linux-kernel - [PATCH] HWPOISON: Fix page count leak in hwpoison late kill in do_swap

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Message-Id: <1256191352-6903-5-git-send-email-andi@firstfloor.org>
Date:	Thu, 22 Oct 2009 08:02:28 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	linux-kernel@...r.kernel.org
Cc:	fengguang.wu@...el.com, Andi Kleen <ak@...ux.intel.com>
Subject: [PATCH] HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page

From: Andi Kleen <ak@...ux.intel.com>

When returning due to a poisoned page drop the page count.

It wasn't a fatal problem because noone cares about the page count
on a poisoned page (except when it wraps), but it's cleaner to fix it.

Pointed out by Linus.

Signed-off-by: Andi Kleen <ak@...ux.intel.com>
---
 mm/memory.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 7e91b5f..7a3b0ad 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2539,7 +2539,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	} else if (PageHWPoison(page)) {
 		ret = VM_FAULT_HWPOISON;
 		delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
-		goto out;
+		goto out_release;
 	}
 
 	lock_page(page);
@@ -2611,6 +2611,7 @@ out_nomap:
 	pte_unmap_unlock(page_table, ptl);
 out_page:
 	unlock_page(page);
+out_release:
 	page_cache_release(page);
 	return ret;
 }
-- 
1.6.0.2

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