| From b8b9ce4b5aec8de9e23cabb0a26b78641f9ab1d6 Mon Sep 17 00:00:00 2001 |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Sun, 14 Jan 2018 22:13:29 +0100 |
| Subject: x86/retpoline: Remove compile time warning |
| |
| From: Thomas Gleixner <tglx@linutronix.de> |
| |
| commit b8b9ce4b5aec8de9e23cabb0a26b78641f9ab1d6 upstream. |
| |
| Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler |
| does not have retpoline support. Linus rationale for this is: |
| |
| It's wrong because it will just make people turn off RETPOLINE, and the |
| asm updates - and return stack clearing - that are independent of the |
| compiler are likely the most important parts because they are likely the |
| ones easiest to target. |
| |
| And it's annoying because most people won't be able to do anything about |
| it. The number of people building their own compiler? Very small. So if |
| their distro hasn't got a compiler yet (and pretty much nobody does), the |
| warning is just annoying crap. |
| |
| It is already properly reported as part of the sysfs interface. The |
| compile-time warning only encourages bad things. |
| |
| Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") |
| Requested-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Cc: David Woodhouse <dwmw@amazon.co.uk> |
| Cc: Peter Zijlstra (Intel) <peterz@infradead.org> |
| Cc: gnomes@lxorguk.ukuu.org.uk |
| Cc: Rik van Riel <riel@redhat.com> |
| Cc: Andi Kleen <ak@linux.intel.com> |
| Cc: Josh Poimboeuf <jpoimboe@redhat.com> |
| Cc: thomas.lendacky@amd.com |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Jiri Kosina <jikos@kernel.org> |
| Cc: Andy Lutomirski <luto@amacapital.net> |
| Cc: Dave Hansen <dave.hansen@intel.com> |
| Cc: Kees Cook <keescook@google.com> |
| Cc: Tim Chen <tim.c.chen@linux.intel.com> |
| Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> |
| Link: https://lkml.kernel.org/r/CA+55aFzWgquv4i6Mab6bASqYXg3ErV3XDFEYf=GEcCDQg5uAtw@mail.gmail.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/Makefile | 2 -- |
| 1 file changed, 2 deletions(-) |
| |
| --- a/arch/x86/Makefile |
| +++ b/arch/x86/Makefile |
| @@ -187,8 +187,6 @@ ifdef CONFIG_RETPOLINE |
| RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register) |
| ifneq ($(RETPOLINE_CFLAGS),) |
| KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE |
| - else |
| - $(warning CONFIG_RETPOLINE=y, but not supported by the compiler. Toolchain update recommended.) |
| endif |
| endif |
| |
