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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Meng Li <Meng.Li@windriver.com>,
        Kent Gibson <warthog618@gmail.com>,
        Bartosz Golaszewski <brgl@bgdev.pl>
Subject: [PATCH 5.19 053/207] gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully
Date:   Mon, 26 Sep 2022 12:10:42 +0200
Message-Id: <20220926100808.996403154@linuxfoundation.org>
In-Reply-To: <20220926100806.522017616@linuxfoundation.org>
References: <20220926100806.522017616@linuxfoundation.org>
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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;