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| author | Zhenzhong Duan <zhenzhong.duan@oracle.com> | 2018-11-02 01:45:41 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-11-28 11:57:03 +0100 |
| commit | 4cd24de3a0980bf3100c9dcb08ef65ca7c31af48 (patch) | |
| tree | e8358f10ec5689cdda1d7ad33491c607d15766c6 /arch/x86/Makefile | |
| parent | 2e6e902d185027f8e3cb8b7305238f7e35d6a436 (diff) | |
| download | linux-4cd24de3a0980bf3100c9dcb08ef65ca7c31af48.tar.bz2 | |
x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
Since retpoline capable compilers are widely available, make
CONFIG_RETPOLINE hard depend on the compiler capability.
Break the build when CONFIG_RETPOLINE is enabled and the compiler does not
support it. Emit an error message in that case:
"arch/x86/Makefile:226: *** You are building kernel with non-retpoline
compiler, please update your compiler.. Stop."
[dwmw: Fail the build with non-retpoline compiler]
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: <srinivas.eeda@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/cca0cb20-f9e2-4094-840b-fb0f8810cd34@default
Diffstat (limited to 'arch/x86/Makefile')
| -rw-r--r-- | arch/x86/Makefile | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 88398fdf8129..f5d7f4134524 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -220,9 +220,10 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables # Avoid indirect branches in kernel to deal with Spectre ifdef CONFIG_RETPOLINE -ifneq ($(RETPOLINE_CFLAGS),) - KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE +ifeq ($(RETPOLINE_CFLAGS),) + $(error You are building kernel with non-retpoline compiler, please update your compiler.) endif + KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) endif archscripts: scripts_basic |