Re: [PATCH] wifi: ath9k: Don't mark channelmap stack variable read-only in ath9k_mci_update_wlan_channels()

["Toke Høiland-Jørgensen" <toke@toke.dk>]

Kalle Valo <kvalo@kernel.org> writes:

> Toke Høiland-Jørgensen <toke@toke.dk> writes:
>
>> This partially reverts commit e161d4b60ae3a5356e07202e0bfedb5fad82c6aa.
>>
>> Turns out the channelmap variable is not actually read-only, it's modified
>> through the MCI_GPM_CLR_CHANNEL_BIT() macro further down in the function,
>> so making it read-only causes page faults when that code is hit.
>>
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=217183
>> Fixes: e161d4b60ae3 ("wifi: ath9k: Make arrays prof_prio and channelmap static const")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
>
> I guess the casting in MCI_GPM_CLR_CHANNEL_BIT() hide this and made it
> impossible for the compiler to detect it? A perfect example why I hate
> casting :)

Yup, exactly. I was also assuming the compiler would catch it, but yay, C! :/

Anyway, cf the bugzilla this was a pretty bad regression for 6.2, so
would be good to move this along reasonably quickly (although I guess we
just missed the -net PR for rc7)...

-Toke