From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Peter Feiner , Pavel Emelyanov , Jamie Liu , Hugh Dickins , Andrew Morton , Linus Torvalds , Kamal Mostafa Subject: [PATCH 3.13 146/163] mm: softdirty: keep bit when zapping file pte Date: Thu, 9 Oct 2014 14:02:51 -0700 Message-Id: <1412888588-26755-147-git-send-email-kamal@canonical.com> In-Reply-To: <1412888588-26755-1-git-send-email-kamal@canonical.com> References: <1412888588-26755-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.13.11.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Feiner commit dbab31aa2ceec2d201966fa0b552f151310ba5f4 upstream. This fixes the same bug as b43790eedd31 ("mm: softdirty: don't forget to save file map softdiry bit on unmap") and 9aed8614af5a ("mm/memory.c: don't forget to set softdirty on file mapped fault") where the return value of pte_*mksoft_dirty was being ignored. To be sure that no other pte/pmd "mk" function return values were being ignored, I annotated the functions in arch/x86/include/asm/pgtable.h with __must_check and rebuilt. The userspace effect of this bug is that the softdirty mark might be lost if a file mapped pte get zapped. Signed-off-by: Peter Feiner Acked-by: Cyrill Gorcunov Cc: Pavel Emelyanov Cc: Jamie Liu Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index d411f0d..e3c11e4 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1119,7 +1119,7 @@ again: addr) != page->index) { pte_t ptfile = pgoff_to_pte(page->index); if (pte_soft_dirty(ptent)) - pte_file_mksoft_dirty(ptfile); + ptfile = pte_file_mksoft_dirty(ptfile); set_pte_at(mm, addr, pte, ptfile); } if (PageAnon(page)) -- 1.9.1