diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-11 00:01:00 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-11 00:01:00 +0300 |
commit | cfb4be1a61200fbbd29f2699b11899789855bbe4 (patch) | |
tree | 046c7604ddce9b2e517211a13e6007c062bd98d8 /drivers/gpio/gpiolib.h | |
parent | f4345f05c0dfc73c617e66f3b809edb8ddd41075 (diff) | |
parent | ee0166b637a5e376118e9659e5b4148080f1d27e (diff) | |
download | linux-cfb4be1a61200fbbd29f2699b11899789855bbe4.tar.xz |
Merge tag 'gpio-fixes-for-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
"Some last-minute fixes for this release from the GPIO subsystem.
The first two address a regression in performance reported to me after
the conversion to using SRCU in GPIOLIB that was merged during the
v6.9 merge window. The second patch is not technically a fix but since
after the first one we no longer need to use a per-descriptor SRCU
struct, I think it's worth to simplify the code before it gets
released on Sunday.
The next two commits fix two memory issues: one use-after-free bug and
one instance of possibly leaking kernel stack memory to user-space.
Summary:
- fix a performance regression in GPIO requesting and releasing after
the conversion to SRCU
- fix a use-after-free bug due to a race-condition
- fix leaking stack memory to user-space in a GPIO uABI corner case"
* tag 'gpio-fixes-for-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpiolib: cdev: fix uninitialised kfifo
gpiolib: cdev: Fix use after free in lineinfo_changed_notify
gpiolib: use a single SRCU struct for all GPIO descriptors
gpiolib: fix the speed of descriptor label setting with SRCU
Diffstat (limited to 'drivers/gpio/gpiolib.h')
-rw-r--r-- | drivers/gpio/gpiolib.h | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index f67d5991ab1c..8e0e211ebf08 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -31,6 +31,7 @@ * @chip: pointer to the corresponding gpiochip, holding static * data for this device * @descs: array of ngpio descriptors. + * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users * @ngpio: the number of GPIO lines on this GPIO device, equal to the size * of the @descs array. * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep @@ -61,6 +62,7 @@ struct gpio_device { struct module *owner; struct gpio_chip __rcu *chip; struct gpio_desc *descs; + struct srcu_struct desc_srcu; int base; u16 ngpio; bool can_sleep; @@ -137,6 +139,11 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); +struct gpio_desc_label { + struct rcu_head rh; + char str[]; +}; + /** * struct gpio_desc - Opaque descriptor for a GPIO * @@ -145,7 +152,6 @@ void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); * @label: Name of the consumer * @name: Line name * @hog: Pointer to the device node that hogs this line (if any) - * @srcu: SRCU struct protecting the label pointer. * * These are obtained using gpiod_get() and are preferable to the old * integer-based handles. @@ -177,13 +183,12 @@ struct gpio_desc { #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ /* Connection label */ - const char __rcu *label; + struct gpio_desc_label __rcu *label; /* Name of the GPIO */ const char *name; #ifdef CONFIG_OF_DYNAMIC struct device_node *hog; #endif - struct srcu_struct srcu; }; #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) @@ -251,7 +256,7 @@ static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) #define gpiod_err(desc, fmt, ...) \ do { \ - scoped_guard(srcu, &desc->srcu) { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ } \ @@ -259,7 +264,7 @@ do { \ #define gpiod_warn(desc, fmt, ...) \ do { \ - scoped_guard(srcu, &desc->srcu) { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ } \ @@ -267,7 +272,7 @@ do { \ #define gpiod_dbg(desc, fmt, ...) \ do { \ - scoped_guard(srcu, &desc->srcu) { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ } \ |