4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Waiman Long <long...@redhat.com>
(cherry picked from commit 1df37383a8aeabb9b418698f0bcdffea01f4b1b2)
It doesn't make sense to have an indirect call thunk with esp/rsp as
retpoline code won't work correctly with the stack pointer register.
Removing it will help compiler writers to catch error in case such
a thunk call is emitted incorrectly.
Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support")
Suggested-by: Jeff Law <l...@redhat.com>
Signed-off-by: Waiman Long <long...@redhat.com>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Acked-by: David Woodhouse <d...@amazon.co.uk>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: Kees Cook <keesc...@google.com>
Cc: Andi Kleen <a...@linux.intel.com>
Cc: Tim Chen <tim.c.c...@linux.intel.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Jiri Kosina <ji...@kernel.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Dave Hansen <dave.han...@intel.com>
Cc: Josh Poimboeuf <jpoim...@redhat.com>
Cc: Arjan van de Ven <ar...@linux.intel.com>
Cc: Greg Kroah-Hartman <gre...@linux-foundation.org>
Cc: Paul Turner <p...@google.com>
Link:
https://lkml.kernel.org/r/1516658974-27852-1-git-send-email-long...@redhat.com
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/x86/include/asm/asm-prototypes.h | 1 -
arch/x86/lib/retpoline.S | 1 -
2 files changed, 2 deletions(-)
--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -37,5 +37,4 @@ INDIRECT_THUNK(dx)
INDIRECT_THUNK(si)
INDIRECT_THUNK(di)
INDIRECT_THUNK(bp)
-INDIRECT_THUNK(sp)
#endif /* CONFIG_RETPOLINE */
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -36,7 +36,6 @@ GENERATE_THUNK(_ASM_DX)
GENERATE_THUNK(_ASM_SI)
GENERATE_THUNK(_ASM_DI)
GENERATE_THUNK(_ASM_BP)
-GENERATE_THUNK(_ASM_SP)
#ifdef CONFIG_64BIT
GENERATE_THUNK(r8)
GENERATE_THUNK(r9)
