linux-kernel - [PATCH] pagemap: fix order of pmd_trans_unstable() and pmd_trans_huge

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 29 Mar 2012 04:41:41 -0400
From:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Sasha Levin <levinsasha928@...il.com>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Hugh Dickins <hughd@...gle.com>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCH] pagemap: fix order of pmd_trans_unstable() and pmd_trans_huge_lock()

pmd_trans_unstable() in pagemap_pte_range() comes before pmd_trans_huge_lock()
now, which means that pagewalk kicked by reading /proc/pid/pagemap does not
run over thp. This patch fixes it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com>
---
 fs/proc/task_mmu.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git linux-3.3.0-6658a6991ce.orig/fs/proc/task_mmu.c linux-3.3.0-6658a6991ce/fs/proc/task_mmu.c
index 06d2b70..0105ba1 100644
--- linux-3.3.0-6658a6991ce.orig/fs/proc/task_mmu.c
+++ linux-3.3.0-6658a6991ce/fs/proc/task_mmu.c
@@ -781,9 +781,6 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 	int err = 0;
 	pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);
 
-	if (pmd_trans_unstable(pmd))
-		return 0;
-
 	/* find the first VMA at or above 'addr' */
 	vma = find_vma(walk->mm, addr);
 	if (pmd_trans_huge_lock(pmd, vma) == 1) {
@@ -801,6 +798,9 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 		return err;
 	}
 
+	if (pmd_trans_unstable(pmd))
+		return 0;
+
 	for (; addr != end; addr += PAGE_SIZE) {
 
 		/* check to see if we've left 'vma' behind
-- 
1.7.7.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/