aboutsummaryrefslogtreecommitdiff
path: root/elf/dl-tls.c
diff options
context:
space:
mode:
authorAlexandre Oliva <aoliva@redhat.com>2015-03-17 01:14:11 -0300
committerAlexandre Oliva <aoliva@redhat.com>2015-03-17 00:31:49 -0300
commitf8aeae347377f3dfa8cbadde057adf1827fb1d44 (patch)
treecee16d94d0f5b7061455667057da4f141f98b9ae /elf/dl-tls.c
parentb97eb2bdb1ed72982a7821c3078be591051cef59 (diff)
downloadglibc-f8aeae347377f3dfa8cbadde057adf1827fb1d44.zip
glibc-f8aeae347377f3dfa8cbadde057adf1827fb1d44.tar.gz
glibc-f8aeae347377f3dfa8cbadde057adf1827fb1d44.tar.bz2
Fix DTV race, assert, DTV_SURPLUS Static TLS limit, and nptl_db garbage
for ChangeLog [BZ #17090] [BZ #17620] [BZ #17621] [BZ #17628] * NEWS: Update. * elf/dl-tls.c (_dl_update_slotinfo): Clean up outdated DTV entries with Static TLS too. Skip entries past the end of the allocated DTV, from Alan Modra. (tls_get_addr_tail): Update to glibc_likely/unlikely. Move Static TLS DTV entry set up from... (_dl_allocate_tls_init): ... here (fix modid assertion), ... * elf/dl-reloc.c (_dl_nothread_init_static_tls): ... here... * nptl/allocatestack.c (init_one_static_tls): ... and here... * elf/dlopen.c (dl_open_worker): Drop l_tls_modid upper bound for Static TLS. * elf/tlsdeschtab.h (map_generation): Return size_t. Check that the slot we find is associated with the given map before using its generation count. * nptl_db/db_info.c: Include ldsodefs.h. (rtld_global, dtv_slotinfo_list, dtv_slotinfo): New typedefs. * nptl_db/structs.def (DB_RTLD_VARIABLE): New macro. (DB_MAIN_VARIABLE, DB_RTLD_GLOBAL_FIELD): Likewise. (link_map::l_tls_offset): New struct field. (dtv_t::counter): Likewise. (rtld_global): New struct. (_rtld_global): New rtld variable. (dl_tls_dtv_slotinfo_list): New rtld global field. (dtv_slotinfo_list): New struct. (dtv_slotinfo): Likewise. * nptl_db/td_symbol_list.c: Drop gnu/lib-names.h include. (td_lookup): Rename to... (td_mod_lookup): ... this. Use new mod parameter instead of LIBPTHREAD_SO. * nptl_db/td_thr_tlsbase.c: Include link.h. (dtv_slotinfo_list, dtv_slotinfo): New functions. (td_thr_tlsbase): Check DTV generation. Compute Static TLS addresses even if the DTV is out of date or missing them. * nptl_db/fetch-value.c (_td_locate_field): Do not refuse to index zero-length arrays. * nptl_db/thread_dbP.h: Include gnu/lib-names.h. (td_lookup): Make it a macro implemented in terms of... (td_mod_lookup): ... this declaration. * nptl_db/db-symbols.awk (DB_RTLD_VARIABLE): Override. (DB_MAIN_VARIABLE): Likewise.
