This is a note to let you know that I've just added the patch titled
x86/kprobes: Identify far indirect JMP correctly
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-kprobes-identify-far-indirect-jmp-correctly.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Wed Jul 5 08:47:51 2023
From: Li Huafei <lihuafei1@xxxxxxxxxx>
Date: Wed, 5 Jul 2023 14:46:48 +0800
Subject: x86/kprobes: Identify far indirect JMP correctly
To: <stable@xxxxxxxxxxxxxxx>
Cc: <gregkh@xxxxxxxxxxxxxxxxxxx>, <mhiramat@xxxxxxxxxx>, <tglx@xxxxxxxxxxxxx>, <mingo@xxxxxxxxxx>, <bp@xxxxxxxxx>, <x86@xxxxxxxxxx>, <hpa@xxxxxxxxx>, <sashal@xxxxxxxxxx>, <peterz@xxxxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>, <xukuohai@xxxxxxxxxx>, <natechancellor@xxxxxxxxx>, <ndesaulniers@xxxxxxxxxx>, <rostedt@xxxxxxxxxxx>, <weiyongjun1@xxxxxxxxxx>, <gustavoars@xxxxxxxxxx>, <namit@xxxxxxxxxx>, <laijs@xxxxxxxxxxxxxxxxx>, <clang-built-linux@xxxxxxxxxxxxxxxx>, <lihuafei1@xxxxxxxxxx>
Message-ID: <20230705064653.226811-5-lihuafei1@xxxxxxxxxx>
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
[ Upstream commit a194acd316f93f3435a64de3b37dca2b5a77b338 ]
Since Grp5 far indirect JMP is FF "mod 101 r/m", it should be
(modrm & 0x38) == 0x28, and near indirect JMP is also 0x38 == 0x20.
So we can mask modrm with 0x30 and check 0x20.
This is actually what the original code does, it also doesn't care
the last bit. So the result code is same.
Thus, I think this is just a cosmetic cleanup.
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/161469873475.49483.13257083019966335137.stgit@devnote2
Signed-off-by: Li Huafei <lihuafei1@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/kprobes/core.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -478,8 +478,7 @@ static void set_resume_flags(struct kpro
p->ainsn.is_call = 1;
p->ainsn.is_abs_ip = 1;
break;
- } else if (((opcode & 0x31) == 0x20) ||
- ((opcode & 0x31) == 0x21)) {
+ } else if ((opcode & 0x30) == 0x20) {
/*
* jmp near and far, absolute indirect
* ip is correct.
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-5.10/x86-kprobes-update-kcb-status-flag-after-singlestepping.patch
queue-5.10/x86-kprobes-fix-to-identify-indirect-jmp-and-others-using-range-case.patch
queue-5.10/x86-kprobes-fix-jng-jnle-emulation.patch
queue-5.10/x86-kprobes-retrieve-correct-opcode-for-group-instruction.patch
queue-5.10/x86-kprobes-use-int3-instead-of-debug-trap-for-single-step.patch
queue-5.10/x86-kprobes-do-not-decode-opcode-in-resume_execution.patch
queue-5.10/x86-kprobes-identify-far-indirect-jmp-correctly.patch
queue-5.10/kprobes-x86-fix-fall-through-warnings-for-clang.patch
queue-5.10/x86-kprobes-move-inline-to-the-beginning-of-the-kprobe_is_ss-declaration.patch
