diff options
| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2015-05-11 17:52:14 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 08:39:16 +0200 |
| commit | d9b9ff8c18891d74dc7076800bde81b774f7d032 (patch) | |
| tree | ce12138209e397d4fcbb1339990741dca7f2bfc9 /include/asm-generic | |
| parent | f3dae07e442a8131a5485b6a38db2aa22a7a48cf (diff) | |
sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly
Let's explicitly disable/enable preemption in the !CONFIG_SMP version
of futex_atomic_cmpxchg_inatomic(), to prepare for pagefault_disable() not
touching preemption anymore. This is needed for this function to be
callable from both, atomic and non-atomic context.
Otherwise we might break mutual exclusion when relying on a get_user()/
put_user() implementation.
Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-10-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/futex.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index 358601750fe7..e56272c919b5 100644 --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -107,6 +107,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, { u32 val; + preempt_disable(); if (unlikely(get_user(val, uaddr) != 0)) return -EFAULT; @@ -114,6 +115,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, return -EFAULT; *uval = val; + preempt_enable(); return 0; } |