Klocwork check null before dereference in acl_profiler.cpp

[haoxian2]

Fixed the following Klocwork issue:

1. Pointer 'accel_def' returned from call to function 'acl_find_accel_def' at line 605 may be NULL and may be dereferenced at line 620.

acl_find_accl_def bails out if the return value would be NULL, therefore ensuring that accel_def can never be NULL if status == CL_SUCCESS. So an assert statement is included instead after the status check, which would rule out NULL return values.

[pcolberg]

Thanks @haoxian2! This one needs a bit more investigation as detailed below.

[haoxian2]

accel_def receives the return value of acl_find_accl_def, but acl_find_accl_def also sets the status variable. There's a line in acl_find_accl_def that specifically says if the return value would be NULL, then status would be set to CL_INVALID_KERNEL_NAME and it would return 0. Therefore, the subsequent status check would not pass if acl_find_accl_def would return a NULL. The assert inserted would only be reached if status == CL_SUCCESS.

[pcolberg]

accel_def receives the return value of acl_find_accl_def, but acl_find_accl_def also sets the status variable. There's a line in acl_find_accl_def that specifically says if the return value would be NULL, then status would be set to CL_INVALID_KERNEL_NAME and it would return 0. Therefore, the subsequent status check would not pass if acl_find_accl_def would return a NULL. The assert inserted would only be reached if status == CL_SUCCESS.

Thanks @haoxian2 for the detailed explanation and my apologies for missing this the first time, which you had already confirmed in the commit message.

[pcolberg]

Thanks @haoxian2. I pushed a minor revision of the commit message, adding a tag in the subject and moving the reasoning to the body to keep the subject brief.

[haoxian2]

Thanks @pcolberg for the revision!