diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-retpoline-Support-retpoline-builds-with-Clang.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-retpoline-Support-retpoline-builds-with-Clang.patch | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-retpoline-Support-retpoline-builds-with-Clang.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-retpoline-Support-retpoline-builds-with-Clang.patch new file mode 100644 index 00000000..6caed4a9 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-retpoline-Support-retpoline-builds-with-Clang.patch @@ -0,0 +1,103 @@ +From 3de13a223fa7e5d0dc5bb20d87be73f686768daf Mon Sep 17 00:00:00 2001 +From: David Woodhouse <dwmw@amazon.co.uk> +Date: Mon, 19 Feb 2018 10:50:57 +0000 +Subject: [PATCH 11/14] x86/retpoline: Support retpoline builds with Clang + +commit 87358710c1fb4f1bf96bbe2349975ff9953fc9b2 upstream. + +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Reviewed-by: Thomas Gleixner <tglx@linutronix.de> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: arjan.van.de.ven@intel.com +Cc: bp@alien8.de +Cc: dave.hansen@intel.com +Cc: jmattson@google.com +Cc: karahmed@amazon.de +Cc: kvm@vger.kernel.org +Cc: pbonzini@redhat.com +Cc: rkrcmar@redhat.com +Link: http://lkml.kernel.org/r/1519037457-7643-5-git-send-email-dwmw@amazon.co.uk +Signed-off-by: Ingo Molnar <mingo@kernel.org> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/Makefile | 5 ++++- + include/linux/compiler-clang.h | 5 +++++ + include/linux/compiler-gcc.h | 4 ++++ + include/linux/init.h | 8 ++++---- + 4 files changed, 17 insertions(+), 5 deletions(-) + +diff --git a/arch/x86/Makefile b/arch/x86/Makefile +index cd22cb8..b609961 100644 +--- a/arch/x86/Makefile ++++ b/arch/x86/Makefile +@@ -184,7 +184,10 @@ KBUILD_AFLAGS += $(mflags-y) + + # Avoid indirect branches in kernel to deal with Spectre + ifdef CONFIG_RETPOLINE +- RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register) ++ 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 +diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h +index de17999..01225b0 100644 +--- a/include/linux/compiler-clang.h ++++ b/include/linux/compiler-clang.h +@@ -15,3 +15,8 @@ + * with any version that can compile the kernel + */ + #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) ++ ++/* Clang doesn't have a way to turn it off per-function, yet. */ ++#ifdef __noretpoline ++#undef __noretpoline ++#endif +diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h +index 928e5ca..362a1e17 100644 +--- a/include/linux/compiler-gcc.h ++++ b/include/linux/compiler-gcc.h +@@ -88,6 +88,10 @@ + #define __weak __attribute__((weak)) + #define __alias(symbol) __attribute__((alias(#symbol))) + ++#ifdef RETPOLINE ++#define __noretpoline __attribute__((indirect_branch("keep"))) ++#endif ++ + /* + * it doesn't make sense on ARM (currently the only user of __naked) + * to trace naked functions because then mcount is called without +diff --git a/include/linux/init.h b/include/linux/init.h +index 8e346d1..683508f 100644 +--- a/include/linux/init.h ++++ b/include/linux/init.h +@@ -5,10 +5,10 @@ + #include <linux/types.h> + + /* Built-in __init functions needn't be compiled with retpoline */ +-#if defined(RETPOLINE) && !defined(MODULE) +-#define __noretpoline __attribute__((indirect_branch("keep"))) ++#if defined(__noretpoline) && !defined(MODULE) ++#define __noinitretpoline __noretpoline + #else +-#define __noretpoline ++#define __noinitretpoline + #endif + + /* These macros are used to mark some functions or +@@ -46,7 +46,7 @@ + + /* These are for everybody (although not all archs will actually + discard it in modules) */ +-#define __init __section(.init.text) __cold notrace __latent_entropy __noretpoline ++#define __init __section(.init.text) __cold notrace __latent_entropy __noinitretpoline + #define __initdata __section(.init.data) + #define __initconst __section(.init.rodata) + #define __exitdata __section(.exit.data) +-- +2.7.4 + |