Thanks Dave for that reply. While i try out registering handlers for all possible signals, I forgot to mention this point in my previous email. The userspace is waiting on a select call. As per the system design, the kernel module interrupts when there is a data intended to the user (via poll in kernel). If this could be the cause for the userspace getting a signal, then typically what signal is generated to the process to invoke select to inform that the I/O is ready. Is it SIGIO? Regards, Vijay On Mon, Apr 4, 2011 at 9:18 PM, Dave Hylands <dhylands@xxxxxxxxx> wrote: > Hi Vijay, > > On Sun, Apr 3, 2011 at 9:27 PM, Vijay Ram Chitrapu > <chitrapu.vijayram@xxxxxxxxx> wrote: >> Hi Experts, >> >> I have a system in which there is a only 1 user process and a >> corresponding kernel module (driver) associated with it to send and >> receive data to the user process. In the kernel module, i have a >> semaphore to protect a critical section of code during the rx and tx >> paths. However, at some instance of code execution, the >> down_interruptible returns EINTR, which means that the user process >> has received some interrupt due to which the process has come out of >> sleep due to the signal it received, due to which the kernel module >> has not got the semaphore. At this point of time, i have no idea as to >> which signal has triggered the user process to come out of the sleep. >> Is there a way in which we can know which signal has a process >> received, without registering any user defined handler to it? >> >> Any thoughts/ideas on debugging this problem can be of great help. >> Also please correct me if i am wrong in any of my understanding >> regarding down_interruptible. > > The simplest way is to just register a signal handler for all possible > signals (in the user program) and print out which one actually > happened. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.davehylands.com > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
