diff options
| author | Cyrill Gorcunov <gorcunov@gmail.com> | 2014-08-06 16:07:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-06 18:01:20 -0700 |
| commit | 9aed8614af5a05cdaa32a0b78b0f1a424754a958 (patch) | |
| tree | e2e790fb6b86e118757b4c9124323b5fcaf6c102 /mm/memory.c | |
| parent | f0093ede9b726ccb1876d43574f5b45c79940aca (diff) | |
| download | lwn-9aed8614af5a05cdaa32a0b78b0f1a424754a958.tar.gz lwn-9aed8614af5a05cdaa32a0b78b0f1a424754a958.zip | |
mm/memory.c: don't forget to set softdirty on file mapped fault
Otherwise we may not notice that pte was softdirty because
pte_mksoft_dirty helper _returns_ new pte but doesn't modify the
argument.
In case if page fault happend on dirty filemapping the newly created pte
may loose softdirty bit thus if a userspace program is tracking memory
changes with help of a memory tracker (CONFIG_MEM_SOFT_DIRTY) it might
miss modification of a memory page (which in worts case may lead to data
inconsistency).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c index 01d0289f30a7..7e131325bdf8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2744,7 +2744,7 @@ void do_set_pte(struct vm_area_struct *vma, unsigned long address, if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); else if (pte_file(*pte) && pte_file_soft_dirty(*pte)) - pte_mksoft_dirty(entry); + entry = pte_mksoft_dirty(entry); if (anon) { inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); |