Mastering Linux Kernel Development

Signal data structures

The kernel maintains per-process signal data structures to keep track of, signal disposition, blocked signals, and pending signal queues. The process task structure contains appropriate references to these data structures:

struct task_struct {............/* signal handlers */ struct signal_struct *signal; struct sighand_struct *sighand; sigset_t blocked, real_blocked; sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */ struct sigpending pending; unsigned long sas_ss_sp; size_t sas_ss_size; unsigned sas_ss_flags;  ....  ....  ....  ....};