From d79df630f622806c4d0e116fbaf6ebf6baf53461 Mon Sep 17 00:00:00 2001
From: David Rientjes <rientjes@google.com>
Date: Fri, 4 Jul 2008 12:24:13 -0700
Subject: [PATCH] mempolicy: mask off internal flags for userspace API
Flags considered internal to the mempolicy kernel code are stored as part
of the "flags" member of struct mempolicy.
Before exposing a policy type to userspace via get_mempolicy(), these
internal flags must be masked. Flags exposed to userspace, however,
should still be returned to the user.
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/mempolicy.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index a37a5034f63dd..c94e58b192c3c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -729,7 +729,11 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
} else {
*policy = pol == &default_policy ? MPOL_DEFAULT :
pol->mode;
- *policy |= pol->flags;
+ /*
+ * Internal mempolicy flags must be masked off before exposing
+ * the policy to userspace.
+ */
+ *policy |= (pol->flags & MPOL_MODE_FLAGS);
}
if (vma) {
--
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