minix/kernel/system/do_kill.c

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/* The kernel call that is implemented in this file:
* m_type: SYS_KILL
*
* The parameters for this kernel call are:
* m2_i1: SIG_PROC # process to signal/ pending
* m2_i2: SIG_NUMBER # signal number to send to process
*/
#include "../system.h"
#include <signal.h>
#include <sys/sigcontext.h>
#if USE_KILL
/*===========================================================================*
* do_kill *
*===========================================================================*/
PUBLIC int do_kill(m_ptr)
message *m_ptr; /* pointer to request message */
{
/* Handle sys_kill(). Cause a signal to be sent to a process. The PM is the
* central server where all signals are processed and handler policies can
* be registered. Any request, except for PM requests, is added to the map
* of pending signals and the PM is informed about the new signal.
* Since system servers cannot use normal POSIX signal handlers (because they
* are usually blocked on a RECEIVE), they can request the PM to transform
* signals into messages. This is done by the PM with a call to sys_kill().
*/
proc_nr_t proc_nr = m_ptr->SIG_PROC;
int sig_nr = m_ptr->SIG_NUMBER;
if (! isokprocn(proc_nr) || sig_nr > _NSIG) return(EINVAL);
if (iskerneln(proc_nr)) return(EPERM);
if (m_ptr->m_source == PM_PROC_NR) {
/* Directly send signal notification to a system process. */
if (! (priv(proc_addr(proc_nr))->s_flags & SYS_PROC)) return(EPERM);
send_sig(proc_nr, sig_nr);
} else {
/* Set pending signal to be processed by the PM. */
cause_sig(proc_nr, sig_nr);
}
return(OK);
}
#endif /* USE_KILL */