+#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#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"
static int errflag;
+static char errbuf[128];
-#ifdef __PIC__
-
-#include "reloc.h"
+#ifdef SHARED
#if ULONG_MAX == 0xffffffff
typedef Elf32_Ehdr Ehdr;
#define R_SYM(x) ((x)>>32)
#endif
-struct dso
-{
+#define MAXP2(a,b) (-(-(a)&-(b)))
+#define ALIGN(x,y) ((x)+(y)-1 & -(y))
+
+struct debug {
+ int ver;
+ void *head;
+ void (*bp)(void);
+ int state;
+ void *base;
+};
+
+struct dso {
+ unsigned char *base;
+ char *name;
+ size_t *dynv;
struct dso *next, *prev;
+
+ Phdr *phdr;
+ int phnum;
int refcnt;
- size_t *dynv;
Sym *syms;
uint32_t *hashtab;
+ uint32_t *ghashtab;
char *strings;
- unsigned char *base;
unsigned char *map;
size_t map_len;
dev_t dev;
ino_t ino;
- char global;
+ signed char global;
char relocated;
char constructed;
struct dso **deps;
- char *name;
+ void *tls_image;
+ size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
+ void **new_dtv;
+ unsigned char *new_tls;
+ int new_dtv_idx, new_tls_idx;
+ struct dso *fini_next;
+ char *shortname;
char buf[];
};
-static struct dso *head, *tail, *libc;
+struct symdef {
+ Sym *sym;
+ struct dso *dso;
+};
+
+#include "reloc.h"
+
+void __init_ssp(size_t *);
+void *__install_initial_tls(void *);
+
+static struct dso *head, *tail, *ldso, *fini_head;
static char *env_path, *sys_path, *r_path;
-static int rtld_used;
+static unsigned long long gencnt;
+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 tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
+static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
-#define AUX_CNT 24
+struct debug *_dl_debug_addr = &debug;
+
+#define AUX_CNT 38
#define DYN_CNT 34
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;
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;
return 0;
}
-#define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON)
+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 | 1<<STT_TLS)
#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK)
-static void *find_sym(struct dso *dso, const char *s, int need_def)
+static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
{
- uint32_t h = hash(s);
- void *def = 0;
- if (h==0x6b366be && !strcmp(s, "dlopen")) rtld_used = 1;
- if (h==0x6b3afd && !strcmp(s, "dlsym")) rtld_used = 1;
+ uint32_t h = 0, gh = 0;
+ struct symdef def = {0};
+ 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 (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->st_info>>4 == STB_WEAK) continue;
- def = dso->base + sym->st_value;
- if (sym->st_info>>4 == STB_GLOBAL) break;
+ 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) 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;
}
-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;
- size_t *reloc_addr;
void *ctx;
int type;
int sym_index;
+ struct symdef def;
for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
- reloc_addr = (void *)(base + rel[0]);
type = R_TYPE(rel[1]);
sym_index = R_SYM(rel[1]);
if (sym_index) {
sym = syms + sym_index;
name = strings + sym->st_name;
- ctx = IS_COPY(type) ? dso->next : dso;
- sym_val = (size_t)find_sym(ctx, name, IS_PLT(type));
- if (!sym_val && sym->st_info>>4 != STB_WEAK) {
+ ctx = IS_COPY(type) ? head->next : head;
+ def = find_sym(ctx, name, IS_PLT(type));
+ if (!def.sym && sym->st_info>>4 != STB_WEAK) {
+ snprintf(errbuf, sizeof errbuf,
+ "Error relocating %s: %s: symbol not found",
+ dso->name, name);
if (runtime) longjmp(rtld_fail, 1);
- dprintf(2, "%s: symbol not found\n", name);
- _exit(127);
+ dprintf(2, "%s\n", errbuf);
+ ldso_fail = 1;
+ continue;
}
- sym_size = sym->st_size;
+ } else {
+ sym = 0;
+ def.sym = 0;
+ def.dso = 0;
}
- do_single_reloc(reloc_addr, type, sym_val, sym_size, base, rel[2]);
+ do_single_reloc(dso, base, (void *)(base + rel[0]), type,
+ stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def,
+ def.sym?(size_t)(def.dso->base+def.sym->st_value):0);
}
}
}
}
-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;
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);
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;
+ 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;
