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[v2,0/3] gpiolib: cdev: tidy up kfifo handling

Message ID 20240529131953.195777-1-warthog618@gmail.com
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Series gpiolib: cdev: tidy up kfifo handling | expand

Message

Kent Gibson May 29, 2024, 1:19 p.m. UTC 
This series is a follow up to my recent kfifo initialisation fix[1].

Patch 1 adds calling INIT_KFIFO() on the event kfifo in order to induce
an oops if the kfifo is accessed prior to being allocated.  Not calling
INIT_KFIFO() could be considered an abuse of the kfifo API. I don't
recall, but it is possible that it was not being called as we also make
use of kfifo_initialized(), and the assumption was that it would return
true after the INIT_KFIFO() call. In fact it only returns true once
the kfifo has been allocated.

Patch 2 adds a helper to perform the allocation of the kfifo to reduce
code duplication.

Patch 3 tidies up the handling of kfifo_out() errors, making them
visible where they may currently be obscured.  These errors are not
expected to ever happen, so this should not produce any visible
difference, but if they do occur it will now be more obvious.

Cheers,
Kent.

Changes v1 -> v2:
 - add WARN() to patch 3.

Kent Gibson (3):
  gpiolib: cdev: Add INIT_KFIFO() for linereq events
  gpiolib: cdev: Refactor allocation of linereq events kfifo
  gpiolib: cdev: Cleanup kfifo_out() error handling

 drivers/gpio/gpiolib-cdev.c | 80 +++++++++++++++++++------------------
 1 file changed, 41 insertions(+), 39 deletions(-)

--
2.39.2

Comments

Bartosz Golaszewski May 30, 2024, 9:29 a.m. UTC | #1 
From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>


On Wed, 29 May 2024 21:19:50 +0800, Kent Gibson wrote:
> This series is a follow up to my recent kfifo initialisation fix[1].
> 
> Patch 1 adds calling INIT_KFIFO() on the event kfifo in order to induce
> an oops if the kfifo is accessed prior to being allocated.  Not calling
> INIT_KFIFO() could be considered an abuse of the kfifo API. I don't
> recall, but it is possible that it was not being called as we also make
> use of kfifo_initialized(), and the assumption was that it would return
> true after the INIT_KFIFO() call. In fact it only returns true once
> the kfifo has been allocated.
> 
> [...]

Applied, thanks!

[1/3] gpiolib: cdev: Add INIT_KFIFO() for linereq events
      commit: 35d848e7a1cbba2649ed98cf58e0cdc7ee560c7a
[2/3] gpiolib: cdev: Refactor allocation of linereq events kfifo
      commit: 4ce5ca654a761462a222164e96b8ab953b8cacab
[3/3] gpiolib: cdev: Cleanup kfifo_out() error handling
      commit: 2ba4746b418dcffadb3b135657fea8d3e62b4c30

Best regards,