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| 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/sysdeps | |
| parent | 01f1f5ee8b58d5a3dce5250ed3514e9dfa5ceff4 (diff) | |
| download | glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.tar glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.tar.gz glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.tar.bz2 glibc-66f1b8eeb20c49c8566abeeacf36540f258ad5f4.zip | |
Fix setxid race with thread creation
Diffstat (limited to 'nptl/sysdeps')
| -rw-r--r-- | nptl/sysdeps/pthread/createthread.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/nptl/sysdeps/pthread/createthread.c b/nptl/sysdeps/pthread/createthread.c index 66fafe8050..3bb3915281 100644 --- a/nptl/sysdeps/pthread/createthread.c +++ b/nptl/sysdeps/pthread/createthread.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002-2007, 2008 Free Software Foundation, Inc. +/* Copyright (C) 2002-2007, 2008, 2010 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. @@ -28,7 +28,7 @@ #include "kernel-features.h" -#define CLONE_SIGNAL (CLONE_SIGHAND | CLONE_THREAD) +#define CLONE_SIGNAL (CLONE_SIGHAND | CLONE_THREAD) /* Unless otherwise specified, the thread "register" is going to be initialized with a pointer to the TCB. */ @@ -72,8 +72,14 @@ do_clone (struct pthread *pd, const struct pthread_attr *attr, that cares whether the thread count is correct. */ atomic_increment (&__nptl_nthreads); - if (ARCH_CLONE (fct, STACK_VARIABLES_ARGS, clone_flags, - pd, &pd->tid, TLS_VALUE, &pd->tid) == -1) + int rc = ARCH_CLONE (fct, STACK_VARIABLES_ARGS, clone_flags, + pd, &pd->tid, TLS_VALUE, &pd->tid); + + /* Allow setxid from now onwards. */ + if (__builtin_expect (atomic_exchange_acq (&pd->setxid_futex, 0) == -2, 0)) + lll_futex_wake (&pd->setxid_futex, 1, LLL_PRIVATE); + + if (__builtin_expect (rc == -1, 0)) { atomic_decrement (&__nptl_nthreads); /* Oops, we lied for a second. */ |