Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754369AbbGQQ5h (ORCPT ); Fri, 17 Jul 2015 12:57:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32967 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754263AbbGQQ5e (ORCPT ); Fri, 17 Jul 2015 12:57:34 -0400 From: Josh Poimboeuf To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , x86@kernel.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 07/21] x86/paravirt: Fix frame pointer usage in PV_CALLEE_SAVE_REGS_THUNK Date: Fri, 17 Jul 2015 11:47:23 -0500 Message-Id: <0faa58b24a9273545451720f433beeb8fcb974d6.1437150175.git.jpoimboe@redhat.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1967 Lines: 56 A function created with the PV_CALLEE_SAVE_REGS_THUNK macro doesn't set up a new stack frame before the call instruction, which breaks frame pointer convention if CONFIG_FRAME_POINTER is enabled and can result in a bad stack trace. Also, the thunk functions aren't annotated as ELF callable functions. Create a stack frame when CONFIG_FRAME_POINTER is enabled and add the ELF function type. Signed-off-by: Josh Poimboeuf --- arch/x86/include/asm/paravirt.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index c2be037..2545f3e 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -13,6 +13,7 @@ #include #include #include +#include static inline int paravirt_enabled(void) { @@ -772,15 +773,19 @@ static __always_inline void __ticket_unlock_kick(struct arch_spinlock *lock, * call. The return value in rax/eax will not be saved, even for void * functions. */ +#define PV_THUNK_NAME(func) "__raw_callee_save_" #func #define PV_CALLEE_SAVE_REGS_THUNK(func) \ extern typeof(func) __raw_callee_save_##func; \ \ asm(".pushsection .text;" \ - ".globl __raw_callee_save_" #func " ; " \ - "__raw_callee_save_" #func ": " \ + ".globl " PV_THUNK_NAME(func) ";" \ + ".type " PV_THUNK_NAME(func) ", @function;" \ + PV_THUNK_NAME(func) ":" \ + FRAME \ PV_SAVE_ALL_CALLER_REGS \ "call " #func ";" \ PV_RESTORE_ALL_CALLER_REGS \ + ENDFRAME \ "ret;" \ ".popsection") -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/