Re: [PATCH v2] arch: s390: appldata: using strncpy() and strnlen() instead of sprintf()

[Chen Gang <gang.chen@asianux.com>]

On 05/29/2013 03:29 PM, Chen Gang wrote:
> On 05/29/2013 02:30 PM, Dan Carpenter wrote:
>> On Wed, May 29, 2013 at 09:28:43AM +0800, Chen Gang wrote:
>>
>>>> diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c
>>>> index bae0f40..27f200d 100644
>>>> --- a/arch/s390/appldata/appldata_base.c
>>>> +++ b/arch/s390/appldata/appldata_base.c
>>>> @@ -212,10 +212,9 @@ appldata_timer_handler(ctl_table *ctl, int write,
>>>>  		return 0;
>>>>  	}
>>>>  	if (!write) {
>>>> -		len = sprintf(buf, appldata_timer_active ? "1\n" : "0\n");
>>>> -		if (len > *lenp)
>>>> -			len = *lenp;
>>>> -		if (copy_to_user(buffer, buf, len))
>>>> +		if (copy_to_user(buffer,
>>>> +				 appldata_timer_active ? "1\n" : "0\n",
>>>> +				 min(2, *lenp))
>> I don't have a cross compiler set up, but this will generate a
>> warning, I think.  min_t() is needed.
> 
> Yes, it even can not pass compiling: need additional ')' for 'if'.
> 
> The new fix is below, (for pass compiling, also need fix the incorrect
> declaration, which I have already sent an individual patch for it).
> 

Excuse me, the diff v2 is word wrap, if really need it, please edit it.

If necessary, I will send the related patch for it.

Thanks.

> -----------------------------diff v2 begin------------------------------
> 
> diff --git a/arch/s390/appldata/appldata_base.c
> b/arch/s390/appldata/appldata_base.c
> index bae0f40..b0915b4 100644
> --- a/arch/s390/appldata/appldata_base.c
> +++ b/arch/s390/appldata/appldata_base.c
> @@ -212,10 +212,9 @@ appldata_timer_handler(ctl_table *ctl, int write,
>  		return 0;
>  	}
>  	if (!write) {
> -		len = sprintf(buf, appldata_timer_active ? "1\n" : "0\n");
> -		if (len > *lenp)
> -			len = *lenp;
> -		if (copy_to_user(buffer, buf, len))
> +		if (copy_to_user(buffer,
> +				 appldata_timer_active ? "1\n" : "0\n",
> +				 min_t(size_t, 2, *lenp)))
>  			return -EFAULT;
>  		goto out;
>  	}
> diff --git a/arch/s390/include/asm/pgtable.h
> b/arch/s390/include/asm/pgtable.h
> index 172209c..ed88890 100644
> --- a/arch/s390/include/asm/pgtable.h
> +++ b/arch/s390/include/asm/pgtable.h
> @@ -1348,7 +1348,7 @@ static inline pmd_t pmd_mkwrite(pmd_t pmd)
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> 
>  #define __HAVE_ARCH_PGTABLE_DEPOSIT
> -extern void pgtable_trans_huge_deposit(struct mm_struct *mm, , pmd_t *pmdp,
> +extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
>  				       pgtable_t pgtable);
> 
>  #define __HAVE_ARCH_PGTABLE_WITHDRAW
> 
> 
> -----------------------------diff v2 end--------------------------------
> 
> 
> For cross compiler, I use fedora 16/17, can yum update binutils-*
> to get many platform cross-compilers (s390, powerpc, arm, xtensa, ...).
> 
> 
> Thanks.
> 


-- 
Chen Gang

Asianux Corporation