Mark Rutland <mark.rutland@xxxxxxx> wrote:
> For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
> preference to ACCESS_ONCE(), and new code is expected to use one of the
> former. So far, there's been no reason to change most existing uses of
> ACCESS_ONCE(), as these aren't currently harmful.
>
> However, for some new features (e.g. KTSAN / Kernel Thread Sanitizer),
> it is necessary to instrument reads and writes separately, which is not
> possible with ACCESS_ONCE(). This distinction is critical to correct
> operation.
>
> It's possible to transform the bulk of kernel code using the Coccinelle
> script below. However, for some files (including the ath9k ar9002 mac
> driver), this mangles the formatting. As a preparatory step, this patch
> converts the driver to use {READ,WRITE}_ONCE() without said mangling.
>
> ----
> virtual patch
>
> @ depends on patch @
> expression E1, E2;
> @@
>
> - ACCESS_ONCE(E1) = E2
> + WRITE_ONCE(E1, E2)
>
> @ depends on patch @
> expression E;
> @@
>
> - ACCESS_ONCE(E)
> + READ_ONCE(E)
> ----
>
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: ath9k-devel@xxxxxxxxxxxxxxxx
> Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
> Cc: linux-wireless@xxxxxxxxxxxxxxx
> Cc: ath9k-devel@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
2 patches applied to ath-next branch of ath.git, thanks.
d5a3a76a9cb8 ath9k: ar9002_mac: kill off ACCESS_ONCE()
50f3818196f5 ath9k: ar9003_mac: kill off ACCESS_ONCE()
--
https://patchwork.kernel.org/patch/9489799/
Documentation about submitting wireless patches and checking status
from patchwork:
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
