[PATCH 3.13 003/163] percpu: perform tlb flush after pcpu_map_pages() failure

Kamal Mostafa kamal at canonical.com
Thu Oct 9 21:00:28 UTC 2014


3.13.11.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tejun Heo <tj at kernel.org>

commit 849f5169097e1ba35b90ac9df76b5bb6f9c0aabd upstream.

If pcpu_map_pages() fails midway, it unmaps the already mapped pages.
Currently, it doesn't flush tlb after the partial unmapping.  This may
be okay in most cases as the established mapping hasn't been used at
that point but it can go wrong and when it goes wrong it'd be
extremely difficult to track down.

Flush tlb after the partial unmapping.

Signed-off-by: Tejun Heo <tj at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 mm/percpu-vm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c
index 8d9bb2c..5110816 100644
--- a/mm/percpu-vm.c
+++ b/mm/percpu-vm.c
@@ -272,6 +272,7 @@ err:
 		__pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start),
 				   page_end - page_start);
 	}
+	pcpu_post_unmap_tlb_flush(chunk, page_start, page_end);
 	return err;
 }
 
-- 
1.9.1





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