[PATCH -tip v6 11/11] [RFC] kprobes/x86: Use text_poke_fixup() forjump optimization

From: Masami Hiramatsu
Date: Wed Nov 25 2009 - 11:57:15 EST


Use text_poke_fixup() for jump optimization instead of text_poke_smp().

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jim Keniston <jkenisto@xxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Anders Kaseorg <andersk@xxxxxxxxxxx>
Cc: Tim Abbott <tabbott@xxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
---

arch/x86/kernel/kprobes.c | 10 +++-------
1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index d865f8c..33e15cf 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -1376,12 +1376,8 @@ int __kprobes arch_optimize_kprobe(struct optimized_kprobe *op)
jmp_code[0] = RELATIVEJUMP_OPCODE;
*(s32 *)(&jmp_code[1]) = rel;

- /*
- * text_poke_smp doesn't support NMI/MCE code modifying.
- * However, since kprobes itself also doesn't support NMI/MCE
- * code probing, it's not a problem.
- */
- text_poke_smp(op->kp.addr, jmp_code, RELATIVEJUMP_SIZE);
+ text_poke_fixup(op->kp.addr, jmp_code, RELATIVEJUMP_SIZE,
+ op->optinsn.insn);
return 0;
}

@@ -1393,7 +1389,7 @@ void __kprobes arch_unoptimize_kprobe(struct optimized_kprobe *op)
/* Set int3 to first byte for kprobes */
buf[0] = BREAKPOINT_INSTRUCTION;
memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);
- text_poke_smp(op->kp.addr, buf, RELATIVEJUMP_SIZE);
+ text_poke_fixup(op->kp.addr, buf, RELATIVEJUMP_SIZE, op->optinsn.insn);
}

static int __kprobes setup_detour_execution(struct kprobe *p,


--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@xxxxxxxxxx
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