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 14:04:15 -0800 |
| commit | bb2fb5d6a16840cf98af1a5d405a583c200d87a8 (patch) | |
| tree | 55d961eb0e70a8dd8ba52a5db698f7934194a02e /kernel/futex.c | |
| parent | f1416ea0278b4bb6629d160e81e61ef8b6bffb4a (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/futex.c')
| -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 fb65e822fc4..d73ef1f3e55 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -304,8 +304,14 @@ 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; } |