From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

While reworking the locking in GPIOLIB I realized that locking the
descriptor with users still calling gpiochip_is_requested() will still
be buggy as it returns a pointer to a string that can be freed whenever
the descriptor is released. Let's provide a safer alternative in the
form of a function that returns a copy of the label.

Use it in all drivers and remove gpiochip_is_requested().

I plan to provide this series in an immutable branch for the pinctrl and
baytrail trees to pull.

v2 -> v3:
- rename a local variable cpy -> copy
- use unsigned int to loop over GPIO lines
- use an unscoped guard in patch 10/10 instead of the scoped variant

v1 -> v2:
- use DEFINE_CLASS() to register a destructor for making sure that the
  duplicated label doesn't leak out of the for_each loops even with
  break;

Bartosz Golaszewski (10):
  gpiolib: provide gpiochip_dup_line_label()
  gpio: wm831x: use gpiochip_dup_line_label()
  gpio: wm8994: use gpiochip_dup_line_label()
  gpio: stmpe: use gpiochip_dup_line_label()
  pinctrl: abx500: use gpiochip_dup_line_label()
  pinctrl: nomadik: use gpiochip_dup_line_label()
  pinctrl: baytrail: use gpiochip_dup_line_label()
  pinctrl: sppctl: use gpiochip_dup_line_label()
  gpiolib: use gpiochip_dup_line_label() in for_each helpers
  gpiolib: remove gpiochip_is_requested()

 drivers/gpio/gpio-stmpe.c                 |  6 +++-
 drivers/gpio/gpio-wm831x.c                | 14 +++++---
 drivers/gpio/gpio-wm8994.c                | 13 +++++---
 drivers/gpio/gpiolib.c                    | 35 ++++++++++++--------
 drivers/pinctrl/intel/pinctrl-baytrail.c  | 11 ++++---
 drivers/pinctrl/nomadik/pinctrl-abx500.c  |  9 ++++--
 drivers/pinctrl/nomadik/pinctrl-nomadik.c |  6 +++-
 drivers/pinctrl/sunplus/sppctl.c          | 10 +++---
 include/linux/gpio/driver.h               | 39 +++++++++++++++++------
 9 files changed, 96 insertions(+), 47 deletions(-)

-- 
2.40.1

On Mon, Dec 4, 2023 at 10:35 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> While reworking the locking in GPIOLIB I realized that locking the
> descriptor with users still calling gpiochip_is_requested() will still
> be buggy as it returns a pointer to a string that can be freed whenever
> the descriptor is released. Let's provide a safer alternative in the
> form of a function that returns a copy of the label.
>
> Use it in all drivers and remove gpiochip_is_requested().

The series:
Acked-by: Linus Walleij <linus.walleij@linaro.org>

> I plan to provide this series in an immutable branch for the pinctrl and
> baytrail trees to pull.

Nice! I'll pull it.

Yours,
Linus Walleij