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| author | Peter Zijlstra <peterz@infradead.org> | 2018-02-06 11:46:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-15 12:54:38 +0300 |
| commit | c3b9f72606ac4fda901ac6ee9040952e854422fb (patch) | |
| tree | 538cda67757be8014d38c784c580f4f22319cb1b | |
| parent | a69898c9eb0a2eac477a980e4b94d2f7f3ff0a43 (diff) | |
| download | linux-c3b9f72606ac4fda901ac6ee9040952e854422fb.tar.xz | |
objtool, retpolines: Integrate objtool with retpoline support more closely
commit d5028ba8ee5a18c9d0bb926d883c28b370f89009 upstream.
Disable retpoline validation in objtool if your compiler sucks, and otherwise
select the validation stuff for CONFIG_RETPOLINE=y (most builds would already
have it set due to ORC).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Makefile | 5 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/Makefile | 10 | ||||
| -rw-r--r-- | scripts/Makefile.build | 2 |
4 files changed, 11 insertions, 7 deletions
@@ -494,6 +494,11 @@ KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) endif +RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register +RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk +RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG))) +export RETPOLINE_CFLAGS + ifeq ($(config-targets),1) # =========================================================================== # *config targets only - make sure prerequisites are updated, and descend diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 559b37bf5a2e..7483cd514c32 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -431,6 +431,7 @@ config GOLDFISH config RETPOLINE bool "Avoid speculative indirect branches in kernel" default y + select STACK_VALIDATION if HAVE_STACK_VALIDATION help Compile kernel with the retpoline compiler options to guard against kernel-to-user data leaks by avoiding speculative indirect diff --git a/arch/x86/Makefile b/arch/x86/Makefile index dbc7d0ed2eaa..498c1b812300 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -232,13 +232,9 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables # Avoid indirect branches in kernel to deal with Spectre ifdef CONFIG_RETPOLINE - RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register - RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk - - RETPOLINE_CFLAGS += $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG))) - ifneq ($(RETPOLINE_CFLAGS),) - KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE - endif +ifneq ($(RETPOLINE_CFLAGS),) + KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE +endif endif archscripts: scripts_basic diff --git a/scripts/Makefile.build b/scripts/Makefile.build index be9e5deb58ba..7143da06d702 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -272,8 +272,10 @@ else objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable) endif ifdef CONFIG_RETPOLINE +ifneq ($(RETPOLINE_CFLAGS),) objtool_args += --retpoline endif +endif ifdef CONFIG_MODVERSIONS |