From: "bibo,mao" <bibo.mao@intel.com>
To: linux-ia64@vger.kernel.org
Subject: Re: [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take
Date: Thu, 02 Nov 2006 07:52:39 +0000 [thread overview]
Message-ID: <4549A3C7.1050305@intel.com> (raw)
In-Reply-To: <454961EE.4070608@intel.com>
Chen, Kenneth W wrote:
> Mao, Bibo wrote on Wednesday, November 01, 2006 7:12 PM
>> @@ -463,7 +469,10 @@ void __kprobes arch_arm_kprobe(struct kp
>>
>> flush_icache_range((unsigned long)p->ainsn.insn,
>> (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
>> - memcpy((char *)arm_addr, &p->opcode, sizeof(kprobe_opcode_t));
>> + if (ATOMIC_UPDATE)
>> + kprobe_update_bundle((void *)arm_addr, (void *)&p->opcode);
>> + else
>> + memcpy((char *)arm_addr, &p->opcode, sizeof(kprobe_opcode_t));
>> flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
>> }
>
> Now comments on the code: why memcpy in the else statement? In the earlier
> part of the patch, you already reject kprobe address on slot 1 if CPU doesn't
> have 16-byte memory operation. Why do you allow memcpy here? Will the "else"
> condition ever be executed?
>
else means that current cpu does not support 16 byte atomic operation. If kprobe
address is on slot 0/2, then memcpy still can execute.
thanks
bibo,mao
next prev parent reply other threads:[~2006-11-02 7:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-02 3:11 [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take 2 bibo,mao
2006-11-02 3:39 ` Keith Owens
2006-11-02 5:04 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take bibo,mao
2006-11-02 6:51 ` bibo,mao
2006-11-02 7:17 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take 2 Keith Owens
2006-11-02 7:22 ` Keith Owens
2006-11-02 7:25 ` Keith Owens
2006-11-02 7:27 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take bibo,mao
2006-11-02 7:32 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take 2 Keith Owens
2006-11-02 7:38 ` Chen, Kenneth W
2006-11-02 7:45 ` Chen, Kenneth W
2006-11-02 7:52 ` bibo,mao [this message]
2006-11-02 8:17 ` Chen, Kenneth W
2006-11-02 8:56 ` Chen, Kenneth W
2006-11-02 9:05 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take bibo,mao
2006-11-02 9:22 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take 2 Chen, Kenneth W
2006-11-02 19:50 ` Chen, Kenneth W
2006-11-02 19:57 ` Luck, Tony
2006-11-02 20:29 ` Chen, Kenneth W
2006-11-03 1:25 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take bibo,mao
2006-11-03 1:55 ` [PATCH]IA64 trap code 16 bytes atomic copy on montecito, take 2 Chen, Kenneth W
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