Commit 69bef19d authored Sep 21, 2022 by Meng Li Committed by Bartosz Golaszewski Sep 21, 2022

gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully



When running gpio test on nxp-ls1028 platform with below command
gpiomon --num-events=3 --rising-edge gpiochip1 25
There will be a warning trace as below:
Call trace:
free_irq+0x204/0x360
lineevent_free+0x64/0x70
gpio_ioctl+0x598/0x6a0
__arm64_sys_ioctl+0xb4/0x100
invoke_syscall+0x5c/0x130
......
el0t_64_sync+0x1a0/0x1a4
The reason of this issue is that calling request_threaded_irq()
function failed, and then lineevent_free() is invoked to release
the resource. Since the lineevent_state::irq was already set, so
the subsequent invocation of free_irq() would trigger the above
warning call trace. To fix this issue, set the lineevent_state::irq
after the IRQ register successfully.

Fixes: 46824272 ("gpiolib: cdev: refactor lineevent cleanup into lineevent_free")
Cc: stable@vger.kernel.org
Signed-off-by: Meng Li <Meng.Li@windriver.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

parent 21a9acc1

drivers/gpio/gpiolib-cdev.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1986,7 +1986,6 @@ static int lineevent_create(struct gpio_device gdev, void __user ip)
		ret = -ENODEV;
		goto out_free_le;
		}
		le->irq = irq;

		if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
		irqflags \|= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
		@@ -2000,7 +1999,7 @@ static int lineevent_create(struct gpio_device gdev, void __user ip)
		init_waitqueue_head(&le->wait);

		/* Request a thread to read the events */
		ret = request_threaded_irq(le->irq,
		ret = request_threaded_irq(irq,
		lineevent_irq_handler,
		lineevent_irq_thread,
		irqflags,
		@@ -2009,6 +2008,8 @@ static int lineevent_create(struct gpio_device gdev, void __user ip)
		if (ret)
		goto out_free_le;

		le->irq = irq;

		fd = get_unused_fd_flags(O_RDONLY \| O_CLOEXEC);
		if (fd < 0) {
		ret = fd;