Re: [PATCH net] wifi: ath12k: fix build vs old compiler

[Kalle Valo <kvalo@kernel.org>]

Jeff Johnson <quic_jjohnson@quicinc.com> writes:

> On 7/16/2024 4:06 AM, Paolo Abeni wrote:
>
>> gcc 11.4.1-3 warns about memcpy() with overlapping pointers:
>> 
>> drivers/net/wireless/ath/ath12k/wow.c: In function
>> ‘ath12k_wow_convert_8023_to_80211.constprop’:
>> ./include/linux/fortify-string.h:114:33: error: ‘__builtin_memcpy’
>> accessing 18446744073709551611 or more bytes at offsets 0 and 0
>> overlaps 9223372036854775799 bytes at offset -9223372036854775804
>> [-Werror=restrict]
>>   114 | #define __underlying_memcpy     __builtin_memcpy
>>       |                                 ^
>> ./include/linux/fortify-string.h:637:9: note: in expansion of macro
>> ‘__underlying_memcpy’
>>   637 |         __underlying_##op(p, q, __fortify_size);                        \
>>       |         ^~~~~~~~~~~~~
>> ./include/linux/fortify-string.h:682:26: note: in expansion of macro
>> ‘__fortify_memcpy_chk’
>>   682 | #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
>>       |                          ^~~~~~~~~~~~~~~~~~~~
>> drivers/net/wireless/ath/ath12k/wow.c:190:25: note: in expansion of macro ‘memcpy’
>>   190 |                         memcpy(pat, eth_pat, eth_pat_len);
>>       |                         ^~~~~~
>> ./include/linux/fortify-string.h:114:33: error: ‘__builtin_memcpy’
>> accessing 18446744073709551605 or more bytes at offsets 0 and 0
>> overlaps 9223372036854775787 bytes at offset -9223372036854775798
>> [-Werror=restrict]
>>   114 | #define __underlying_memcpy     __builtin_memcpy
>>       |                                 ^
>> ./include/linux/fortify-string.h:637:9: note: in expansion of macro
>> ‘__underlying_memcpy’
>>   637 |         __underlying_##op(p, q, __fortify_size);                        \
>>       |         ^~~~~~~~~~~~~
>> ./include/linux/fortify-string.h:682:26: note: in expansion of macro
>> ‘__fortify_memcpy_chk’
>>   682 | #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
>>       |                          ^~~~~~~~~~~~~~~~~~~~
>> drivers/net/wireless/ath/ath12k/wow.c:232:25: note: in expansion of macro ‘memcpy’
>>   232 |                         memcpy(pat, eth_pat, eth_pat_len);
>>       |                         ^~~~~~
>> 
>> The sum of size_t operands can overflow SIZE_MAX, triggering the
>> warning.
>> Address the issue using the suitable helper.
>> 
>> Fixes: 4a3c212eee0e ("wifi: ath12k: add basic WoW functionalities")
>> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
>> ---
>> Only built tested. Sending directly to net to reduce the RTT, but no
>> objections to go through the WiFi tree first
>
> Since Kalle is on holiday please go ahead and take this via net.
> This looks nicer than Kalle's version :)

Indeed, this is nicer. Thanks Paolo!

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