* [PATCH] x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80"
@ 2018-06-27 5:45 Andy Lutomirski
2018-06-27 8:51 ` Li Zhijian
0 siblings, 1 reply; 2+ messages in thread
From: Andy Lutomirski @ 2018-06-27 5:45 UTC (permalink / raw)
To: x86, LKML; +Cc: Borislav Petkov, zhijianx.li, Andy Lutomirski, stable
Commit 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int
$0x80") was busted. My original patch had a minor conflict with
some of the nospec changes. git apply is very clever and silently
accepted the patch by making the same changes to a different
function in the same file. There was obviously a huge offset, but
git apply for some reason doesn't feel any need to say so.
Move the changes to the correct function. Now the
test_syscall_vdso_32 selftests passes.
If anyone cares to observe the original problem, try applying the
patch at
https://lore.kernel.org/lkml/d4c4d9985fbe64f8c9e19291886453914b48caee.1523975710.git.luto@kernel.org/raw
to the kernel at 316d097c4cd4e7f2ef50c40cff2db266593c4ec4. git am and
git apply accept the patch without any complaints at all. patch -p1
at least prints out a message about the huge offset.
Reported-by: zhijianx.li@intel.com
Fixes: 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80")
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/entry/entry_64_compat.S | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 9de7f1e1dede..7d0df78db727 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -84,13 +84,13 @@ ENTRY(entry_SYSENTER_compat)
pushq %rdx /* pt_regs->dx */
pushq %rcx /* pt_regs->cx */
pushq $-ENOSYS /* pt_regs->ax */
- pushq %r8 /* pt_regs->r8 */
+ pushq $0 /* pt_regs->r8 = 0 */
xorl %r8d, %r8d /* nospec r8 */
- pushq %r9 /* pt_regs->r9 */
+ pushq $0 /* pt_regs->r9 = 0 */
xorl %r9d, %r9d /* nospec r9 */
- pushq %r10 /* pt_regs->r10 */
+ pushq $0 /* pt_regs->r10 = 0 */
xorl %r10d, %r10d /* nospec r10 */
- pushq %r11 /* pt_regs->r11 */
+ pushq $0 /* pt_regs->r11 = 0 */
xorl %r11d, %r11d /* nospec r11 */
pushq %rbx /* pt_regs->rbx */
xorl %ebx, %ebx /* nospec rbx */
@@ -374,13 +374,13 @@ ENTRY(entry_INT80_compat)
pushq %rcx /* pt_regs->cx */
xorl %ecx, %ecx /* nospec cx */
pushq $-ENOSYS /* pt_regs->ax */
- pushq $0 /* pt_regs->r8 = 0 */
+ pushq %r8 /* pt_regs->r8 */
xorl %r8d, %r8d /* nospec r8 */
- pushq $0 /* pt_regs->r9 = 0 */
+ pushq %r9 /* pt_regs->r9 */
xorl %r9d, %r9d /* nospec r9 */
- pushq $0 /* pt_regs->r10 = 0 */
+ pushq %r10 /* pt_regs->r10*/
xorl %r10d, %r10d /* nospec r10 */
- pushq $0 /* pt_regs->r11 = 0 */
+ pushq %r11 /* pt_regs->r11 */
xorl %r11d, %r11d /* nospec r11 */
pushq %rbx /* pt_regs->rbx */
xorl %ebx, %ebx /* nospec rbx */
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80"
2018-06-27 5:45 [PATCH] x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80" Andy Lutomirski
@ 2018-06-27 8:51 ` Li Zhijian
0 siblings, 0 replies; 2+ messages in thread
From: Li Zhijian @ 2018-06-27 8:51 UTC (permalink / raw)
To: Andy Lutomirski, x86, LKML; +Cc: Borislav Petkov, stable
On 6/27/2018 1:45 PM, Andy Lutomirski wrote:
> Commit 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int
> $0x80") was busted. My original patch had a minor conflict with
> some of the nospec changes. git apply is very clever and silently
> accepted the patch by making the same changes to a different
> function in the same file. There was obviously a huge offset, but
> git apply for some reason doesn't feel any need to say so.
>
> Move the changes to the correct function. Now the
> test_syscall_vdso_32 selftests passes.
>
> If anyone cares to observe the original problem, try applying the
> patch at
> https://lore.kernel.org/lkml/d4c4d9985fbe64f8c9e19291886453914b48caee.1523975710.git.luto@kernel.org/raw
> to the kernel at 316d097c4cd4e7f2ef50c40cff2db266593c4ec4. git am and
> git apply accept the patch without any complaints at all. patch -p1
> at least prints out a message about the huge offset.
>
> Reported-by: zhijianx.li@intel.com
> Fixes: 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80")
> Cc: stable@vger.kernel.org
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
Tested-by: Li Zhijian <zhijianx.li@intel.com>
> ---
> arch/x86/entry/entry_64_compat.S | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
> index 9de7f1e1dede..7d0df78db727 100644
> --- a/arch/x86/entry/entry_64_compat.S
> +++ b/arch/x86/entry/entry_64_compat.S
> @@ -84,13 +84,13 @@ ENTRY(entry_SYSENTER_compat)
> pushq %rdx /* pt_regs->dx */
> pushq %rcx /* pt_regs->cx */
> pushq $-ENOSYS /* pt_regs->ax */
> - pushq %r8 /* pt_regs->r8 */
> + pushq $0 /* pt_regs->r8 = 0 */
> xorl %r8d, %r8d /* nospec r8 */
> - pushq %r9 /* pt_regs->r9 */
> + pushq $0 /* pt_regs->r9 = 0 */
> xorl %r9d, %r9d /* nospec r9 */
> - pushq %r10 /* pt_regs->r10 */
> + pushq $0 /* pt_regs->r10 = 0 */
> xorl %r10d, %r10d /* nospec r10 */
> - pushq %r11 /* pt_regs->r11 */
> + pushq $0 /* pt_regs->r11 = 0 */
> xorl %r11d, %r11d /* nospec r11 */
> pushq %rbx /* pt_regs->rbx */
> xorl %ebx, %ebx /* nospec rbx */
> @@ -374,13 +374,13 @@ ENTRY(entry_INT80_compat)
> pushq %rcx /* pt_regs->cx */
> xorl %ecx, %ecx /* nospec cx */
> pushq $-ENOSYS /* pt_regs->ax */
> - pushq $0 /* pt_regs->r8 = 0 */
> + pushq %r8 /* pt_regs->r8 */
> xorl %r8d, %r8d /* nospec r8 */
> - pushq $0 /* pt_regs->r9 = 0 */
> + pushq %r9 /* pt_regs->r9 */
> xorl %r9d, %r9d /* nospec r9 */
> - pushq $0 /* pt_regs->r10 = 0 */
> + pushq %r10 /* pt_regs->r10*/
> xorl %r10d, %r10d /* nospec r10 */
> - pushq $0 /* pt_regs->r11 = 0 */
> + pushq %r11 /* pt_regs->r11 */
> xorl %r11d, %r11d /* nospec r11 */
> pushq %rbx /* pt_regs->rbx */
> xorl %ebx, %ebx /* nospec rbx */
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2018-06-27 8:51 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-06-27 5:45 [PATCH] x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80" Andy Lutomirski
2018-06-27 8:51 ` Li Zhijian
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).