Subject: Re: [PATCH v5 3/4] arm64: mm: support ARCH_MMAP_RND_BITS.
To: Arnd Bergmann <arnd@arndb.de>, Jon Hunter <jonathanh@nvidia.com>
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From: Daniel Cashman <dcashman@android.com>
Message-ID: <5665CF5A.1090207@android.com>
Date: Mon, 7 Dec 2015 10:26:34 -0800
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On 12/07/2015 03:13 AM, Arnd Bergmann wrote:
> On Monday 07 December 2015 10:26:16 Jon Hunter wrote:
>>
>> diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
>> index af461b935137..e59a75a308bc 100644
>> --- a/arch/arm64/mm/mmap.c
>> +++ b/arch/arm64/mm/mmap.c
>> @@ -51,7 +51,7 @@ unsigned long arch_mmap_rnd(void)
>>  {
>>         unsigned long rnd;
>>  
>> -ifdef CONFIG_COMPAT
>> +#ifdef CONFIG_COMPAT

Thank you Jon.  This ought to persuade me to do a final build against
the final patch, rather than the ugly porting I had been doing.  I'll
include this in v6. (how embarassing =/)

>>         if (test_thread_flag(TIF_32BIT))
>>                 rnd = (unsigned long)get_random_int() % (1 << mmap_rnd_compat_bits);
>>         else
>>
>> Cheers
>>
> 
> Ideally we'd remove the #ifdef around the mmap_rnd_compat_bits declaration
> and change this code to use
> 
> 	if (IS_ENABLED(CONFIG_COMPAT) && test_thread_flag(TIF_32BIT))
> 
> 	Arnd

That would result in "undefined reference to mmap_rnd_compat_bits" in
the not-defined case, no?

Thank You,
Dan
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