gpio: mockup: fix debugfs read (2583303d) · Commits · 戴 / test

The debugfs read callback must advance ppos or users using read() on the file descriptor will never get the EOL. This wasn't spotted before as I was using busybox cat for testing which uses sendfile() internally and only noticed it now when switched to cat from coreutils. Fixes: ("gpio: mockup: rework debugfs interface") Signed-off-by:

Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-mockup.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -204,8 +204,9 @@ static ssize_t gpio_mockup_debugfs_read(struct file *file,
		struct gpio_mockup_chip *chip;
		struct seq_file *sfile;
		struct gpio_chip *gc;
		int val, rv, cnt;
		char buf[3];
		int val, rv;


		if (*ppos != 0)
		return 0;
		@@ -216,13 +217,14 @@ static ssize_t gpio_mockup_debugfs_read(struct file *file,
		gc = &chip->gc;

		val = gpio_mockup_get(gc, priv->offset);
		snprintf(buf, sizeof(buf), "%d\n", val);
		cnt = snprintf(buf, sizeof(buf), "%d\n", val);

		rv = copy_to_user(usr_buf, buf, sizeof(buf));
		rv = copy_to_user(usr_buf, buf, cnt);
		if (rv)
		return rv;

		return sizeof(buf) - 1;
		*ppos += cnt;
		return cnt;
		}

		static ssize_t gpio_mockup_debugfs_write(struct file *file,

Admin message