kernel/system/do_getksig.c

   1 /* The kernel call that is implemented in this file:
   2  *   m_type:    SYS_GETKSIG
   3  *
   4  * The parameters for this kernel call are:
   5  *     m2_i1:   SIG_ENDPT       # process with pending signals
   6  *     m2_l1:   SIG_MAP         # bit map with pending signals
   7  */
   8
   9 #include "../system.h"
  10 #include <signal.h>
  11 #include <sys/sigcontext.h>
  12 #include <minix/endpoint.h>
  13
  14 #if USE_GETKSIG
  15
  16 /*===========================================================================*
  17  *                            do_getksig                                     *
  18  *===========================================================================*/
  19 PUBLIC int do_getksig(m_ptr)
  20 message *m_ptr;                 /* pointer to request message */
  21 {
  22 /* PM is ready to accept signals and repeatedly does a kernel call to get
  23  * one. Find a process with pending signals. If no signals are available,
  24  * return NONE in the process number field.
  25  * It is not sufficient to ready the process when PM is informed, because
  26  * PM can block waiting for FS to do a core dump.
  27  */
  28   register struct proc *rp;
  29
  30   /* Find the next process with pending signals. */
  31   for (rp = BEG_USER_ADDR; rp < END_PROC_ADDR; rp++) {
  32       if (RTS_ISSET(rp, SIGNALED)) {
  33           /* store signaled process' endpoint */
  34           m_ptr->SIG_ENDPT = rp->p_endpoint;
  35           m_ptr->SIG_MAP = rp->p_pending;       /* pending signals map */
  36           sigemptyset(&rp->p_pending);          /* ball is in PM's court */
  37           RTS_LOCK_UNSET(rp, SIGNALED);         /* blocked by SIG_PENDING */
  38           return(OK);
  39       }
  40   }
  41
  42   /* No process with pending signals was found. */
  43   m_ptr->SIG_ENDPT = NONE;
  44   return(OK);
  45 }
  46 #endif /* USE_GETKSIG */
  47