Diffstat (limited to 'elf/dl-tls.c')
-rw-r--r--elf/dl-tls.c63
1 files changed, 32 insertions, 31 deletions
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
index 9d36d96..20c7e33 100644
--- a/elf/dl-tls.c
+++ b/elf/dl-tls.c
@@ -493,17 +493,14 @@ _dl_allocate_tls_init (void *result)
assert (listp->slotinfo[cnt].gen <= GL(dl_tls_generation));
maxgen = MAX (maxgen, listp->slotinfo[cnt].gen);
+ dtv[map->l_tls_modid].pointer.val = TLS_DTV_UNALLOCATED;
+ dtv[map->l_tls_modid].pointer.is_static = false;
+
if (map->l_tls_offset == NO_TLS_OFFSET
|| map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET)
- {
- /* For dynamically loaded modules we simply store
- the value indicating deferred allocation. */
- dtv[map->l_tls_modid].pointer.val = TLS_DTV_UNALLOCATED;
- dtv[map->l_tls_modid].pointer.is_static = false;
- continue;
- }
+ continue;
- assert (map->l_tls_modid == cnt);
+ assert (map->l_tls_modid == total + cnt);
assert (map->l_tls_blocksize >= map->l_tls_initimage_size);
#if TLS_TCB_AT_TP
assert ((size_t) map->l_tls_offset >= map->l_tls_blocksize);
@@ -515,8 +512,6 @@ _dl_allocate_tls_init (void *result)
#endif
/* Copy the initialization image and clear the BSS part. */
- dtv[map->l_tls_modid].pointer.val = dest;
- dtv[map->l_tls_modid].pointer.is_static = true;
memset (__mempcpy (dest, map->l_tls_initimage,
map->l_tls_initimage_size), '\0',
map->l_tls_blocksize - map->l_tls_initimage_size);
@@ -679,13 +674,16 @@ _dl_update_slotinfo (unsigned long int req_modid)
struct link_map *map = listp->slotinfo[cnt].map;
if (map == NULL)
{
- /* If this modid was used at some point the memory
- might still be allocated. */
- if (! dtv[total + cnt].pointer.is_static
- && dtv[total + cnt].pointer.val != TLS_DTV_UNALLOCATED)
+ if (dtv[-1].counter >= total + cnt)
{
- free (dtv[total + cnt].pointer.val);
+ /* If this modid was used at some point the memory
+ might still be allocated. */
+ if (! dtv[total + cnt].pointer.is_static
+ && (dtv[total + cnt].pointer.val
+ != TLS_DTV_UNALLOCATED))
+ free (dtv[total + cnt].pointer.val);
dtv[total + cnt].pointer.val = TLS_DTV_UNALLOCATED;
+ dtv[total + cnt].pointer.is_static = false;
}
continue;
@@ -718,10 +716,8 @@ _dl_update_slotinfo (unsigned long int req_modid)
memalign and not malloc. */
free (dtv[modid].pointer.val);
- /* This module is loaded dynamically- We defer memory
- allocation. */
- dtv[modid].pointer.is_static = false;
dtv[modid].pointer.val = TLS_DTV_UNALLOCATED;
+ dtv[modid].pointer.is_static = false;
if (modid == req_modid)
the_map = map;
@@ -759,13 +755,12 @@ tls_get_addr_tail (GET_ADDR_ARGS, dtv_t *dtv, struct link_map *the_map)
the_map = listp->slotinfo[idx].map;
}
- again:
/* Make sure that, if a dlopen running in parallel forces the
variable into static storage, we'll wait until the address in the
static TLS block is set up, and use that. If we're undecided
yet, make sure we make the decision holding the lock as well. */
- if (__builtin_expect (the_map->l_tls_offset
- != FORCED_DYNAMIC_TLS_OFFSET, 0))
+ if (__glibc_unlikely (the_map->l_tls_offset
+ != FORCED_DYNAMIC_TLS_OFFSET))
{
__rtld_lock_lock_recursive (GL(dl_load_lock));
if (__glibc_likely (the_map->l_tls_offset == NO_TLS_OFFSET))
@@ -773,22 +768,28 @@ tls_get_addr_tail (GET_ADDR_ARGS, dtv_t *dtv, struct link_map *the_map)
the_map->l_tls_offset = FORCED_DYNAMIC_TLS_OFFSET;
__rtld_lock_unlock_recursive (GL(dl_load_lock));
}
- else
+ else if (__glibc_likely (the_map->l_tls_offset
+ != FORCED_DYNAMIC_TLS_OFFSET))
{
+#if TLS_TCB_AT_TP
+ void *p = (char *) THREAD_SELF - the_map->l_tls_offset;
+#elif TLS_DTV_AT_TP
+ void *p = (char *) THREAD_SELF + the_map->l_tls_offset + TLS_PRE_TCB_SIZE;
+#else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+#endif
__rtld_lock_unlock_recursive (GL(dl_load_lock));
- if (__builtin_expect (the_map->l_tls_offset
- != FORCED_DYNAMIC_TLS_OFFSET, 1))
- {
- void *p = dtv[GET_ADDR_MODULE].pointer.val;
- if (__glibc_unlikely (p == TLS_DTV_UNALLOCATED))
- goto again;
- return (char *) p + GET_ADDR_OFFSET;
- }
+ dtv[GET_ADDR_MODULE].pointer.is_static = true;
+ dtv[GET_ADDR_MODULE].pointer.val = p;
+
+ return (char *) p + GET_ADDR_OFFSET;
}
+ else
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
}
void *p = dtv[GET_ADDR_MODULE].pointer.val = allocate_and_init (the_map);
- dtv[GET_ADDR_MODULE].pointer.is_static = false;
+ assert (!dtv[GET_ADDR_MODULE].pointer.is_static);
return (char *) p + GET_ADDR_OFFSET;
}