Commit-ID: bd0b90676c30fe640e7ead919b3e38846ac88ab7 Gitweb: http://git.kernel.org/tip/bd0b90676c30fe640e7ead919b3e38846ac88ab7 Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx> AuthorDate: Wed, 29 Mar 2017 13:56:56 +0900 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 12 Apr 2017 09:23:44 +0200 kprobes/x86: Fix kprobe-booster not to boost far call instructions Fix the kprobe-booster not to boost far call instruction, because a call may store the address in the single-step execution buffer to the stack, which should be modified after single stepping. Currently, this instruction will be filtered as not boostable in resume_execution(), so this is not a critical issue. Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: David S . Miller <davem@xxxxxxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ye Xiaolong <xiaolong.ye@xxxxxxxxx> Link: http://lkml.kernel.org/r/149076340615.22469.14066273186134229909.stgit@devbox Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/kprobes/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 993fa4f..9eae5a6 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -200,6 +200,8 @@ retry: return (opcode != 0x62 && opcode != 0x67); case 0x70: return 0; /* can't boost conditional jump */ + case 0x90: + return opcode != 0x9a; /* can't boost call far */ case 0xc0: /* can't boost software-interruptions */ return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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