linux-kernel - Re: [PATCH REBASE v4 12/14] mips: Replace arch specific way to determine 32bit task with generic version

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Message-ID: <17fa5d60-2417-70cb-36b0-203b30b27624@ghiti.fr>
Date:   Thu, 25 Jul 2019 08:09:11 +0200
From:   Alexandre Ghiti <alex@...ti.fr>
To:     Luis Chamberlain <mcgrof@...nel.org>
Cc:     Albert Ou <aou@...s.berkeley.edu>,
        Kees Cook <keescook@...omium.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Palmer Dabbelt <palmer@...ive.com>,
        Will Deacon <will.deacon@....com>,
        Russell King <linux@...linux.org.uk>,
        Ralf Baechle <ralf@...ux-mips.org>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Paul Burton <paul.burton@...s.com>,
        linux-riscv@...ts.infradead.org,
        Alexander Viro <viro@...iv.linux.org.uk>,
        James Hogan <jhogan@...nel.org>, linux-fsdevel@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-mips@...r.kernel.org, Christoph Hellwig <hch@....de>,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH REBASE v4 12/14] mips: Replace arch specific way to
 determine 32bit task with generic version

On 7/24/19 7:16 PM, Luis Chamberlain wrote:
> On Wed, Jul 24, 2019 at 01:58:48AM -0400, Alexandre Ghiti wrote:
>> Mips uses TASK_IS_32BIT_ADDR to determine if a task is 32bit, but
>> this define is mips specific and other arches do not have it: instead,
>> use !IS_ENABLED(CONFIG_64BIT) || is_compat_task() condition.
>>
>> Signed-off-by: Alexandre Ghiti <alex@...ti.fr>
>> Reviewed-by: Kees Cook <keescook@...omium.org>
>> ---
>>   arch/mips/mm/mmap.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
>> index faa5aa615389..d4eafbb82789 100644
>> --- a/arch/mips/mm/mmap.c
>> +++ b/arch/mips/mm/mmap.c
>> @@ -17,6 +17,7 @@
>>   #include <linux/sched/signal.h>
>>   #include <linux/sched/mm.h>
>>   #include <linux/sizes.h>
>> +#include <linux/compat.h>
>>   
>>   unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */
>>   EXPORT_SYMBOL(shm_align_mask);
>> @@ -191,7 +192,7 @@ static inline unsigned long brk_rnd(void)
>>   
>>   	rnd = rnd << PAGE_SHIFT;
>>   	/* 32MB for 32bit, 1GB for 64bit */
>> -	if (TASK_IS_32BIT_ADDR)
>> +	if (!IS_ENABLED(CONFIG_64BIT) || is_compat_task())
>>   		rnd = rnd & SZ_32M;
>>   	else
>>   		rnd = rnd & SZ_1G;
>> -- 
> Since there are at least two users why not just create an inline for
> this which describes what we are looking for and remove the comments?

Actually this is a preparatory patch, this will get merged with the 
generic version in the next patch.

Alex

>
>    Luis
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

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