summaryrefslogtreecommitdiffstats
path: root/mm
diff options
context:
space:
mode:
authorOleg Nesterov <oleg@redhat.com>2014-10-10 00:27:55 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-10 04:25:56 +0200
commit2c7c3a7d08b28278112f2aaa0b7cf53140101e2a (patch)
tree44e7df021c66b03557afb3a79e1324fa50fbc729 /mm
parentmempolicy: fix show_numa_map() vs exec() + do_set_mempolicy() race (diff)
downloadlinux-2c7c3a7d08b28278112f2aaa0b7cf53140101e2a.tar.xz
linux-2c7c3a7d08b28278112f2aaa0b7cf53140101e2a.zip
mempolicy: kill do_set_mempolicy()->down_write(&mm->mmap_sem)
Remove down_write(&mm->mmap_sem) in do_set_mempolicy(). This logic was never correct and it is no longer needed, see the previous patch. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/mempolicy.c15
1 files changed, 1 insertions, 14 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4378c334e89b..9695a9a3ab90 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -802,7 +802,6 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
nodemask_t *nodes)
{
struct mempolicy *new, *old;
- struct mm_struct *mm = current->mm;
NODEMASK_SCRATCH(scratch);
int ret;
@@ -814,20 +813,11 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
ret = PTR_ERR(new);
goto out;
}
- /*
- * prevent changing our mempolicy while show_numa_maps()
- * is using it.
- * Note: do_set_mempolicy() can be called at init time
- * with no 'mm'.
- */
- if (mm)
- down_write(&mm->mmap_sem);
+
task_lock(current);
ret = mpol_set_nodemask(new, nodes, scratch);
if (ret) {
task_unlock(current);
- if (mm)
- up_write(&mm->mmap_sem);
mpol_put(new);
goto out;
}
@@ -837,9 +827,6 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
nodes_weight(new->v.nodes))
current->il_next = first_node(new->v.nodes);
task_unlock(current);
- if (mm)
- up_write(&mm->mmap_sem);
-
mpol_put(old);
ret = 0;
out: