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Message-ID: <8f3d86e4-f051-2cf8-d5ec-f1046632bbda@loongson.cn>
Date:   Thu, 14 Jul 2022 15:14:59 +0800
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Subject: Re: [PATCH] LoongArch: Fix missing fcsr in ptrace's fpr_set
Content-Language: en-US
To:     Conor.Dooley@microchip.com, chenhuacai@kernel.org,
        kernel@xen0n.name, oleg@redhat.com
Cc:     lixu@loongson.cn, loongarch@lists.linux.dev,
        linux-kernel@vger.kernel.org
References: <20220714062550.4934-1-huqi@loongson.cn>
 <6bc55cd5-bb6e-8d4a-79ec-4555c0b7765b@microchip.com>
From:   Qi Hu <huqi@loongson.cn>
In-Reply-To: <6bc55cd5-bb6e-8d4a-79ec-4555c0b7765b@microchip.com>
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On 2022/7/14 14:51, Conor.Dooley@microchip.com wrote:
> On 14/07/2022 07:25, Qi Hu wrote:
>> In file ptrace.c, function fpr_set does not copy fcsr data from ubuf
>> to kbuf. That's the reason why fcsr cannot be modified by ptrace.
>>
>> This patch fixs this problem and allows users using ptrace to modify
>> the fcsr.
>>
>> Signed-off-by: Qi Hu <huqi@loongson.cn>
>> Signed-off-by: Xu Li <lixu@loongson.cn>
> Hey Qi Hu,
>
> Why does this have Xu Li's SoB if they're neither the author nor listed
> as a Co-developed-by:?
>
> As submitter, your SoB should be last anyway.
> Thanks,
> Conor.
>
Ops. I realize using SoB here is incorrect. I will change it into 
Co-developed-by.

Thanks.

Qi.

>> ---
>>    arch/loongarch/kernel/ptrace.c | 12 +++++++-----
>>    1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
>> index e6ab87948e1d..dc2b82ea894c 100644
>> --- a/arch/loongarch/kernel/ptrace.c
>> +++ b/arch/loongarch/kernel/ptrace.c
>> @@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
>>    		   const void *kbuf, const void __user *ubuf)
>>    {
>>    	const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
>> -	const int fcc_end = fcc_start + sizeof(u64);
>> +	const int fcsr_start = fcc_start + sizeof(u64);
>>    	int err;
>>    
>>    	BUG_ON(count % sizeof(elf_fpreg_t));
>> @@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
>>    	if (err)
>>    		return err;
>>    
>> -	if (count > 0)
>> -		err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> -					  &target->thread.fpu.fcc,
>> -					  fcc_start, fcc_end);
>> +	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> +				  &target->thread.fpu.fcc, fcc_start,
>> +				  fcc_start + sizeof(u64));
>> +	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
>> +				  &target->thread.fpu.fcsr, fcsr_start,
>> +				  fcsr_start + sizeof(u32));
>>    
>>    	return err;
>>    }