root/kernel/syscalls/signal.c

/* */

DEFINITIONS

1. sys_signal

   1 /*
   2  * fiwix/kernel/syscalls/signal.c
   3  *
   4  * Copyright 2018-2021, Jordi Sanfeliu. All rights reserved.
   5  * Distributed under the terms of the Fiwix License.
   6  */
   7 
   8 #include <fiwix/syscalls.h>
   9 #include <fiwix/signal.h>
  10 #include <fiwix/process.h>
  11 #include <fiwix/errno.h>
  12 #include <fiwix/string.h>
  13 
  14 #ifdef __DEBUG__
  15 #include <fiwix/stdio.h>
  16 #endif /*__DEBUG__ */
  17 
  18 unsigned int sys_signal(__sigset_t signum, void(* sighandler)(int))
  19 {
  20         struct sigaction s;
  21         int errno;
  22 
  23 #ifdef __DEBUG__
  24         printk("(pid %d) sys_signal()\n", current->pid);
  25 #endif /*__DEBUG__ */
  26 
  27         if(signum < 1 || signum > NSIG) {
  28                 return -EINVAL;
  29         }
  30         if(signum == SIGKILL || signum == SIGSTOP) {
  31                 return -EINVAL;
  32         }
  33         if(sighandler != SIG_DFL && sighandler != SIG_IGN) {
  34                 if((errno = check_user_area(VERIFY_READ, sighandler, sizeof(unsigned int)))) {
  35                         return errno;
  36                 }
  37         }
  38 
  39         memset_b(&s, 0, sizeof(struct sigaction));
  40         s.sa_handler = sighandler;
  41         s.sa_mask = 0;
  42         s.sa_flags = SA_RESETHAND;
  43         sighandler = current->sigaction[signum - 1].sa_handler;
  44         current->sigaction[signum - 1] = s;
  45         if(current->sigaction[signum - 1].sa_handler == SIG_IGN) {
  46                 if(signum != SIGCHLD) {
  47                         current->sigpending &= SIG_MASK(signum);
  48                 }
  49         }
  50         if(current->sigaction[signum - 1].sa_handler == SIG_DFL) {
  51                 if(signum != SIGCHLD) {
  52                         current->sigpending &= SIG_MASK(signum);
  53                 }
  54         }
  55         return (unsigned int)sighandler;
  56 }

/* */