From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753391AbeCQOaI (ORCPT ); Sat, 17 Mar 2018 10:30:08 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:54308 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752676AbeCQO3x (ORCPT ); Sat, 17 Mar 2018 10:29:53 -0400 X-Google-Smtp-Source: AG47ELvKY+dnbgrOlVksuJgLKnia6Y9la/4oYazuD/vi9DEp6gAXYTRMOtCCZ7on9YuzHOeB6xC72w== From: jason.vas.dias@gmail.com To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, tglx@linutronix.de, mingo@kernel.org, peterz@infradead.org, andi@firstfloor.org Subject: [PATCH v4.16-rc5 2/2] x86/vdso: VDSO should handle clock_gettime(CLOCK_MONOTONIC_RAW) without syscall Date: Sat, 17 Mar 2018 14:29:34 +0000 Message-Id: <1521296974-12142-3-git-send-email-jason.vas.dias@gmail.com> X-Mailer: git-send-email 2.8.2 In-Reply-To: <1521296974-12142-1-git-send-email-jason.vas.dias@gmail.com> References: <1521296974-12142-1-git-send-email-jason.vas.dias@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch allows compilation to succeed with compilers that support -DRETPOLINE - it was kindly contributed by H.J. Liu in GCC Bugzilla: 84908 : https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84908 Apparently the GCC retpoline implementation has a limitation that it cannot handle switch statements with more than 5 clauses, which vclock_gettime.c's __vdso_clock_gettime function now contains. The automated test builds should now succeed with this patch. diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 1943aeb..cb64e10 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -76,7 +76,7 @@ CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ -fno-omit-frame-pointer -foptimize-sibling-calls \ -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO -$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) $(CFL) +$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS) -DRETPOLINE,$(KBUILD_CFLAGS)) $(CFL) # # vDSO code runs in userspace and -pg doesn't help with profiling anyway. @@ -143,6 +143,7 @@ KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32)) +KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS) -DRETPOLINE,$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector) KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)