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) {
- munmap(map, map_len);
- return 0;
- }
+ if (mmap(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) {
- munmap(map, map_len);
- return 0;
- }
+ 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)
+ goto error;
}
}
for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
- mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC);
+ if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
+ goto error;
break;
}
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);
+ return 0;
}
-static int path_open(const char *name, const char *search)
+static int path_open(const char *name, const char *search, char *buf, size_t buf_size)
{
- char buf[2*NAME_MAX+2];
const char *s=search, *z;
int l, fd;
for (;;) {
if (!*s) return -1;
z = strchr(s, ':');
l = z ? z-s : strlen(s);
- snprintf(buf, sizeof buf, "%.*s/%s", l, s, name);
- if ((fd = open(buf, O_RDONLY))>=0) return fd;
+ snprintf(buf, buf_size, "%.*s/%s", l, s, name);
+ if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
s += l;
}
}
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)
{
- unsigned char *base, *map;
- size_t dyno, map_len;
- struct dso *p;
+ char buf[2*NAME_MAX+2];
+ const char *pathname;
+ unsigned char *map;
+ size_t map_len;
+ struct dso *p, temp_dso = {0};
int fd;
struct stat st;
+ size_t alloc_size;
+ int n_th = 0;
/* Catch and block attempts to reload the implementation itself */
if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
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;
}
}
}
- /* Search for the name to see if it's already loaded */
- for (p=head->next; p; p=p->next) {
- if (!strcmp(p->name, name)) {
- p->refcnt++;
- return p;
- }
- }
if (strchr(name, '/')) {
- fd = open(name, O_RDONLY);
+ pathname = name;
+ 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) {
+ if (p->shortname && !strcmp(p->shortname, name)) {
+ p->refcnt++;
+ return p;
+ }
+ }
if (strlen(name) > NAME_MAX) return 0;
fd = -1;
- if (r_path) fd = path_open(name, r_path);
- if (fd < 0 && env_path) fd = path_open(name, env_path);
+ 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 (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;
+ if (getline(&sys_path, (size_t[1]){0}, f) > 0) {
+ size_t l = strlen(sys_path);
+ if (l && sys_path[l-1]=='\n')
+ sys_path[l-1] = 0;
+ }
fclose(f);
}
}
- if (sys_path) fd = path_open(name, sys_path);
- else fd = path_open(name, "/lib:/usr/local/lib:/usr/lib");
+ if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
+ fd = path_open(name, sys_path, buf, sizeof buf);
}
+ pathname = buf;
}
if (fd < 0) return 0;
if (fstat(fd, &st) < 0) {
}
for (p=head->next; p; p=p->next) {
if (p->dev == st.st_dev && p->ino == st.st_ino) {
+ /* If this library was previously loaded with a
+ * pathname but a search found the same inode,
+ * setup its shortname so it can be found by name. */
+ if (!p->shortname && pathname != name)
+ p->shortname = strrchr(p->name, '/')+1;
close(fd);
p->refcnt++;
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(name) + 1);
+
+ /* Allocate storage for the new DSO. When there is TLS, this
+ * storage must include a reservation for all pre-existing
+ * threads to obtain copies of both the new TLS, and an
+ * extended DTV capable of storing an additional slot for
+ * the newly-loaded DSO. */
+ alloc_size = sizeof *p + strlen(pathname) + 1;
+ 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;
+ if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
+ else alloc_size += n_th * per_th;
+ }
+ p = calloc(1, alloc_size);
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);
-
p->dev = st.st_dev;
p->ino = st.st_ino;
p->refcnt = 1;
p->name = p->buf;
- strcpy(p->name, name);
+ 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()) {
+ free(p);
+ munmap(map, map_len);
+ return 0;
+ }
+ p->tls_id = ++tls_cnt;
+ 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));
+ }
tail->next = p;
p->prev = tail;
tail = p;
+ if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
+
return p;
}
if (p->dynv[i] != DT_NEEDED) continue;
dep = load_library(p->strings + p->dynv[i+1]);
if (!dep) {
- if (runtime) longjmp(rtld_fail, 1);
