From: Mikulas Patocka <mpato...@redhat.com>
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 <mpato...@redhat.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.wiilli...@intel.com>
Cc: Jan Kara <j...@suse.cz>
Cc: Jeff Moyer <jmo...@redhat.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Toshi Kani <toshi.k...@hpe.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Matthew Wilcox <mawil...@microsoft.com>
Cc: Ross Zwisler <ross.zwis...@linux.intel.com>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: <sta...@vger.kernel.org>
Link:
https://lkml.kernel.org/r/alpine.lrh.2.02.2009161451140.21...@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
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);
