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authorWu Fengguang <fengguang.wu@intel.com>2009-12-16 12:19:57 +0100
committerAndi Kleen <ak@linux.intel.com>2009-12-16 12:19:57 +0100
commitbd1ce5f91f545730df4af492f774d9d32f5da3cb (patch)
tree7d25f35cda1f37e30fd21bb2375f2693837d5ec5
parenta7560fc80f33cab33176ee78f146df22b28e3338 (diff)
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HWPOISON: avoid grabbing the page count multiple times during madvise injection
If page is double referenced in madvise_hwpoison() and __memory_failure(), remove_mapping() will fail because it expects page_count=2. Fix it by not grabbing extra page count in __memory_failure(). Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
-rw-r--r--mm/madvise.c1
-rw-r--r--mm/memory-failure.c8
2 files changed, 4 insertions, 5 deletions
diff --git a/mm/madvise.c b/mm/madvise.c
index 35b1479b7c9..18970aec0d2 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -238,7 +238,6 @@ static int madvise_hwpoison(unsigned long start, unsigned long end)
page_to_pfn(p), start);
/* Ignore return value for now */
__memory_failure(page_to_pfn(p), 0, 1);
- put_page(p);
}
return ret;
}
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 275f4e2df8a..4253e14fa70 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -627,7 +627,7 @@ static void action_result(unsigned long pfn, char *msg, int result)
}
static int page_action(struct page_state *ps, struct page *p,
- unsigned long pfn, int ref)
+ unsigned long pfn)
{
int result;
int count;
@@ -635,7 +635,7 @@ static int page_action(struct page_state *ps, struct page *p,
result = ps->action(p, pfn);
action_result(pfn, ps->msg, result);
- count = page_count(p) - 1 - ref;
+ count = page_count(p) - 1;
if (count != 0)
printk(KERN_ERR
"MCE %#lx: %s page still referenced by %d users\n",
@@ -773,7 +773,7 @@ int __memory_failure(unsigned long pfn, int trapno, int ref)
* In fact it's dangerous to directly bump up page count from 0,
* that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
*/
- if (!get_page_unless_zero(compound_head(p))) {
+ if (!ref && !get_page_unless_zero(compound_head(p))) {
action_result(pfn, "free or high order kernel", IGNORED);
return PageBuddy(compound_head(p)) ? 0 : -EBUSY;
}
@@ -821,7 +821,7 @@ int __memory_failure(unsigned long pfn, int trapno, int ref)
res = -EBUSY;
for (ps = error_states;; ps++) {
if (((p->flags | lru_flag)& ps->mask) == ps->res) {
- res = page_action(ps, p, pfn, ref);
+ res = page_action(ps, p, pfn);
break;
}
}