I am sending a signal from kernel space to user space with Linux 2.4.20-8.
In user space, I have installed a signal handler:
saio.sa_handler = signal_handler_IO;
sigemptyset(&saio.sa_mask);
saio.sa_flags = SA_SIGINFO;
saio.sa_restorer = NULL;
sigaction(SA_SIGINFO, &saio, NULL);
In kernel space:
info.si_errno = 1212;
info.si_code = SI_KERNEL;
send_sig_info(SA_SIGINFO, &info, find_task_by_pid(pid));
This results in the signal handler,
void signal_handler_IO (int status, struct siginfo *info, void *p)
being called in user space, which gives the following values in info:
info->si_signo = 4 /* corresponds to SA_SIGINFO */
info->si_errno = 0 /* expect 1212 */
info->si_code = 0 /* expect SI_KERNEL (128) */
Note that the values I put in si_errno and si_code do not get passed to the
user. si_signo has the correct value, but the user can know this from the
original sigaction call.
If instead, I call send_sig_info(SA_SIGINFO, (struct siginfo*)0,
find_task_by_pid(pid)), as expected I get:
info->si_signo = 4
info->si_errno = 0
info->si_code = 0 /* corresponds to SI_USER, as expected */
If I call send_sig_info(SA_SIGINFO, (struct siginfo*)1,
find_task_by_pid(pid)), as expected I get:
info->si_signo = 4
info->si_errno = 0
info->si_code = 128 /* corresponds to SI_KERNEL, as expected */
Apparently, there is a problem copying the info structure. I need to pass
info to the kernel. Any ideas?
Thank you.
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