From: Gerald Schaefer <[email protected]> Subject: mm: don't overwrite mm->def_flags in do_mlockall()
With commit 8e72033 "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 <[email protected]> Reported-by: Vivek Goyal <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> --- mm/mlock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff -puN mm/mlock.c~mm-dont-overwrite-mm-def_flags-in-do_mlockall mm/mlock.c --- a/mm/mlock.c~mm-dont-overwrite-mm-def_flags-in-do_mlockall +++ a/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; _ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
