From 0f363b250b15af0f218bb2876d101fe5cd413f8b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 16 Dec 2014 11:46:14 +0100 Subject: [PATCH] x86: Fix off-by-one in instruction decoder Stephane reported that the PEBS fixup was broken by the recent commit to the instruction decoder. The thing had an off-by-one which resulted in not being able to decode the last instruction and always bail. Reported-by: Stephane Eranian Fixes: 6ba48ff46f76 ("x86: Remove arbitrary instruction size limit in instruction decoder") Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org # 3.18 Cc: Cc: Jiri Olsa Cc: Liang Kan Cc: Arnaldo Carvalho de Melo Cc: Dave Hansen Cc: Jim Keniston Cc: Linus Torvalds Cc: Masami Hiramatsu Link: http://lkml.kernel.org/r/20141216104614.GV3337@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- arch/x86/lib/insn.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c index 2480978b31cc..1313ae6b478b 100644 --- a/arch/x86/lib/insn.c +++ b/arch/x86/lib/insn.c @@ -28,7 +28,7 @@ /* Verify next sizeof(t) bytes can be on the same instruction */ #define validate_next(t, insn, n) \ - ((insn)->next_byte + sizeof(t) + n < (insn)->end_kaddr) + ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) #define __get_next(t, insn) \ ({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; }) -- 2.20.1