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gpiolib: cdev: replace locking wrappers for gpio_device with guards

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Replace the wrapping functions that inhibit removal of the gpio chip
with equivalent guards.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Kent Gibson 2023-12-21 09:20:40 +08:00 committed by Bartosz Golaszewski
parent 32d8e3b645
commit 20bddcb40b
1 changed files with 47 additions and 158 deletions
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205
drivers/gpio/gpiolib-cdev.c
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@ -24,6 +24,7 @@
#include <linux/pinctrl/consumer.h> #include <linux/pinctrl/consumer.h>
#include <linux/poll.h> #include <linux/poll.h>
#include <linux/rbtree.h> #include <linux/rbtree.h>
#include <linux/rwsem.h>
#include <linux/seq_file.h> #include <linux/seq_file.h>
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/timekeeping.h> #include <linux/timekeeping.h>
@ -65,45 +66,6 @@ typedef long (*ioctl_fn)(struct file *, unsigned int, unsigned long);
typedef ssize_t (*read_fn)(struct file *, char __user *, typedef ssize_t (*read_fn)(struct file *, char __user *,
size_t count, loff_t *); size_t count, loff_t *);
static __poll_t call_poll_locked(struct file *file,
struct poll_table_struct *wait,
struct gpio_device *gdev, poll_fn func)
{
__poll_t ret;
down_read(&gdev->sem);
ret = func(file, wait);
up_read(&gdev->sem);
return ret;
}
static long call_ioctl_locked(struct file *file, unsigned int cmd,
unsigned long arg, struct gpio_device *gdev,
ioctl_fn func)
{
long ret;
down_read(&gdev->sem);
ret = func(file, cmd, arg);
up_read(&gdev->sem);
return ret;
}
static ssize_t call_read_locked(struct file *file, char __user *buf,
size_t count, loff_t *f_ps,
struct gpio_device *gdev, read_fn func)
{
ssize_t ret;
down_read(&gdev->sem);
ret = func(file, buf, count, f_ps);
up_read(&gdev->sem);
return ret;
}
/* /*
* GPIO line handle management * GPIO line handle management
*/ */
@ -238,8 +200,8 @@ static long linehandle_set_config(struct linehandle_state *lh,
return 0; return 0;
} }
static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd, static long linehandle_ioctl(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
{ {
struct linehandle_state *lh = file->private_data; struct linehandle_state *lh = file->private_data;
void __user *ip = (void __user *)arg; void __user *ip = (void __user *)arg;
@ -248,6 +210,8 @@ static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd,
unsigned int i; unsigned int i;
int ret; int ret;
guard(rwsem_read)(&lh->gdev->sem);
if (!lh->gdev->chip) if (!lh->gdev->chip)
return -ENODEV; return -ENODEV;
@ -297,15 +261,6 @@ static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd,
} }
} }
static long linehandle_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct linehandle_state *lh = file->private_data;
return call_ioctl_locked(file, cmd, arg, lh->gdev,
linehandle_ioctl_unlocked);
}
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT
static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, static long linehandle_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
@ -1564,12 +1519,14 @@ static long linereq_set_config(struct linereq *lr, void __user *ip)
return 0; return 0;
} }
static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd, static long linereq_ioctl(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
{ {
struct linereq *lr = file->private_data; struct linereq *lr = file->private_data;
void __user *ip = (void __user *)arg; void __user *ip = (void __user *)arg;
guard(rwsem_read)(&lr->gdev->sem);
if (!lr->gdev->chip) if (!lr->gdev->chip)
return -ENODEV; return -ENODEV;
@ -1585,15 +1542,6 @@ static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd,
} }
} }
static long linereq_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct linereq *lr = file->private_data;
return call_ioctl_locked(file, cmd, arg, lr->gdev,
linereq_ioctl_unlocked);
}
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT
static long linereq_ioctl_compat(struct file *file, unsigned int cmd, static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
@ -1602,12 +1550,14 @@ static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
} }
#endif #endif
static __poll_t linereq_poll_unlocked(struct file *file, static __poll_t linereq_poll(struct file *file,
struct poll_table_struct *wait) struct poll_table_struct *wait)
{ {
struct linereq *lr = file->private_data; struct linereq *lr = file->private_data;
__poll_t events = 0; __poll_t events = 0;
guard(rwsem_read)(&lr->gdev->sem);
if (!lr->gdev->chip) if (!lr->gdev->chip)
return EPOLLHUP | EPOLLERR; return EPOLLHUP | EPOLLERR;
