#include <dlfcn.h>
#include "pthread_impl.h"
#include "libc.h"
-#undef libc
static int errflag;
static char errbuf[128];
#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;
struct dso **deps;
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[];
};
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 int ssp_used;
static int runtime;
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)
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;
}
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;
}
}
}
/* 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) p->shortname = strrchr(p->name, '/')+1;
+ if (!p->shortname && pathname != name)
+ p->shortname = strrchr(p->name, '/')+1;
close(fd);
p->refcnt++;
return p;
map = map_library(fd, &temp_dso);
close(fd);
if (!map) return 0;
- p = malloc(sizeof *p + strlen(pathname) + 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;
}
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;
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;
}
}
-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))
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, size_t cnt)
+void *__copy_tls(unsigned char *mem)
{
+ pthread_t td;
struct dso *p;
+
+ if (!tls_cnt) return mem;
+
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;
+ 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);
}
- ((pthread_t)mem)->dtv = dtv;
- return mem;
+#endif
+ td->dtv = dtv;
+ return td;
}
-void *__tls_get_addr(size_t *p)
+void *__tls_get_addr(size_t *v)
{
pthread_t self = __pthread_self();
- if ((size_t)self->dtv[0] < p[0]) {
- // FIXME: obtain new DTV and TLS from the DSO
- a_crash();
+ 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];
}
- return (char *)self->dtv[p[0]] + p[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)
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;
* 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;
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;
- __libc.tls_cnt = tls_cnt;
+ 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, tls_cnt))) {
+ !__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, tls_cnt);
-
if (ldso_fail) _exit(127);
if (ldd_mode) _exit(0);
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;
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;
p->global = 1;
}
+ update_tls_size();
+
if (ssp_used) __init_ssp(auxv);
_dl_debug_state();
-
- do_init_fini(tail);
+ orig_tail = tail;
end:
+ __release_ptc();
pthread_rwlock_unlock(&lock);
+ if (p) do_init_fini(orig_tail);
pthread_setcancelstate(cs, 0);
return p;
}
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) {
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++) {
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;
}
projects / musl / blobdiff