diff options
| author | Andi Kleen <andi@firstfloor.org> | 2009-12-08 13:19:42 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-12-18 13:43:21 -0800 |
| commit | 7098a7420bc7c75253d785119d91be6ab15e18e5 (patch) | |
| tree | 31a56e011400fae66ca7ab9a03706d3f25e1ac93 /kernel | |
| parent | 1f5c6cef516b8ff4d5fe5f6976a5aad5b4ee9c06 (diff) | |
futex: Take mmap_sem for get_user_pages in fault_in_user_writeable
commit 722d0172377a5697919b9f7e5beb95165b1dec4e upstream.
get_user_pages() must be called with mmap_sem held.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Darren Hart <dvhltc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091208121942.GA21298@basil.fritz.box>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/futex.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index c0a020fcc246..ba7f0be17531 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -303,8 +303,14 @@ void put_futex_key(int fshared, union futex_key *key) */ static int fault_in_user_writeable(u32 __user *uaddr) { - int ret = get_user_pages(current, current->mm, (unsigned long)uaddr, - 1, 1, 0, NULL, NULL); + struct mm_struct *mm = current->mm; + int ret; + + down_read(&mm->mmap_sem); + ret = get_user_pages(current, mm, (unsigned long)uaddr, + 1, 1, 0, NULL, NULL); + up_read(&mm->mmap_sem); + return ret < 0 ? ret : 0; } |