Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 03/10] mm: dont overwrite mm->def_flags in do_mlockall() | Date | Fri, 15 Feb 2013 14:56:35 -0800 |
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3.7-stable review patch. If anyone has any objections, please let me know.
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From: Gerald Schaefer <gerald.schaefer@de.ibm.com>
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 | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/mm/mlock.c +++ b/mm/mlock.c @@ -517,11 +517,11 @@ SYSCALL_DEFINE2(munlock, unsigned long, static int do_mlockall(int flags) { struct vm_area_struct * vma, * prev = NULL; - unsigned int def_flags = 0; if (flags & MCL_FUTURE) - def_flags = VM_LOCKED; - current->mm->def_flags = def_flags; + current->mm->def_flags |= VM_LOCKED; + else + current->mm->def_flags &= ~VM_LOCKED; if (flags == MCL_FUTURE) goto out;
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