Re: [PATCH v5 2/3] kprobes: copy ainsn after alloc aggr kprobe

From: Wang Nan
Date: Thu Aug 28 2014 - 07:09:15 EST


On 2014/8/28 17:39, Masami Hiramatsu wrote:
> (2014/08/27 22:02), Wang Nan wrote:
>> Copy old kprobe to newly alloced optimized_kprobe before
>> arch_prepare_optimized_kprobe(). Original kprove can brings more
>> information to optimizer.
>>
>> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
>> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
>> Cc: "David A. Long" <dave.long@xxxxxxxxxx>
>> Cc: Jon Medhurst <tixy@xxxxxxxxxx>
>> Cc: Taras Kondratiuk <taras.kondratiuk@xxxxxxxxxx>
>> Cc: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
>> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
>> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>
>> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
>> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
>> Cc: Will Deacon <will.deacon@xxxxxxx>
>> ---
>> kernel/kprobes.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
>> index 3995f54..33cf568 100644
>> --- a/kernel/kprobes.c
>> +++ b/kernel/kprobes.c
>> @@ -730,7 +730,12 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
>> return NULL;
>>
>> INIT_LIST_HEAD(&op->list);
>> - op->kp.addr = p->addr;
>
> Do not remove this, since copy_kprobe() doesn't copy kp.addr.
>
> static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p)
> {
> memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t));
> memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn));
> }
>
> Thank you,
>

It is my fault. I'll fix it in next version.

Thank you for your comment!

>> +
>> + /*
>> + * copy gives arch_prepare_optimized_kprobe
>> + * more information
>> + */
>> + copy_kprobe(p, &op->kp);
>> arch_prepare_optimized_kprobe(op);
>>
>> return &op->kp;
>>
>
>


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