| From | Sasha Levin <> | Subject | [PATCH AUTOSEL for 4.4 080/115] kprobes/x86: Fix kprobe-booster not to boost far call instructions | Date | Sat, 3 Mar 2018 22:31:37 +0000 |
| |
From: Masami Hiramatsu <mhiramat@kernel.org>
[ Upstream commit bd0b90676c30fe640e7ead919b3e38846ac88ab7 ]
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@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David S . Miller <davem@davemloft.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ye Xiaolong <xiaolong.ye@intel.com> Link: http://lkml.kernel.org/r/149076340615.22469.14066273186134229909.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> --- 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 99d293ea2b49..5d11d01f75de 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -196,6 +196,8 @@ 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; -- 2.14.1
|