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authorWu Fengguang <fengguang.wu@intel.com>2009-12-16 12:19:58 +0100
committerAndi Kleen <ak@linux.intel.com>2009-12-16 12:19:58 +0100
commit1668bfd5be9d8a52536c4865000fbbe065a3613b (patch)
tree85f060960de6e27f6933d56fcfd194b25ddbc460
parent82ba011b9041dd31c15e4f63797b08aa0a288e61 (diff)
downloadop-kernel-dev-1668bfd5be9d8a52536c4865000fbbe065a3613b.zip
op-kernel-dev-1668bfd5be9d8a52536c4865000fbbe065a3613b.tar.gz
HWPOISON: abort on failed unmap
Don't try to isolate a still mapped page. Otherwise we will hit the BUG_ON(page_mapped(page)) in __remove_from_page_cache(). Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
-rw-r--r--mm/memory-failure.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 3338c44..b62287d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -655,7 +655,7 @@ static int page_action(struct page_state *ps, struct page *p,
* Do all that is necessary to remove user space mappings. Unmap
* the pages and send SIGBUS to the processes if the data was dirty.
*/
-static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
+static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
int trapno)
{
enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
@@ -665,15 +665,18 @@ static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
int i;
int kill = 1;
- if (PageReserved(p) || PageCompound(p) || PageSlab(p) || PageKsm(p))
- return;
+ if (PageReserved(p) || PageSlab(p))
+ return SWAP_SUCCESS;
/*
* This check implies we don't kill processes if their pages
* are in the swap cache early. Those are always late kills.
*/
if (!page_mapped(p))
- return;
+ return SWAP_SUCCESS;
+
+ if (PageCompound(p) || PageKsm(p))
+ return SWAP_FAIL;
if (PageSwapCache(p)) {
printk(KERN_ERR
@@ -735,6 +738,8 @@ static void hwpoison_user_mappings(struct page *p, unsigned long pfn,
*/
kill_procs_ao(&tokill, !!PageDirty(p), trapno,
ret != SWAP_SUCCESS, pfn);
+
+ return ret;
}
int __memory_failure(unsigned long pfn, int trapno, int flags)
@@ -807,8 +812,13 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
/*
* Now take care of user space mappings.
+ * Abort on fail: __remove_from_page_cache() assumes unmapped page.
*/
- hwpoison_user_mappings(p, pfn, trapno);
+ if (hwpoison_user_mappings(p, pfn, trapno) != SWAP_SUCCESS) {
+ printk(KERN_ERR "MCE %#lx: cannot unmap page, give up\n", pfn);
+ res = -EBUSY;
+ goto out;
+ }
/*
* Torn down by someone else?
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