From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754589AbbIAWuN (ORCPT ); Tue, 1 Sep 2015 18:50:13 -0400 Received: from mail.kernel.org ([198.145.29.136]:47461 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752996AbbIAWmA (ORCPT ); Tue, 1 Sep 2015 18:42:00 -0400 From: Andy Lutomirski To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Brian Gerst , Denys Vlasenko , Linus Torvalds , Borislav Petkov , Andy Lutomirski Subject: [RFC 09/30] x86/vdso: Define BUILD_VDSO while building and emit .eh_frame in asm Date: Tue, 1 Sep 2015 15:41:09 -0700 Message-Id: <7f7550b7a42743b219df89349e6b8d52908653a3.1441146105.git.luto@kernel.org> X-Mailer: git-send-email 2.4.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For the vDSO, user code wants runtime unwind info. Make sure that, if we use .cfi directives, we generate it. Signed-off-by: Andy Lutomirski --- arch/x86/entry/vdso/Makefile | 4 ++-- arch/x86/include/asm/dwarf2.h | 13 ++++++++++--- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 3bfb39e7b8b2..265c0ed68118 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -67,7 +67,7 @@ $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \ -fno-omit-frame-pointer -foptimize-sibling-calls \ - -DDISABLE_BRANCH_PROFILING + -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO $(vobjs): KBUILD_CFLAGS += $(CFL) @@ -131,7 +131,7 @@ targets += vdso32/vdso32.lds targets += vdso32/note.o vdso32/vclock_gettime.o vdso32/system_call.o targets += vdso32/vclock_gettime.o -KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) +KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32) $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32 diff --git a/arch/x86/include/asm/dwarf2.h b/arch/x86/include/asm/dwarf2.h index de1cdaf4d743..09133ba032b3 100644 --- a/arch/x86/include/asm/dwarf2.h +++ b/arch/x86/include/asm/dwarf2.h @@ -36,15 +36,22 @@ #endif #if defined(CONFIG_AS_CFI_SECTIONS) && defined(__ASSEMBLY__) +#ifndef BUILD_VDSO /* * Emit CFI data in .debug_frame sections, not .eh_frame sections. * The latter we currently just discard since we don't do DWARF * unwinding at runtime. So only the offline DWARF information is - * useful to anyone. Note we should not use this directive if this - * file is used in the vDSO assembly, or if vmlinux.lds.S gets - * changed so it doesn't discard .eh_frame. + * useful to anyone. Note we should not use this directive if + * vmlinux.lds.S gets changed so it doesn't discard .eh_frame. */ .cfi_sections .debug_frame +#else + /* + * For the vDSO, emit both runtime unwind information and debug + * symbols for the .dbg file. + */ + .cfi_sections .eh_frame, .debug_frame +#endif #endif #else -- 2.4.3