linux-kernel - [patch] mm: memcontrol: rewrite uncharge API fix

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>] [day] [month] [year] [list]

Date:	Mon, 28 Jul 2014 13:10:23 -0400
From:	Johannes Weiner <hannes@...xchg.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Michal Hocko <mhocko@...e.cz>, Hugh Dickins <hughd@...gle.com>,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: [patch] mm: memcontrol: rewrite uncharge API fix - clear page->mapping in migration

The page->mapping reset in migration was conditionalized so that a
later uncharge could use PageAnon() to figure out the page type.  But
after "mm: memcontrol: rewrite uncharge API fix - double migration",
the old page is uncharged directly in mem_cgroup_migrate() and so this
is no longer necessary.

Once all fixups are folded into the "rewrite uncharge API" patch,
there will be no reason and no explanation for this change anymore, so
revert it.

Signed-off-by: Johannes Weiner <hannes@...xchg.org>
---
 mm/migrate.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 7f5a42403fae..5a46f1ec5f43 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -778,14 +778,12 @@ static int move_to_new_page(struct page *newpage, struct page *page,
 		rc = fallback_migrate_page(mapping, newpage, page, mode);
 
 	if (rc != MIGRATEPAGE_SUCCESS) {
-		if (!PageAnon(newpage))
-			newpage->mapping = NULL;
+		newpage->mapping = NULL;
 	} else {
 		mem_cgroup_migrate(page, newpage, false);
 		if (remap_swapcache)
 			remove_migration_ptes(page, newpage);
-		if (!PageAnon(page))
-			page->mapping = NULL;
+		page->mapping = NULL;
 	}
 
 	unlock_page(newpage);
-- 
2.0.0

--
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/