diff mbox series

[v8,08/14] x86/vdso: Insert endbr32/endbr64 to vDSO

Message ID 20190813205359.12196-9-yu-cheng.yu@intel.com (mailing list archive)
State New, archived
Headers show
Series Control-flow Enforcement: Branch Tracking, PTRACE | expand

Commit Message

Yu-cheng Yu Aug. 13, 2019, 8:53 p.m. UTC 
From: "H.J. Lu" <hjl.tools@gmail.com>

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.

Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
 arch/x86/entry/vdso/Makefile          | 12 +++++++++++-
 arch/x86/entry/vdso/vdso-layout.lds.S |  1 +
 2 files changed, 12 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 8df549138193..1e6a95881e73 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -114,13 +114,17 @@  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)
@@ -178,6 +182,12 @@  quiet_cmd_vdso = VDSO    $@
 
 VDSO_LDFLAGS = -shared --hash-style=both --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
 
 quiet_cmd_vdso_and_check = VDSO    $@
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