On Thu, Oct 03, 2002 at 03:21:51PM -0700, Seth Arnold wrote: > On Thu, Oct 03, 2002 at 12:30:46PM +0530, Anjaneyulu wrote: > [anj, your emails would be easier to read if you wrapped your line at 72 > characters] > > > I would like to know how to pass some information to the user process > > when I am raising a signal from kernel space. > > Have your signal handler in your user process set a flag, informing your > user process's main loop to read a /proc/ file, sysctl, ioctl, character > device, etc, when it next has a chance. > > Traditional unix signals cannot send more than just their number to a > process. POSIX Realtime signals can send more data, but I am not clear > the level of POSIX realtime signal support in the linux kernel. > (O'Reilly has a very nice book on realtime programming, released perhaps > 1994..) Well, many signals send additional info. Actually all signals have some. It's however limited to what can be included in the siginfo structure (see sigaction(2)). In kernel, you use send_sig_info function, to set this structure. Note, that from userland, it's not possible (when using kill). Kernel sets it up using pid and uid of the sending process. ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
