From: Wu Fengguang <fengguang.wu@intel.com>
Date: Mon, 19 Oct 2009 06:15:01 +0000 (+0200)
Subject: HWPOISON: fix invalid page count in printk output
X-Git-Tag: firefly_0821_release~12027^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7456b0405d8fc063c49628f969cdb23be060fc80;p=firefly-linux-kernel-4.4.55.git

HWPOISON: fix invalid page count in printk output

The madvise injector already holds a reference when passing in a page
to the memory-failure code. The code corrects for this additional reference
for its checks, but the final printk output didn't. Fix that.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e354b9f2f389..dacc64183874 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -613,13 +613,16 @@ static int page_action(struct page_state *ps, struct page *p,
 			unsigned long pfn, int ref)
 {
 	int result;
+	int count;
 
 	result = ps->action(p, pfn);
 	action_result(pfn, ps->msg, result);
-	if (page_count(p) != 1 + ref)
+
+	count = page_count(p) - 1 - ref;
+	if (count != 0)
 		printk(KERN_ERR
 		       "MCE %#lx: %s page still referenced by %d users\n",
-		       pfn, ps->msg, page_count(p) - 1);
+		       pfn, ps->msg, count);
 
 	/* Could do more checks here if page looks ok */
 	/*