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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-03-03 00:25:34 +0900 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-03-23 16:07:56 +0100 |
| commit | a194acd316f93f3435a64de3b37dca2b5a77b338 (patch) | |
| tree | ff92b6594232ba0d5695aa49bb3d6487d879cda8 /arch/x86/kernel/kprobes/core.c | |
| parent | d60ad3d46f1d04a282c56159f1deb675c12733fd (diff) | |
| download | linux-a194acd316f93f3435a64de3b37dca2b5a77b338.tar.bz2 | |
x86/kprobes: Identify far indirect JMP correctly
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@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/161469873475.49483.13257083019966335137.stgit@devnote2
Diffstat (limited to 'arch/x86/kernel/kprobes/core.c')
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 9b31790a0b0a..f6ec57fa8e5a 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -467,8 +467,7 @@ static void set_resume_flags(struct kprobe *p, struct insn *insn) 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. |