[PATCH] drm/tests: Alloc drm_device on drm_exec tests

[Arthur Grillo Queiroz Cabral]

On 28/07/23 11:33, Maxime Ripard wrote:
> Hi,
> 
> On Thu, Jul 27, 2023 at 04:22:59PM -0300, Arthur Grillo wrote:
>> The drm_exec tests where crashing[0] because of a null dereference. This
>> is caused by a new access of the `driver` attribute of `struct
>> drm_driver` on drm_gem_private_object_init(). Alloc the drm_device to
>> fix that.
>>
>> [0]
>> [15:05:24] ================== drm_exec (6 subtests) ===================
>> [15:05:24] [PASSED] sanitycheck
>> ^CERROR:root:Build interruption occurred. Cleaning console.
>> [15:05:50] [ERROR] Test: drm_exec: missing expected subtest!
>> [15:05:50] BUG: kernel NULL pointer dereference, address: 00000000000000b0
>> [15:05:50] #PF: supervisor read access in kernel mode
>> [15:05:50] #PF: error_code(0x0000) - not-present page
>> [15:05:50] PGD 0 P4D 0
>> [15:05:50] Oops: 0000 [#1] PREEMPT NOPTI
>> [15:05:50] CPU: 0 PID: 23 Comm: kunit_try_catch Tainted: G                 N 6.4.0-rc7-02032-ge6303f323b1a #69
>> [15:05:50] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014
>> [15:05:50] RIP: 0010:drm_gem_private_object_init+0x60/0xc0
>>
>> Fixes: e6303f323b1a ("drm: manager to keep track of GPUs VA mappings")
>> Signed-off-by: Arthur Grillo <arthurgrillo at riseup.net>
> 
> You should Cc the list of people returned by scripts/get_maintainers.pl
> for all your patches.
> 

The email of my patch that arrived in my inbox has all the people
returned by scripts/get_maintainers.pl on Cc, but the email on the list
has some people left out. Maybe is something wrong with my git
send-email configuration. I will have a look on that.

Best Regards,
~Arthur Grillo

>> ---
>>  drivers/gpu/drm/tests/drm_exec_test.c | 36 +++++++++++++++++++++------
>>  1 file changed, 29 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tests/drm_exec_test.c b/drivers/gpu/drm/tests/drm_exec_test.c
>> index 727ac267682e..df31f89a7945 100644
>> --- a/drivers/gpu/drm/tests/drm_exec_test.c
>> +++ b/drivers/gpu/drm/tests/drm_exec_test.c
>> @@ -12,11 +12,31 @@
>>  
>>  #include <drm/drm_exec.h>
>>  #include <drm/drm_device.h>
>> +#include <drm/drm_drv.h>
>>  #include <drm/drm_gem.h>
>> +#include <drm/drm_kunit_helpers.h>
>>  
>>  #include "../lib/drm_random.h"
>>  
>> -static struct drm_device dev;
>> +static struct device *dev;
>> +static struct drm_device *drm;
>> +
>> +static int test_init(struct kunit *test)
>> +{
>> +	dev = drm_kunit_helper_alloc_device(test);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
>> +
>> +	drm = __drm_kunit_helper_alloc_drm_device(test, dev, sizeof(*drm), 0,
>> +						  DRIVER_MODESET);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, drm);
>> +
>> +	return 0;
>> +}
>> +
>> +static void test_exit(struct kunit *test)
>> +{
>> +	drm_kunit_helper_free_device(test, dev);
>> +}
> 
> You shouldn't be using a global variable here. test->priv is meant for
> those kind of things.
> 
> Maxime