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_PROC        # 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
  13 #if USE_GETKSIG
  14
  15 /*===========================================================================*
  16  *                            do_getksig                                     *
  17  *===========================================================================*/
  18 PUBLIC int do_getksig(m_ptr)
  19 message *m_ptr;                 /* pointer to request message */
  20 {
  21 /* PM is ready to accept signals and repeatedly does a kernel call to get
  22  * one. Find a process with pending signals. If no signals are available,
  23  * return NONE in the process number field.
  24  * It is not sufficient to ready the process when PM is informed, because
  25  * PM can block waiting for FS to do a core dump.
  26  */
  27   register struct proc *rp;
  28
  29   /* Find the next process with pending signals. */
  30   for (rp = BEG_USER_ADDR; rp < END_PROC_ADDR; rp++) {
  31       if (rp->p_rts_flags & SIGNALED) {
  32           m_ptr->SIG_PROC = rp->p_nr;           /* store signaled process */
  33           m_ptr->SIG_MAP = rp->p_pending;       /* pending signals map */
  34           sigemptyset(&rp->p_pending);          /* ball is in PM's court */
  35           rp->p_rts_flags &= ~SIGNALED;         /* blocked by SIG_PENDING */
  36           return(OK);
  37       }
  38   }
  39
  40   /* No process with pending signals was found. */
  41   m_ptr->SIG_PROC = NONE;
  42   return(OK);
  43 }
  44 #endif /* USE_GETKSIG */
  45