aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorAndi Kleen <andi@firstfloor.org>2009-12-08 13:19:42 +0100
committerThomas Gleixner <tglx@linutronix.de>2009-12-08 14:59:36 +0100
commit722d0172377a5697919b9f7e5beb95165b1dec4e (patch)
tree4ee18c7233de8e28b1fc87031fa1be7a2d59e5d2 /kernel
parentf5754bfd107b08edddaf871d676ec6fe0792d07a (diff)
downloadlinux-linaro-722d0172377a5697919b9f7e5beb95165b1dec4e.tar.gz
futex: Take mmap_sem for get_user_pages in fault_in_user_writeable
get_user_pages() must be called with mmap_sem held. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: stable@kernel.org 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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/futex.c10
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;
}