3.16.68-rc1 review patch. If anyone has any objections, please let me know.
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From: Andy Lutomirski luto@kernel.org
commit c28454332fe0b65e22c3a2717e5bf05b5b47ca20 upstream.
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... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/x86/include/asm/jump_label.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- 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>