diff options
| author | Ulrich Drepper <drepper@redhat.com> | 2010-03-05 11:23:28 -0800 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2010-03-05 11:23:28 -0800 |
| commit | 66f1b8eeb20c49c8566abeeacf36540f258ad5f4 (patch) | |
| tree | 1149fbc80470ff586f1815d334b5308ad24cc4cb /nptl/allocatestack.c | |
| parent | 01f1f5ee8b58d5a3dce5250ed3514e9dfa5ceff4 (diff) | |
| download | glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.tar.gz glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.tar.xz glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.zip | |
Fix setxid race with thread creation
Diffstat (limited to 'nptl/allocatestack.c')
| -rw-r--r-- | nptl/allocatestack.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 3c3585fe37..899c0e8eee 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002-2007, 2009 Free Software Foundation, Inc. +/* Copyright (C) 2002-2007, 2009, 2010 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. @@ -380,7 +380,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, - TLS_TCB_SIZE - adj); #elif TLS_DTV_AT_TP pd = (struct pthread *) (((uintptr_t) attr->stackaddr - - __static_tls_size - adj) + - __static_tls_size - adj) - TLS_PRE_TCB_SIZE); #endif @@ -546,7 +546,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, #ifndef __ASSUME_PRIVATE_FUTEX /* The thread must know when private futexes are supported. */ pd->header.private_futex = THREAD_GETMEM (THREAD_SELF, - header.private_futex); + header.private_futex); #endif #ifdef NEED_DL_SYSINFO @@ -969,6 +969,13 @@ setxid_mark_thread (struct xid_command *cmdp, struct pthread *t) { int ch; + /* Wait until this thread is cloned. */ + if (t->setxid_futex == -1 + && ! atomic_compare_and_exchange_bool_acq (&t->setxid_futex, -2, -1)) + do + lll_futex_wait (&t->setxid_futex, -2, LLL_PRIVATE); + while (t->setxid_futex == -2); + /* Don't let the thread exit before the setxid handler runs. */ t->setxid_futex = 0; |