diff options
| author | Grant Likely <grant.likely@secretlab.ca> | 2013-02-09 13:41:49 +0400 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2013-02-12 02:21:28 +0400 |
| commit | 362432aed5e5b497a8cf7b20c268ba71df93c045 (patch) | |
| tree | 4a87f9533b3310c0bbd2a87477bf52bb0286cf41 /drivers/gpio | |
| parent | 6c0b4e6c85d085bd92966bc2b8da73e2d7f35929 (diff) | |
| download | linux-362432aed5e5b497a8cf7b20c268ba71df93c045.tar.xz | |
gpiolib: Fix locking on gpio debugfs files
The debugfs files really need to hold the gpiolib spinlock before
accessing the list. Otherwise chip addition/removal will cause an oops.
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5050693dcc35..4b3f388bcc6d 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2053,29 +2053,35 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { + unsigned long flags; struct gpio_chip *chip = NULL; loff_t index = *pos; - /* REVISIT this isn't locked against gpio_chip removal ... */ - s->private = ""; + spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(chip, &gpio_chips, list) - if (index-- == 0) + if (index-- == 0) { + spin_unlock_irqrestore(&gpio_lock, flags); return chip; + } + spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { + unsigned long flags; struct gpio_chip *chip = v; void *ret = NULL; + spin_lock_irqsave(&gpio_lock, flags); if (list_is_last(&chip->list, &gpio_chips)) ret = NULL; else ret = list_entry(chip->list.next, struct gpio_chip, list); + spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; ++*pos; |