The patch titled
Subject: arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
has been added to the -mm tree. Its filename is
arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Subject: arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
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.
Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 0aed55af88345b ("x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations")
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
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: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/lib/usercopy_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/lib/usercopy_64.c~arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback
+++ a/arch/x86/lib/usercopy_64.c
@@ -120,7 +120,7 @@ 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 -mm which might be from mpatocka@xxxxxxxxxx are
arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch
