linux-kernel - [PATCH 3/8] gpiolib: convert the type of hwnum to unsigned int in gpiochip_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191127133510.10614-4-brgl@bgdev.pl>
Date:   Wed, 27 Nov 2019 14:35:05 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Kent Gibson <warthog618@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: [PATCH 3/8] gpiolib: convert the type of hwnum to unsigned int in gpiochip_get_desc()

From: Bartosz Golaszewski <bgolaszewski@...libre.com>

gpiochip_get_desc() takes a u16 hwnum, but it turns out most users don't
respect that and usually pass an unsigned int. Since implicit casting to
a smaller type is dangerous - let's change the type of hwnum to unsigned
int in gpiochip_get_desc() and in gpiochip_request_own_desc() where the
size of hwnum is not respected either and who's a user of the former.

This is safe as we then check the hwnum against the number of lines
before proceeding in gpiochip_get_desc().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>
---
 drivers/gpio/gpiolib.c      | 5 +++--
 drivers/gpio/gpiolib.h      | 3 ++-
 include/linux/gpio/driver.h | 3 ++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 72211407469f..b3ffb079e323 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -140,7 +140,7 @@ EXPORT_SYMBOL_GPL(gpio_to_desc);
  * in the given chip for the specified hardware number.
  */
 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
-				    u16 hwnum)
+				    unsigned int hwnum)
 {
 	struct gpio_device *gdev = chip->gpiodev;
 
@@ -2990,7 +2990,8 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested);
  * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
  * code on failure.
  */
-struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
+struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip,
+					    unsigned int hwnum,
 					    const char *label,
 					    enum gpio_lookup_flags lflags,
 					    enum gpiod_flags dflags)
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index ca9bc1e4803c..a1cbeabadc69 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -78,7 +78,8 @@ struct gpio_array {
 	unsigned long		invert_mask[];
 };
 
-struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
+struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
+				    unsigned int hwnum);
 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
 				  unsigned int array_size,
 				  struct gpio_desc **desc_array,
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index e2480ef94c55..4f032de10bae 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -715,7 +715,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 
 #endif /* CONFIG_PINCTRL */
 
-struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
+struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip,
+					    unsigned int hwnum,
 					    const char *label,
 					    enum gpio_lookup_flags lflags,
 					    enum gpiod_flags dflags);
-- 
2.23.0