From 01be50a308be466e122c3a8b3d535f1b673ecbd2 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 27 Nov 2009 15:04:58 +0000 Subject: x86/alternatives: Check replacementlen <= instrlen at build time Having run into the run-(boot-)time check a couple of times lately, I finally took time to find a build-time check so that one doesn't need to analyze the register/stack dump and resolve this (through manual lookup in vmlinux) to the offending construct. The assembler will emit a message like "Error: value of too large for field of 1 bytes at ", which while not pointing out the source location still makes analysis quite a bit easier. Signed-off-by: Jan Beulich LKML-Reference: <4B0FF8AA0200007800022703@vpn.id2.novell.com> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/alternative.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/include/asm/alternative.h') diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index c240efc74e00..69b74a7b877f 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -84,6 +84,7 @@ static inline void alternatives_smp_switch(int smp) {} " .byte " __stringify(feature) "\n" /* feature bit */ \ " .byte 662b-661b\n" /* sourcelen */ \ " .byte 664f-663f\n" /* replacementlen */ \ + " .byte 0xff + (664f-663f) - (662b-661b)\n" /* rlen <= slen */ \ ".previous\n" \ ".section .altinstr_replacement, \"ax\"\n" \ "663:\n\t" newinstr "\n664:\n" /* replacement */ \ -- cgit v1.2.3