diff options
Diffstat (limited to 'elf/dl-tls.c')
| -rw-r--r-- | elf/dl-tls.c | 57 |
1 files changed, 46 insertions, 11 deletions
diff --git a/elf/dl-tls.c b/elf/dl-tls.c index 3d221273f1..3d529b722c 100644 --- a/elf/dl-tls.c +++ b/elf/dl-tls.c @@ -552,9 +552,14 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_modid) /* Allocate initial TLS. RESULT should be a non-NULL pointer to storage for the TLS space. The DTV may be resized, and so this function may call malloc to allocate that space. The loader's GL(dl_load_tls_lock) - is taken when manipulating global TLS-related data in the loader. */ + is taken when manipulating global TLS-related data in the loader. + + If MAIN_THREAD, this is the first call during process + initialization. In this case, TLS initialization for secondary + (audit) namespaces is skipped because that has already been handled + by dlopen. */ void * -_dl_allocate_tls_init (void *result, bool init_tls) +_dl_allocate_tls_init (void *result, bool main_thread) { if (result == NULL) /* The memory allocation failed. */ @@ -627,17 +632,21 @@ _dl_allocate_tls_init (void *result, bool init_tls) some platforms use in static programs requires it. */ dtv[map->l_tls_modid].pointer.val = dest; - /* Copy the initialization image and clear the BSS part. For - audit modules or dependencies with initial-exec TLS, we can not - set the initial TLS image on default loader initialization - because it would already be set by the audit setup. However, - subsequent thread creation would need to follow the default - behaviour. */ - if (map->l_ns != LM_ID_BASE && !init_tls) + /* Copy the initialization image and clear the BSS part. + For audit modules or dependencies with initial-exec TLS, + we can not set the initial TLS image on default loader + initialization because it would already be set by the + audit setup, which uses the dlopen code and already + clears l_need_tls_init. Calls with !main_thread from + pthread_create need to initialze TLS for the current + thread regardless of namespace. */ + if (map->l_ns != LM_ID_BASE && main_thread) continue; memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size), '\0', map->l_tls_blocksize - map->l_tls_initimage_size); + if (main_thread) + map->l_need_tls_init = 0; } total += cnt; @@ -661,7 +670,7 @@ _dl_allocate_tls (void *mem) { return _dl_allocate_tls_init (mem == NULL ? _dl_allocate_tls_storage () - : allocate_dtv (mem), true); + : allocate_dtv (mem), false); } rtld_hidden_def (_dl_allocate_tls) @@ -1094,9 +1103,32 @@ _dl_tls_initial_modid_limit_setup (void) } -void +/* Add module to slot information data. If DO_ADD is false, only the + required memory is allocated. Must be called with + GL (dl_load_tls_lock) acquired. If the function has already been + called for the link map L with !DO_ADD, then this function will not + raise an exception, otherwise it is possible that it encounters a + memory allocation failure. + + Return false if L has already been added to the slotinfo data, or + if L has no TLS data. If the returned value is true, L has been + added with this call (DO_ADD), or has been added in a previous call + (!DO_ADD). + + The expected usage is as follows: Call _dl_add_to_slotinfo for + several link maps with DO_ADD set to false, and record if any calls + result in a true result. If there was a true result, call + _dl_add_to_slotinfo again, this time with DO_ADD set to true. (For + simplicity, it's possible to call the function for link maps where + the previous result was false.) The return value from the second + round of calls can be ignored. If there was true result initially, + call _dl_update_slotinfo to update the TLS generation counter. */ +bool _dl_add_to_slotinfo (struct link_map *l, bool do_add) { + if (l->l_tls_blocksize == 0 || l->l_tls_in_slotinfo) + return false; + /* Now that we know the object is loaded successfully add modules containing TLS data to the dtv info table. We might have to increase its size. */ @@ -1152,7 +1184,10 @@ cannot create TLS data structures")); atomic_store_relaxed (&listp->slotinfo[idx].map, l); atomic_store_relaxed (&listp->slotinfo[idx].gen, GL(dl_tls_generation) + 1); + l->l_tls_in_slotinfo = true; } + + return true; } #if PTHREAD_IN_LIBC |