x86/kprobes: Retrieve correct opcode for group instruction

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Since the opcodes start from 0xff are group5 instruction group which is
not 2 bytes opcode but the extended opcode determined by the MOD/RM byte.

The commit abd82e533d ("x86/kprobes: Do not decode opcode in resume_execution()")
used insn->opcode.bytes[1], but that is not correct. We have to refer
the insn->modrm.bytes[1] instead.

Fixes: abd82e533d ("x86/kprobes: Do not decode opcode in resume_execution()")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/161469872400.49483.18214724458034233166.stgit@devnote2

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Masami Hiramatsu 2021-03-03 00:25:24 +09:00 • committed by Peter Zijlstra

parent 0705ef64d1

commit d60ad3d46f

1 changed files with 5 additions and 1 deletions

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arch/x86/kernel/kprobes/core.c

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