Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH v3 3/5] x86/asm: Error out if asm/jump_label.h is included inappropriately | Date | Thu, 12 Nov 2015 12:59:02 -0800 |
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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> --- 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 5daeca3d0f9e..96872dc96597 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> -- 2.5.0
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