From: Mikulas Patocka <[email protected]>
commit a1cd6c2ae47ee10ff21e62475685d5b399e2ed4a upstream.
If we copy less than 8 bytes and if the destination crosses a cache
line, __copy_user_flushcache would invalidate only the first cache line.
This patch makes it invalidate the second cache line as well.
Fixes: 0aed55af88345b ("x86, uaccess: introduce copy_from_iter_flushcache for
pmem / cache-bypass operations")
Signed-off-by: Mikulas Patocka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jeff Moyer <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Ross Zwisler <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: <[email protected]>
Link:
https://lkml.kernel.org/r/alpine.lrh.2.02.2009161451140.21...@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/x86/lib/usercopy_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -118,7 +118,7 @@ long __copy_user_flushcache(void *dst, c
*/
if (size < 8) {
if (!IS_ALIGNED(dest, 4) || size != 4)
- clean_cache_range(dst, 1);
+ clean_cache_range(dst, size);
} else {
if (!IS_ALIGNED(dest, 8)) {
dest = ALIGN(dest, boot_cpu_data.x86_clflush_size);