- dprintf(2, "%s: %m (needed by %s)\n",
+ snprintf(errbuf, sizeof errbuf,
+ "Error loading shared library %s: %m (needed by %s)",
p->strings + p->dynv[i+1], p->name);
- _exit(127);
+ if (runtime) longjmp(rtld_fail, 1);
+ dprintf(2, "%s\n", errbuf);
+ ldso_fail = 1;
+ continue;
}
if (runtime) {
tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
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;
}
}
-static void free_all(struct dso *p)
-{
- struct dso *n;
- while (p) {
- n = p->next;
- if (p->map) free(p);
- p = n;
- }
-}
-
static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
{
for (; cnt--; ph = (void *)((char *)ph + 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_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)
+{
+}
+
+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;
+
+#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;
+ 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);
+ }
+#endif
+ td->dtv = dtv;
+ return td;
+}
+
+void *__tls_get_addr(size_t *v)
+{
+ pthread_t self = __pthread_self();
+ if (self->dtv && v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
+ return (char *)self->dtv[v[0]]+v[1];
+
+ /* Block signals to make accessing new TLS async-signal-safe */
+ sigset_t 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];
+ }
+
+ /* This is safe without any locks held because, if the caller
+ * is able to request the Nth entry of the DTV, the DSO list
+ * must be valid at least that far out and it was synchronized
+ * at program startup or by an already-completed call to dlopen. */
+ struct dso *p;
+ for (p=head; p->tls_id != v[0]; p=p->next);
+
+ /* Get new DTV space from new DSO if needed */
+ if (!self->dtv || v[0] > (size_t)self->dtv[0]) {
+ void **newdtv = p->new_dtv +
+ (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
+ if (self->dtv) memcpy(newdtv, self->dtv,
+ ((size_t)self->dtv[0]+1) * sizeof(void *));
+ newdtv[0] = (void *)v[0];
+ self->dtv = newdtv;
+ }
+
+ /* Get new TLS memory from new DSO */
+ unsigned char *mem = p->new_tls +
+ (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_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 *auxv, aux[AUX_CNT] = {0};
+ size_t aux[AUX_CNT] = {0};
size_t i;
Phdr *phdr;
Ehdr *ehdr;
struct dso *const lib = builtin_dsos+1;
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++)
env_preload = 0;
}
+ /* 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
+ * the start of the page containing the PHDRs; I don't know any
+ * better approach... */
+ if (!aux[AT_BASE]) {
+ aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
+ aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
+ }
+
/* The dynamic linker load address is passed by the kernel
* in the AUX vector, so this is easy. */
lib->base = (void *)aux[AT_BASE];
- lib->name = "libc.so";
+ lib->name = lib->shortname = "libc.so";
lib->global = 1;
ehdr = (void *)lib->base;
- 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);
- /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
- app->base = 0;
- phdr = (void *)aux[AT_PHDR];
- 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);
+ 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. */
+ 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);
+ 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];
+ 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;
+ if (!argv[0]) {
+ dprintf(2, "musl libc/dynamic program loader\n");
+ dprintf(2, "usage: %s pathname%s\n", ldname,
+ ldd_mode ? "" : " [args]");
+ _exit(1);
+ }
+ fd = open(argv[0], O_RDONLY);
+ if (fd < 0) {
+ dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
+ _exit(1);
+ }
+ runtime = 1;
+ ehdr = (void *)map_library(fd, app);
+ if (!ehdr) {
+ dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
+ _exit(1);
+ }
+ runtime = 0;
+ 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 = 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->name = argv[0];
app->global = 1;
app->constructed = 1;
- app->dynv = (void *)(app->base + find_dyn(
- (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
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);
+ 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);
