Messages in this thread Patch in this message | | | Date | Tue, 24 Nov 2015 01:35:58 -0800 | From | tip-bot for Andy Lutomirski <> | Subject | [tip:x86/asm] x86/asm: Error out if asm/ jump_label.h is included inappropriately |
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Commit-ID: c28454332fe0b65e22c3a2717e5bf05b5b47ca20 Gitweb: http://git.kernel.org/tip/c28454332fe0b65e22c3a2717e5bf05b5b47ca20 Author: Andy Lutomirski <luto@kernel.org> AuthorDate: Thu, 12 Nov 2015 12:59:02 -0800 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 24 Nov 2015 09:56:43 +0100
x86/asm: Error out if asm/jump_label.h is included inappropriately
Rather than potentially generating incorrect code on a non-HAVE_JUMP_LABEL kernel if someone includes asm/jump_label.h, error out.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/99407f0ac7fa3ab03a3d31ce076d47b5c2f44795.1447361906.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/include/asm/jump_label.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 5daeca3..96872dc 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -1,6 +1,19 @@ #ifndef _ASM_X86_JUMP_LABEL_H #define _ASM_X86_JUMP_LABEL_H +#ifndef HAVE_JUMP_LABEL +/* + * For better or for worse, if jump labels (the gcc extension) are missing, + * then the entire static branch patching infrastructure is compiled out. + * If that happens, the code in here will malfunction. Raise a compiler + * error instead. + * + * In theory, jump labels and the static branch patching infrastructure + * could be decoupled to fix this. + */ +#error asm/jump_label.h included on a non-jump-label kernel +#endif + #ifndef __ASSEMBLY__ #include <linux/stringify.h>
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