tools/testing/selftests/media_tests/regression_test.txt

Source file repositories/reference/linux-study-clean/tools/testing/selftests/media_tests/regression_test.txt

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/media_tests/regression_test.txt
Extension
.txt
Size
1624 bytes
Lines
44
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

Testing for regressions in Media Controller API register, ioctl, syscall,
and unregister paths. There have a few problems that result in use-after
free on media_device, media_devnode, and cdev pointers when the driver is
unbound while ioctl is in progress.

Test Procedure:

Run bin/unbind loop while ioctls are in progress.
Run rmmod and modprobe.
Disconnect the device.

Setup:

Build media_device_test
cd tools/testing/selftests/media_tests
make

Regressions test for cdev use-after-free error on /dev/mediaX when driver
is unbound:

Start media_device_test to regression test media devnode dynamic alloc
and cdev use-after-free fixes. This opens media dev files and sits in
a loop running media ioctl MEDIA_IOC_DEVICE_INFO command once every 10
seconds. The idea is when device file goes away, media devnode and cdev
should stick around until this test exits.

The test for a random number of iterations or until user kills it with a
sleep 10 in between the ioctl calls.

sudo ./media_device_test -d /dev/mediaX

Regression test for media_devnode unregister race with ioctl_syscall:

Start 6 open_loop_test.sh tests with different /dev/mediaX files. When
device file goes away after unbind, device file name changes. Start the
test with possible device names. If we start with /dev/media0 for example,
after unbind, /dev/media1 or /dev/media2 could get created. The idea is
keep ioctls going while bind/unbind runs.

Copy bind_unbind_sample.txt and make changes to specify the driver name
and number to run bind and unbind. Start the bind_unbind.sh

Run dmesg looking for any use-after-free errors or mutex lock errors.

Annotation

Implementation Notes