv++ = (void *)-1;
 		if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
 		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 [--] pathname%s\n",
+				__libc_get_version(), ldname,
 				ldd_mode ? "" : " [args]");
 			_exit(1);
 		}
@@ -940,9 +1093,17 @@ 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;
+		aux[AT_ENTRY] = (size_t)app->base + 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; i<app->phnum; i++) {
+				if (app->phdr[i].p_type == PT_INTERP)
+					lib->name = (void *)(app->base
+						+ app->phdr[i].p_vaddr);
+			}
+			dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
+		}
 	}
 	if (app->tls_size) {
 		app->tls_id = tls_cnt = 1;
@@ -993,9 +1154,9 @@ void *__dynlink(int argc, char **argv)
 	/* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
 
 	/* Donate unused parts of app and library mapping to malloc */
-	reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
+	reclaim_gaps(app, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
 	ehdr = (void *)lib->base;
-	reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
+	reclaim_gaps(lib, (void *)(lib->base+ehdr->e_phoff),
 		ehdr->e_phentsize, ehdr->e_phnum);
 
 	/* Load preload/needed libraries, add their symbols to the global
@@ -1006,19 +1167,29 @@ void *__dynlink(int argc, char **argv)
 	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
+
 	reloc_all(app->next);
 	reloc_all(app);
 
 	update_tls_size();
-	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))) {
+	if (libc.tls_size > sizeof builtin_tls) {
+		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);
 		}
+	} else {
+		initial_tls = builtin_tls;
+	}
+	if (__init_tp(__copy_tls(initial_tls)) < 0 && tls_cnt) {
+		dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]);
+		_exit(127);
 	}
 
 	if (ldso_fail) _exit(127);
@@ -1030,11 +1201,6 @@ 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;
@@ -1092,7 +1258,7 @@ void *dlopen(const char *file, int mode)
 		p = 0;
 		errflag = 1;
 		goto end;
-	} else p = load_library(file);
+	} else p = load_library(file, head);
 
 	if (!p) {
 		snprintf(errbuf, sizeof errbuf, noload ?
@@ -1198,7 +1364,7 @@ failed:
 	return 0;
 }
 
-int __dladdr(void *addr, Dl_info *info)
+int __dladdr(const void *addr, Dl_info *info)
 {
 	struct dso *p;
 	Sym *sym;
@@ -1223,7 +1389,7 @@ int __dladdr(void *addr, Dl_info *info)
 		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++) {
+		for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 			if (buckets[i] > nsym)
 				nsym = buckets[i];
 		}
@@ -1308,7 +1474,7 @@ void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
 {
 	return 0;
 }
-int __dladdr (void *addr, Dl_info *info)
+int __dladdr (const void *addr, Dl_info *info)
 {
 	return 0;
 }