From patchwork Fri Feb 15 17:03:10 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3.5.y.z, extended, stable] Patch "mm: don't overwrite mm->def_flags in do_mlockall()" has been added to staging queue Date: Fri, 15 Feb 2013 07:03:10 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 221143 Message-Id: <1360947790-25345-1-git-send-email-herton.krzesinski@canonical.com> To: Gerald Schaefer Cc: Andrea Arcangeli , Hugh Dickins , Heiko Carstens , kernel-team@lists.ubuntu.com, Martin Schwidefsky , Andrew Morton , Linus Torvalds , Vivek Goyal This is a note to let you know that I have just added a patch titled mm: don't overwrite mm->def_flags in do_mlockall() to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ >From 2b6fa114faf2d17d0e8a72be3c486d64559aa4fd Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Tue, 12 Feb 2013 13:46:20 -0800 Subject: [PATCH] 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 Reported-by: Vivek Goyal Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Herton Ronaldo Krzesinski --- mm/mlock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) -- 1.7.9.5 diff --git a/mm/mlock.c b/mm/mlock.c index ef726e8..3283272 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -524,11 +524,11 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) 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;