if (phdr->p_type == PT_LOAD)
vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
}
- vdso->name = "linux-gate.so.1";
+ vdso->name = "";
+ vdso->shortname = "linux-gate.so.1";
vdso->global = 1;
decode_dyn(vdso);
vdso->prev = lib;
lib->next = vdso;
- break;
}
/* Initial dso chain consists only of the app. We temporarily
* 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;
if (env_preload) load_preload(env_preload);
load_deps(app);
make_global(app);
+
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))) {
+ dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
+ argv[0], libc.tls_size);
+ _exit(127);
+ }
+ }
+
+ if (ldso_fail) _exit(127);
+ if (ldd_mode) _exit(0);
+
/* Switch to runtime mode: any further failures in the dynamic
* linker are a reportable failure rather than a fatal startup
* error. If the dynamic loader (dlopen) will not be used, free
* all memory used by the dynamic linker. */
runtime = 1;
- do_init_fini(tail);
+#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;
+ debug.base = lib->base;
+ debug.state = 0;
+ _dl_debug_state();
- if (!rtld_used) {
- free_all(head);
- free(sys_path);
- reclaim((void *)builtin_dsos, 0, sizeof builtin_dsos);
- }
+ if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]);
errno = 0;
return (void *)aux[AT_ENTRY];
}
+void __init_ldso_ctors(void)
+{
+ atexit(do_fini);
+ do_init_fini(tail);
+}
+
void *dlopen(const char *file, int mode)
{
- struct dso *volatile p, *orig_tail = tail, *next;
+ struct dso *volatile p, *orig_tail, *next;
+ size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
size_t i;
int cs;
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
pthread_rwlock_wrlock(&lock);
+ __inhibit_ptc();
+
+ p = 0;
+ orig_tls_cnt = tls_cnt;
+ orig_tls_offset = tls_offset;
+ orig_tls_align = tls_align;
+ orig_tail = tail;
if (setjmp(rtld_fail)) {
/* Clean up anything new that was (partially) loaded */
- if (p->deps) for (i=0; p->deps[i]; i++)
+ if (p && p->deps) for (i=0; p->deps[i]; i++)
if (p->deps[i]->global < 0)
p->deps[i]->global = 0;
for (p=orig_tail->next; p; p=next) {
free(p->deps);
free(p);
}
+ tls_cnt = orig_tls_cnt;
+ tls_offset = orig_tls_offset;
+ tls_align = orig_tls_align;
tail = orig_tail;
tail->next = 0;
p = 0;
+ errflag = 1;
+ goto end;
} else p = load_library(file);
if (!p) {
+ snprintf(errbuf, sizeof errbuf,
+ "Error loading shared library %s: %m", file);
errflag = 1;
goto end;
}
p->global = 1;
}
- do_init_fini(tail);
+ update_tls_size();
+
+ if (ssp_used) __init_ssp(libc.auxv);
+
+ _dl_debug_state();
+ 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;
}
+static int invalid_dso_handle(void *h)
+{
+ struct dso *p;
+ for (p=head; p; p=p->next) if (h==p) return 0;
+ snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
+ errflag = 1;
+ return 1;
+}
+
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);
- if (!p) p=head;
- p=p->next;
- }
- if (p == head || p == RTLD_DEFAULT) {
- void *res = find_sym(head, s, 0);
- if (!res) errflag = 1;
- return res;
- }
- h = hash(s);
- sym = lookup(s, h, p->syms, p->hashtab, p->strings);
+ 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);
+ if (!p) p=head;
+ p = p->next;
+ }
+ 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 != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
+ return 0;
+ 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_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++) {
- 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_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;
}
+failed:
errflag = 1;
+ snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
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_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);
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
+static int invalid_dso_handle(void *h)
+{
+ snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
+ errflag = 1;
+ return 1;
+}
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;
}
{
if (!errflag) return 0;
errflag = 0;
- return "unknown error";
+ return errbuf;
}
int dlclose(void *p)
{
- return 0;
+ return invalid_dso_handle(p);
}
projects / musl / blobdiff