From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: [PATCH v7 09/14] x86/vdso: Insert endbr32/endbr64 to vDSO Date: Thu, 6 Jun 2019 13:09:21 -0700 Message-ID: <20190606200926.4029-10-yu-cheng.yu@intel.com> References: <20190606200926.4029-1-yu-cheng.yu@intel.com> Return-path: In-Reply-To: <20190606200926.4029-1-yu-cheng.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit List-Id: linux-api@vger.kernel.org From: "H.J. Lu" When Intel indirect branch tracking is enabled, functions in vDSO which may be called indirectly must have endbr32 or endbr64 as the first instruction. Compiler must support -fcf-protection=branch so that it can be used to compile vDSO. Signed-off-by: H.J. Lu --- arch/x86/entry/vdso/Makefile | 12 +++++++++++- arch/x86/entry/vdso/vdso-layout.lds.S | 1 + 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 42fe42e82baf..718fc17b0d67 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -108,13 +108,17 @@ vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F) # Convert 64bit object file to x32 for x32 vDSO. quiet_cmd_x32 = X32 $@ - cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@ + cmd_x32 = $(OBJCOPY) -R .note.gnu.property -O elf32-x86-64 $< $@ $(obj)/%-x32.o: $(obj)/%.o FORCE $(call if_changed,x32) targets += vdsox32.lds $(vobjx32s-y) +ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER + $(obj)/vclock_gettime.o $(obj)/vgetcpu.o $(obj)/vdso32/vclock_gettime.o: KBUILD_CFLAGS += -fcf-protection=branch +endif + $(obj)/%.so: OBJCOPYFLAGS := -S $(obj)/%.so: $(obj)/%.so.dbg FORCE $(call if_changed,objcopy) @@ -173,6 +177,12 @@ quiet_cmd_vdso = VDSO $@ VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \ $(call ld-option, --build-id) $(call ld-option, --eh-frame-hdr) \ -Bsymbolic +ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER + VDSO_LDFLAGS += $(call ldoption, -z$(comma)ibt) +endif +ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER + VDSO_LDFLAGS += $(call ldoption, -z$(comma)shstk) +endif GCOV_PROFILE := n # diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S index 93c6dc7812d0..3fea2ce318bc 100644 --- a/arch/x86/entry/vdso/vdso-layout.lds.S +++ b/arch/x86/entry/vdso/vdso-layout.lds.S @@ -52,6 +52,7 @@ SECTIONS *(.gnu.linkonce.b.*) } :text + .note.gnu.property : { *(.note.gnu.property) } :text :note .note : { *(.note.*) } :text :note .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr -- 2.17.1