[PATCH 5.19 053/207] gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully

Greg Kroah-Hartman
2022-09-26T11:38:02Z

From: Meng Li <Meng.Li@windriver.com>

commit 69bef19d6b9700e96285f4b4e28691cda3dcd0d1 upstream.

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: 468242724143 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpio/gpiolib-cdev.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -1975,7 +1975,6 @@ static int lineevent_create(struct gpio_
ret = -ENODEV;
goto out_free_le;
}
- le->irq = irq;

if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
@@ -1989,7 +1988,7 @@ static int lineevent_create(struct gpio_
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,
@@ -1998,6 +1997,8 @@ static int lineevent_create(struct gpio_
if (ret)
goto out_free_le;

+ le->irq = irq;
+
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;