Feb. 24, 2012
7:07 a.m.
Imagine a driver which only one app can use at a time (perhaps a serial port). The kernel will take a lock when the user space app open()s the device node and release it when it close()s. If the app segfaults in between the open() and close() the lock will still get released. The kernel always cleans up open files for stopped processes, regardless of how they stop. During this cleanup the kernel will close() the device node, and as a result the driver will release the lock.
Can you please point to some code in Linux Kernel that does the job? Thanks, --- KostaZ