[patch 2/6] x86, PAT: Change order of cpa and free in set_memory_wb

[venkatesh . pallipadi]

To be free of aliasing due to races, set_memory_* interfaces should
follow ordering of reserving, changing memtype to UC/WC, changing
memtype back to WB followed by free.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
---
 arch/x86/mm/pageattr.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 1224865..38dc61f 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1007,15 +1007,19 @@ int _set_memory_wb(unsigned long addr, int numpages)
 
 int set_memory_wb(unsigned long addr, int numpages)
 {
+	int ret = _set_memory_wb(addr, numpages);
 	free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
-
-	return _set_memory_wb(addr, numpages);
+	return ret;
 }
 EXPORT_SYMBOL(set_memory_wb);
 
 int set_memory_array_wb(unsigned long *addr, int addrinarray)
 {
 	int i;
+	int ret;
+
+	ret = change_page_attr_clear(addr, addrinarray,
+				      __pgprot(_PAGE_CACHE_MASK), 1);
 
 	for (i = 0; i < addrinarray; i++) {
 		unsigned long start = __pa(addr[i]);
@@ -1028,8 +1032,7 @@ int set_memory_array_wb(unsigned long *addr, int addrinarray)
 		}
 		free_memtype(start, end);
 	}
-	return change_page_attr_clear(addr, addrinarray,
-				      __pgprot(_PAGE_CACHE_MASK), 1);
+	return ret;
 }
 EXPORT_SYMBOL(set_memory_array_wb);
 
-- 
1.6.0.6

-- 

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