mm: don't overwrite mm->def_flags in do_mlockall()
authorGerald Schaefer <gerald.schaefer@de.ibm.com>
Tue, 12 Feb 2013 21:46:20 +0000 (13:46 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 17 Feb 2013 18:53:12 +0000 (10:53 -0800)
commit422224746ba5bf508e66b6f4e2cd18ad878a4637
tree52ccb93adebb180e8b2d51395ec1a6ace2e47ab4
parent047b1c0f49ea608e3ca0de2775957f061a0c2737
mm: don't overwrite mm->def_flags in do_mlockall()

commit 9977f0f164d46613288e0b5778eae500dfe06f31 upstream.

With commit 8e72033f2a48 ("thp: make MADV_HUGEPAGE check for
mm->def_flags") the VM_NOHUGEPAGE flag may be set on s390 in
mm->def_flags for certain processes, to prevent future thp mappings.
This would be overwritten by do_mlockall(), which sets it back to 0 with
an optional VM_LOCKED flag set.

To fix this, instead of overwriting mm->def_flags in do_mlockall(), only
the VM_LOCKED flag should be set or cleared.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/mlock.c