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| author | Andrea Arcangeli <aarcange@redhat.com> | 2020-04-07 06:05:33 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-07 20:43:39 +0300 |
| commit | 5a281062af1d43d3f3956a6b429c2d727bc92603 (patch) | |
| tree | 8c4c2c81d3e0c66fa7208dd9e1862a2a74df1945 /init | |
| parent | 529b930b87d997c3d231c9d8638a0bf8db569d70 (diff) | |
| download | linux-5a281062af1d43d3f3956a6b429c2d727bc92603.tar.xz | |
userfaultfd: wp: add WP pagetable tracking to x86
Accurate userfaultfd WP tracking is possible by tracking exactly which
virtual memory ranges were writeprotected by userland. We can't relay
only on the RW bit of the mapped pagetable because that information is
destroyed by fork() or KSM or swap. If we were to relay on that, we'd
need to stay on the safe side and generate false positive wp faults for
every swapped out page.
[peterx@redhat.com: append _PAGE_UFD_WP to _PAGE_CHG_MASK]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-4-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index 1c12059e0f7e..2bc0e47689d8 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1556,6 +1556,11 @@ config ADVISE_SYSCALLS applications use these syscalls, you can disable this option to save space. +config HAVE_ARCH_USERFAULTFD_WP + bool + help + Arch has userfaultfd write protection support + config MEMBARRIER bool "Enable membarrier() system call" if EXPERT default y |