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Subject: Re: [PATCH v9 2/4] LoongArch: Add kprobe support
To:     Huacai Chen <chenhuacai@kernel.org>
References: <1670506868-15771-1-git-send-email-yangtiezhu@loongson.cn>
 <1670506868-15771-3-git-send-email-yangtiezhu@loongson.cn>
 <CAAhV-H54yruHAe7ey8L9hHPonryEWEd8nt-iS6s7-odrDdrutw@mail.gmail.com>
Cc:     WANG Xuerui <kernel@xen0n.name>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        loongarch@lists.linux.dev, linux-kernel@vger.kernel.org
From:   Tiezhu Yang <yangtiezhu@loongson.cn>
Message-ID: <37bc5ab5-ced8-cae9-9025-180154af0b11@loongson.cn>
Date:   Fri, 9 Dec 2022 15:02:15 +0800
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On 12/09/2022 10:22 AM, Huacai Chen wrote:
>   cas
>
> On Thu, Dec 8, 2022 at 9:41 PM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>>
>> Kprobes allows you to trap at almost any kernel address and
>> execute a callback function, this commit adds kprobe support
>> for LoongArch.

...

>> +       case KPROBE_HIT_ACTIVE:
>> +       case KPROBE_HIT_SSDONE:
>> +               /*
>> +                * In case the user-specified fault handler returned
>> +                * zero, try to fix up.
>> +                */
>> +               if (fixup_exception(regs))
>> +                       return true;
> Does here need to enable preemption too?
>

No need, because in this two case, after call fixup_exception() or
do_page_fault(), the original process will continue, preemption will
be enabled in the original process.

Thanks,
Tiezhu