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| author | Andrew Hunter <ahh@google.com> | 2014-01-03 11:22:26 -0800 |
|---|---|---|
| committer | Paul Pluzhnikov <ppluzhnikov@google.com> | 2014-01-03 11:22:26 -0800 |
| commit | 7f507ee17aee720fa423fa38502bc3caa0dd03d7 (patch) | |
| tree | 05ec2f0128d719097d18b531bf5e19c617520649 /nptl/allocatestack.c | |
| parent | 7dd009d8656c0f5c1c633f3764746335a6feefa7 (diff) | |
| download | glibc-7f507ee17aee720fa423fa38502bc3caa0dd03d7.tar.gz glibc-7f507ee17aee720fa423fa38502bc3caa0dd03d7.tar.xz glibc-7f507ee17aee720fa423fa38502bc3caa0dd03d7.zip | |
Async-signal safe TLS.
ChangeLog: 2014-01-03 Andrew Hunter <ahh@google.com> * elf/dl-open.c (): New comment. * elf/dl-reloc.c (_dl_try_allocate_static_tls): Use atomic_compare_and_exchange_bool_acq (_dl_allocate_static_tls): Block signals. * elf/dl-tls.c (allocate_and_init): Return void. (_dl_update_slotinfo): Block signals, use atomic update. nptl/ChangeLog: 2014-01-03 Andrew Hunter <ahh@google.com> * nptl/Makefile (tst-tls7): New test. * nptl/tst-tls7.c: New file. * nptl/tst-tls7mod.c: New file. * nptl/allocatestack.c (init_one_static_tls): Use atomic barrier.
Diffstat (limited to 'nptl/allocatestack.c')
| -rw-r--r-- | nptl/allocatestack.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 7f6094ebb2..2a5ac22117 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -1173,13 +1173,18 @@ init_one_static_tls (struct pthread *curp, struct link_map *map) # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" # endif - /* Fill in the DTV slot so that a later LD/GD access will find it. */ - dtv[map->l_tls_modid].pointer.val = dest; - dtv[map->l_tls_modid].pointer.is_static = true; - /* Initialize the memory. */ memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size), '\0', map->l_tls_blocksize - map->l_tls_initimage_size); + + /* Fill in the DTV slot so that a later LD/GD access will find it. */ + dtv[map->l_tls_modid].pointer.is_static = true; + /* Pairs against the read barrier in tls_get_attr_tail, guaranteeing + any thread waiting for an update to pointer.val sees the + initimage write. */ + atomic_write_barrier (); + dtv[map->l_tls_modid].pointer.val = dest; + } void |