4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Waiman Long <[email protected]> commit 1df37383a8aeabb9b418698f0bcdffea01f4b1b2 upstream. 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 <[email protected]> Signed-off-by: Waiman Long <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: David Woodhouse <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Kees Cook <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Tim Chen <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Arjan van de Ven <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Paul Turner <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: David Woodhouse <[email protected]> [jwang: cherry pick to 4.4] Signed-off-by: Jack Wang <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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)
