[PATCH] ARM: Remove address checking for MMUless devices

[Linux regression tracking (Thorsten Leemhuis)]

On 12.06.24 03:25, Yanjun Yang wrote:
> Apologies for not CCing the relevant maintainers in my previous email.
> 
> On Tue, Jun 11, 2024 at 6:09 PM Yanjun Yang <yangyj.ee at gmail.com> wrote:
>>
>> Commit 169f9102f9198b ("ARM: 9350/1: fault:
>> Implement copy_from_kernel_nofault_allowed()") added the function to check
>> address before use. However, for devices without MMU, addr > TASK_SIZE
>> will always fail.  This patch move this function after the #ifdef
>> CONFIG_MMU statement.

What happened to this fix regression for a 6.9 regression? From here it
looks like it fell through the cracks, but I might be missing something.

>> Also reported at https://bugzilla.kernel.org/show_bug.cgi?id=218953

Side note: this afaics ideally should be:

 Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218953

Ciao, Thorsten

>> Signed-off-by: Yanjun Yang <yangyj.ee at gmail.com>
>> ---
>>  arch/arm/mm/fault.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
>> index 67c425341a95..ab01b51de559 100644
>> --- a/arch/arm/mm/fault.c
>> +++ b/arch/arm/mm/fault.c
>> @@ -25,6 +25,8 @@
>>
>>  #include "fault.h"
>>
>> +#ifdef CONFIG_MMU
>> +
>>  bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
>>  {
>>         unsigned long addr = (unsigned long)unsafe_src;
>> @@ -32,8 +34,6 @@ bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
>>         return addr >= TASK_SIZE && ULONG_MAX - addr >= size;
>>  }
>>
>> -#ifdef CONFIG_MMU
>> -
>>  /*
>>   * This is useful to dump out the page tables associated with
>>   * 'addr' in mm 'mm'.
>> --
>> 2.45.2
>>
>