@ -1620,22 +1570,16 @@ static __poll_t linereq_poll_unlocked(struct file *file,
return events; return events;
} }
static __poll_t linereq_poll(struct file *file, static ssize_t linereq_read(struct file *file, char __user *buf,
struct poll_table_struct *wait) size_t count, loff_t *f_ps)
{
struct linereq *lr = file->private_data;
return call_poll_locked(file, wait, lr->gdev, linereq_poll_unlocked);
}
static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
size_t count, loff_t *f_ps)
{ {
struct linereq *lr = file->private_data; struct linereq *lr = file->private_data;
struct gpio_v2_line_event le; struct gpio_v2_line_event le;
ssize_t bytes_read = 0; ssize_t bytes_read = 0;
int ret; int ret;
guard(rwsem_read)(&lr->gdev->sem);
if (!lr->gdev->chip) if (!lr->gdev->chip)
return -ENODEV; return -ENODEV;
@ -1677,15 +1621,6 @@ static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
return bytes_read; return bytes_read;
} }
static ssize_t linereq_read(struct file *file, char __user *buf,
size_t count, loff_t *f_ps)
{
struct linereq *lr = file->private_data;
return call_read_locked(file, buf, count, f_ps, lr->gdev,
linereq_read_unlocked);
}
static void linereq_free(struct linereq *lr) static void linereq_free(struct linereq *lr)
{ {
struct line *line; struct line *line;
@ -1938,12 +1873,14 @@ struct lineevent_state {
(GPIOEVENT_REQUEST_RISING_EDGE | \ (GPIOEVENT_REQUEST_RISING_EDGE | \
GPIOEVENT_REQUEST_FALLING_EDGE) GPIOEVENT_REQUEST_FALLING_EDGE)
static __poll_t lineevent_poll_unlocked(struct file *file, static __poll_t lineevent_poll(struct file *file,
struct poll_table_struct *wait) struct poll_table_struct *wait)
{ {
struct lineevent_state *le = file->private_data; struct lineevent_state *le = file->private_data;
__poll_t events = 0; __poll_t events = 0;
guard(rwsem_read)(&le->gdev->sem);
if (!le->gdev->chip) if (!le->gdev->chip)
return EPOLLHUP | EPOLLERR; return EPOLLHUP | EPOLLERR;
@ -1955,14 +1892,6 @@ static __poll_t lineevent_poll_unlocked(struct file *file,
return events; return events;
} }
static __poll_t lineevent_poll(struct file *file,
struct poll_table_struct *wait)
{
struct lineevent_state *le = file->private_data;
return call_poll_locked(file, wait, le->gdev, lineevent_poll_unlocked);
}
static int lineevent_unregistered_notify(struct notifier_block *nb, static int lineevent_unregistered_notify(struct notifier_block *nb,
unsigned long action, void *data) unsigned long action, void *data)
{ {
@ -1979,8 +1908,8 @@ struct compat_gpioeevent_data {
u32 id; u32 id;
}; };
static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf, static ssize_t lineevent_read(struct file *file, char __user *buf,
size_t count, loff_t *f_ps) size_t count, loff_t *f_ps)
{ {
struct lineevent_state *le = file->private_data; struct lineevent_state *le = file->private_data;
struct gpioevent_data ge; struct gpioevent_data ge;
@ -1988,6 +1917,8 @@ static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
ssize_t ge_size; ssize_t ge_size;
int ret; int ret;
guard(rwsem_read)(&le->gdev->sem);
if (!le->gdev->chip) if (!le->gdev->chip)
return -ENODEV; return -ENODEV;
@ -2042,15 +1973,6 @@ static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
return bytes_read; return bytes_read;
} }
static ssize_t lineevent_read(struct file *file, char __user *buf,
size_t count, loff_t *f_ps)
{
struct lineevent_state *le = file->private_data;
return call_read_locked(file, buf, count, f_ps, le->gdev,
lineevent_read_unlocked);
}
static void lineevent_free(struct lineevent_state *le) static void lineevent_free(struct lineevent_state *le)
{ {
if (le->device_unregistered_nb.notifier_call) if (le->device_unregistered_nb.notifier_call)
@ -2071,13 +1993,15 @@ static int lineevent_release(struct inode *inode, struct file *file)
return 0; return 0;
} }
static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd, static long lineevent_ioctl(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
{ {
struct lineevent_state *le = file->private_data; struct lineevent_state *le = file->private_data;
void __user *ip = (void __user *)arg; void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd; struct gpiohandle_data ghd;
guard(rwsem_read)(&le->gdev->sem);
if (!le->gdev->chip) if (!le->gdev->chip)
return -ENODEV; return -ENODEV;
@ -2103,15 +2027,6 @@ static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd,
return -EINVAL; return -EINVAL;
} }
static long lineevent_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct lineevent_state *le = file->private_data;
return call_ioctl_locked(file, cmd, arg, le->gdev,
lineevent_ioctl_unlocked);
}
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT
