Mastering Linux Kernel Development

Debug checks and validations

Incorrect use of mutex operations can cause deadlocks, failure of exclusion, and so on. To detect and prevent such possible occurrences, the mutex subsystem is equipped with appropriate checks or validations instrumented into mutex operations. These checks are by default disabled, and can be enabled by choosing the configuration option CONFIG_DEBUG_MUTEXES=y during kernel build.

Following is a list of checks enforced by instrumented debug code:

• Mutex can be owned by one task at a given point in time
• Mutex can be released (unlocked) only by the valid owner, and an attempt to release mutex by a context that does not own the lock will fail
• Recursive locking or unlocking attempts will fail
• A mutex can only be initialized ...