This is a note to let you know that I've just added the patch titled
arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arch-x86-lib-usercopy_64.c-fix-__copy_user_flushcache-cache-writeback.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a1cd6c2ae47ee10ff21e62475685d5b399e2ed4a Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Date: Fri, 25 Sep 2020 21:19:24 -0700
Subject: arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
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 <mpatocka@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Dan Williams <dan.j.wiilliams@xxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
Patches currently in stable-queue which might be from mpatocka@xxxxxxxxxx are
queue-4.14/arch-x86-lib-usercopy_64.c-fix-__copy_user_flushcache-cache-writeback.patch
