diff mbox series

[RFC,v6,10/11] x86/vsyscall/64: Add ENDBR64 to vsyscall entry points

Message ID 20181119214934.6174-11-yu-cheng.yu@intel.com (mailing list archive)
State New, archived
Headers show
Series Control-flow Enforcement: Branch Tracking, PTRACE | expand

Commit Message

Yu-cheng Yu Nov. 19, 2018, 9:49 p.m. UTC 
From: "H.J. Lu" <hjl.tools@gmail.com>

Add ENDBR64 to vsyscall entry points.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
 arch/x86/entry/vsyscall/vsyscall_emu_64.S | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Andy Lutomirski Nov. 19, 2018, 10:22 p.m. UTC | #1 
On Mon, Nov 19, 2018 at 1:55 PM Yu-cheng Yu <yu-cheng.yu@intel.com> wrote:
>
> From: "H.J. Lu" <hjl.tools@gmail.com>
>
> Add ENDBR64 to vsyscall entry points.
>
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

Acked-by: Andy Lutomirski <luto@kernel.org>

although the scenarios where this matters will be extremely rare,
given that this code is mapped NX :)  Tools like 'pin' may care.

--Andy
diff mbox series

Patch

diff --git a/arch/x86/entry/vsyscall/vsyscall_emu_64.S b/arch/x86/entry/vsyscall/vsyscall_emu_64.S
index c9596a9af159..08554445bef1 100644
--- a/arch/x86/entry/vsyscall/vsyscall_emu_64.S
+++ b/arch/x86/entry/vsyscall/vsyscall_emu_64.S
@@ -18,16 +18,25 @@  __PAGE_ALIGNED_DATA
 	.type __vsyscall_page, @object
 __vsyscall_page:
 
+#ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER
+	endbr64
+#endif
 	mov $__NR_gettimeofday, %rax
 	syscall
 	ret
 
 	.balign 1024, 0xcc
+#ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER
+	endbr64
+#endif
 	mov $__NR_time, %rax
 	syscall
 	ret
 
 	.balign 1024, 0xcc
+#ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER
+	endbr64
+#endif
 	mov $__NR_getcpu, %rax
 	syscall
 	ret