This is a note to let you know that I've just added the patch titled
x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end}
to the 4.15-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:
x86usercopy_Replace_open_coded_stacclac_with___uaccess_begin_end.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
Subject: x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end}
From: Dan Williams dan.j.williams@xxxxxxxxx
Date: Mon Jan 29 17:02:44 2018 -0800
From: Dan Williams dan.j.williams@xxxxxxxxx
commit b5c4ae4f35325d520b230bab6eb3310613b72ac1
In preparation for converting some __uaccess_begin() instances to
__uacess_begin_nospec(), make sure all 'from user' uaccess paths are
using the _begin(), _end() helpers rather than open-coded stac() and
clac().
No functional changes.
Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: kernel-hardening@xxxxxxxxxxxxxxxxxx
Cc: gregkh@xxxxxxxxxxxxxxxxxxx
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: torvalds@xxxxxxxxxxxxxxxxxxxx
Cc: alan@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/151727416438.33451.17309465232057176966.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/lib/usercopy_32.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -331,12 +331,12 @@ do { \
unsigned long __copy_user_ll(void *to, const void *from, unsigned long n)
{
- stac();
+ __uaccess_begin();
if (movsl_is_ok(to, from, n))
__copy_user(to, from, n);
else
n = __copy_user_intel(to, from, n);
- clac();
+ __uaccess_end();
return n;
}
EXPORT_SYMBOL(__copy_user_ll);
@@ -344,7 +344,7 @@ EXPORT_SYMBOL(__copy_user_ll);
unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
unsigned long n)
{
- stac();
+ __uaccess_begin();
#ifdef CONFIG_X86_INTEL_USERCOPY
if (n > 64 && static_cpu_has(X86_FEATURE_XMM2))
n = __copy_user_intel_nocache(to, from, n);
@@ -353,7 +353,7 @@ unsigned long __copy_from_user_ll_nocach
#else
__copy_user(to, from, n);
#endif
- clac();
+ __uaccess_end();
return n;
}
EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
Patches currently in stable-queue which might be from mingo@xxxxxxxxxx are
queue-4.15/x86_Introduce_barrier_nospec.patch
queue-4.15/x86_Introduce___uaccess_begin_nospec()_and_uaccess_try_nospec.patch
queue-4.15/x86usercopy_Replace_open_coded_stacclac_with___uaccess_begin_end.patch