static long lineevent_ioctl_compat(struct file *file, unsigned int cmd, static long lineevent_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
@ -2584,12 +2499,17 @@ static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip)
return 0; return 0;
} }
static long gpio_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned long arg) /*
* gpio_ioctl() - ioctl handler for the GPIO chardev
*/
static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{ {
struct gpio_chardev_data *cdev = file->private_data; struct gpio_chardev_data *cdev = file->private_data;
struct gpio_device *gdev = cdev->gdev; struct gpio_device *gdev = cdev->gdev;
void __user *ip = (void __user *)arg; void __user *ip = (void __user *)arg;
guard(rwsem_read)(&gdev->sem);
/* We fail any subsequent ioctl():s when the chip is gone */ /* We fail any subsequent ioctl():s when the chip is gone */
if (!gdev->chip) if (!gdev->chip)
return -ENODEV; return -ENODEV;
@ -2621,17 +2541,6 @@ static long gpio_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned lo
} }
} }
/*
* gpio_ioctl() - ioctl handler for the GPIO chardev
*/
static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct gpio_chardev_data *cdev = file->private_data;
return call_ioctl_locked(file, cmd, arg, cdev->gdev,
gpio_ioctl_unlocked);
}
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT
static long gpio_ioctl_compat(struct file *file, unsigned int cmd, static long gpio_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
@ -2679,12 +2588,14 @@ static int gpio_device_unregistered_notify(struct notifier_block *nb,
return NOTIFY_OK; return NOTIFY_OK;
} }
static __poll_t lineinfo_watch_poll_unlocked(struct file *file, static __poll_t lineinfo_watch_poll(struct file *file,
struct poll_table_struct *pollt) struct poll_table_struct *pollt)
{ {
struct gpio_chardev_data *cdev = file->private_data; struct gpio_chardev_data *cdev = file->private_data;
__poll_t events = 0; __poll_t events = 0;
guard(rwsem_read)(&cdev->gdev->sem);
if (!cdev->gdev->chip) if (!cdev->gdev->chip)
return EPOLLHUP | EPOLLERR; return EPOLLHUP | EPOLLERR;
@ -2697,17 +2608,8 @@ static __poll_t lineinfo_watch_poll_unlocked(struct file *file,
return events; return events;
} }
static __poll_t lineinfo_watch_poll(struct file *file, static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
struct poll_table_struct *pollt) size_t count, loff_t *off)
{
struct gpio_chardev_data *cdev = file->private_data;
return call_poll_locked(file, pollt, cdev->gdev,
lineinfo_watch_poll_unlocked);
}
static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
size_t count, loff_t *off)
{ {
struct gpio_chardev_data *cdev = file->private_data; struct gpio_chardev_data *cdev = file->private_data;
struct gpio_v2_line_info_changed event; struct gpio_v2_line_info_changed event;
@ -2715,6 +2617,8 @@ static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
int ret; int ret;
size_t event_size; size_t event_size;
guard(rwsem_read)(&cdev->gdev->sem);
if (!cdev->gdev->chip) if (!cdev->gdev->chip)
return -ENODEV; return -ENODEV;
@ -2777,15 +2681,6 @@ static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
return bytes_read; return bytes_read;
} }
static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
size_t count, loff_t *off)
{
struct gpio_chardev_data *cdev = file->private_data;
return call_read_locked(file, buf, count, off, cdev->gdev,
lineinfo_watch_read_unlocked);
}
/** /**
* gpio_chrdev_open() - open the chardev for ioctl operations * gpio_chrdev_open() - open the chardev for ioctl operations
* @inode: inode for this chardev * @inode: inode for this chardev
@ -2799,17 +2694,15 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
struct gpio_chardev_data *cdev; struct gpio_chardev_data *cdev;
int ret = -ENOMEM; int ret = -ENOMEM;
down_read(&gdev->sem); guard(rwsem_read)(&gdev->sem);
/* Fail on open if the backing gpiochip is gone */ /* Fail on open if the backing gpiochip is gone */
if (!gdev->chip) { if (!gdev->chip)
ret = -ENODEV; return -ENODEV;
goto out_unlock;
}
cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
if (!cdev) if (!cdev)
goto out_unlock; return -ENODEV;
cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
if (!cdev->watched_lines) if (!cdev->watched_lines)
@ -2838,8 +2731,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
if (ret) if (ret)
goto out_unregister_device_notifier; goto out_unregister_device_notifier;
up_read(&gdev->sem);
return ret; return ret;
out_unregister_device_notifier: out_unregister_device_notifier:
@ -2853,8 +2744,6 @@ out_free_bitmap:
bitmap_free(cdev->watched_lines); bitmap_free(cdev->watched_lines);
out_free_cdev: out_free_cdev:
kfree(cdev); kfree(cdev);
out_unlock:
up_read(&gdev->sem);
return ret; return ret;
} }