[RFC PATCH v6 08/11] x86: Insert endbr32/endbr64 to vDSO
From: Yu-cheng Yu <hidden>
Date: 2018-11-19 21:55:05
Also in:
linux-api, linux-arch, linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
From: "H.J. Lu" <redacted> 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 <redacted> --- arch/x86/entry/vdso/.gitignore | 4 ++++ arch/x86/entry/vdso/Makefile | 12 +++++++++++- arch/x86/entry/vdso/vdso-layout.lds.S | 1 + 3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/vdso/.gitignore b/arch/x86/entry/vdso/.gitignore
index aae8ffdd5880..552941fdfae0 100644
--- a/arch/x86/entry/vdso/.gitignore
+++ b/arch/x86/entry/vdso/.gitignore@@ -5,3 +5,7 @@ vdso32-sysenter-syms.lds vdso32-int80-syms.lds vdso-image-*.c vdso2c +vclock_gettime.S +vgetcpu.S +vclock_gettime.asm +vgetcpu.asm
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 141d415a8c80..0b1b464e7ae7 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 $(call if_changed,objcopy)
@@ -172,6 +176,12 @@ quiet_cmd_vdso = VDSO $@ VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \ $(call ld-option, --build-id) -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 acfd5ba7d943..cabaeedfed78 100644
--- a/arch/x86/entry/vdso/vdso-layout.lds.S
+++ b/arch/x86/entry/vdso/vdso-layout.lds.S@@ -74,6 +74,7 @@ SECTIONS .fake_shstrtab : { *(.fake_shstrtab) } :text + .note.gnu.property : { *(.note.gnu.property) } :text :note .note : { *(.note.*) } :text :note .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
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2.17.1