Re: [RFC PATCH v6 08/11] x86: Insert endbr32/endbr64 to vDSO

From
Yu-cheng Yu <hidden>
Date
2018-11-19 22:48:51
Also in
linux-arch, linux-doc, linux-mm, lkml
Reply to
Andy Lutomirski, 2018-11-19
On Mon, 2018-11-19 at 14:17 -0800, Andy Lutomirski wrote:
On Mon, Nov 19, 2018 at 1:55 PM Yu-cheng Yu [off-list ref] wrote:
quoted
From: "H.J. Lu" <redacted>

When Intel indirect branch tracking is enabled, functions in vDSO which
may be called indirectly must have endbr32 or endbr64 as the first
instruction.  Compiler must support -fcf-protection=branch so that it
can be used to compile vDSO.

Signed-off-by: H.J. Lu <redacted>
---
 arch/x86/entry/vdso/.gitignore        |  4 ++++
 arch/x86/entry/vdso/Makefile          | 12 +++++++++++-
 arch/x86/entry/vdso/vdso-layout.lds.S |  1 +
 3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/vdso/.gitignore b/arch/x86/entry/vdso/.gitignore
index aae8ffdd5880..552941fdfae0 100644
--- a/arch/x86/entry/vdso/.gitignore
+++ b/arch/x86/entry/vdso/.gitignore
@@ -5,3 +5,7 @@ vdso32-sysenter-syms.lds
 vdso32-int80-syms.lds
 vdso-image-*.c
 vdso2c
+vclock_gettime.S
+vgetcpu.S
+vclock_gettime.asm
+vgetcpu.asm

What's this hunk about?
We used to allow using non-CET capable BINUTILS and the Makefile would create
these.  I will remove them from the patch.

Yu-cheng
Thread (17 messages) 17 messages, 2 authors, last reply 2018-11-19
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