Re: [PATCH v2] powerpc/uaccess: Implement unsafe_put_user() using 'asm goto'

[Christophe Leroy <christophe.leroy@c-s.fr>]

Le 16/04/2020 à 00:37, Segher Boessenkool a écrit :
> Hi!
> 
> On Wed, Apr 15, 2020 at 09:25:59AM +0000, Christophe Leroy wrote:
>> +#define __put_user_goto(x, ptr, label) \
>> +	__put_user_nocheck_goto((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label)
> 
> This line gets too long, can you break it up somehow?

This line has 86 chars.

powerpc arch tolerates lines with up to 90 chars, see 
arch/powerpc/tools/checkpatch.sh

> 
>> +#define __put_user_asm_goto(x, addr, label, op)			\
>> +	asm volatile goto(					\
>> +		"1:	" op "%U1%X1 %0,%1	# put_user\n"	\
>> +		EX_TABLE(1b, %l2)				\
>> +		:						\
>> +		: "r" (x), "m" (*addr)				\
>> +		:						\
>> +		: label)
> 
> Same "%Un" problem as in the other patch.  You could use "m<>" here,
> but maybe just dropping "%Un" is better.

Ok.

I kept it to be consistent with the other patch.

> 
>> +#ifdef __powerpc64__
>> +#define __put_user_asm2_goto(x, ptr, label)			\
>> +	__put_user_asm_goto(x, ptr, label, "std")
>> +#else /* __powerpc64__ */
>> +#define __put_user_asm2_goto(x, addr, label)			\
>> +	asm volatile goto(					\
>> +		"1:	stw%U1%X1 %0, %1\n"			\
>> +		"2:	stw%U1%X1 %L0, %L1\n"			\
>> +		EX_TABLE(1b, %l2)				\
>> +		EX_TABLE(2b, %l2)				\
>> +		:						\
>> +		: "r" (x), "m" (*addr)				\
>> +		:						\
>> +		: label)
>> +#endif /* __powerpc64__ */
> 
> Here, you should drop it for sure.

Done.

Christophe