This is a note to let you know that I've just added the patch titled
x86/alternative: Use ALTERNATIVE_TERNARY() in _static_cpu_has()
to the 5.10-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:
x86-alternative-use-alternative_ternary-in-_static_cpu_has.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Jul 12 05:07:35 PM CEST 2022
From: Juergen Gross <jgross@xxxxxxxx>
Date: Thu, 11 Mar 2021 15:23:12 +0100
Subject: x86/alternative: Use ALTERNATIVE_TERNARY() in _static_cpu_has()
From: Juergen Gross <jgross@xxxxxxxx>
commit 2fe2a2c7a97c9bc32acc79154b75e754280f7867 upstream.
_static_cpu_has() contains a completely open coded version of
ALTERNATIVE_TERNARY(). Replace that with the macro instead.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20210311142319.4723-8-jgross@xxxxxxxx
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/cpufeature.h | 41 ++++++++------------------------------
1 file changed, 9 insertions(+), 32 deletions(-)
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -8,6 +8,7 @@
#include <asm/asm.h>
#include <linux/bitops.h>
+#include <asm/alternative.h>
enum cpuid_leafs
{
@@ -172,39 +173,15 @@ extern void clear_cpu_cap(struct cpuinfo
*/
static __always_inline bool _static_cpu_has(u16 bit)
{
- asm_volatile_goto("1: jmp 6f\n"
- "2:\n"
- ".skip -(((5f-4f) - (2b-1b)) > 0) * "
- "((5f-4f) - (2b-1b)),0x90\n"
- "3:\n"
- ".section .altinstructions,\"a\"\n"
- " .long 1b - .\n" /* src offset */
- " .long 4f - .\n" /* repl offset */
- " .word %P[always]\n" /* always replace */
- " .byte 3b - 1b\n" /* src len */
- " .byte 5f - 4f\n" /* repl len */
- " .byte 3b - 2b\n" /* pad len */
- ".previous\n"
- ".section .altinstr_replacement,\"ax\"\n"
- "4: jmp %l[t_no]\n"
- "5:\n"
- ".previous\n"
- ".section .altinstructions,\"a\"\n"
- " .long 1b - .\n" /* src offset */
- " .long 0\n" /* no replacement */
- " .word %P[feature]\n" /* feature bit */
- " .byte 3b - 1b\n" /* src len */
- " .byte 0\n" /* repl len */
- " .byte 0\n" /* pad len */
- ".previous\n"
- ".section .altinstr_aux,\"ax\"\n"
- "6:\n"
- " testb %[bitnum],%[cap_byte]\n"
- " jnz %l[t_yes]\n"
- " jmp %l[t_no]\n"
- ".previous\n"
+ asm_volatile_goto(
+ ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]")
+ ".section .altinstr_aux,\"ax\"\n"
+ "6:\n"
+ " testb %[bitnum],%[cap_byte]\n"
+ " jnz %l[t_yes]\n"
+ " jmp %l[t_no]\n"
+ ".previous\n"
: : [feature] "i" (bit),
- [always] "i" (X86_FEATURE_ALWAYS),
[bitnum] "i" (1 << (bit & 7)),
[cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
: : t_yes, t_no);
Patches currently in stable-queue which might be from jgross@xxxxxxxx are
queue-5.10/x86-alternative-merge-include-files.patch
queue-5.10/x86-xen-support-objtool-vmlinux.o-validation-in-xen-head.s.patch
queue-5.10/x86-alternative-support-not-feature.patch
queue-5.10/x86-xen-support-objtool-validation-in-xen-asm.s.patch
queue-5.10/x86-alternative-support-alternative_ternary.patch
queue-5.10/x86-alternative-use-alternative_ternary-in-_static_cpu_has.patch
