* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
- *
- * Note that we go through the signals twice: once to check the signals
- * that the kernel can handle, and then we build all the user-level signal
- * handling stack-frames in one go after that.
*/
asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
{
+ struct k_sigaction ka;
siginfo_t info;
- struct k_sigaction *ka;
-
- current->thread.esp0 = (unsigned long) regs;
+ int signr;
+
+ /*
+ * We want the common case to go fast, which
+ * is why we may in certain cases get here from
+ * kernel mode. Just return without doing anything
+ * if so.
+ */
+ if (!user_mode(regs))
+ return 1;
if (!oldset)
oldset = ¤t->blocked;
- for (;;) {
- int signr;
-
- signr = get_signal_to_deliver(&info, regs, NULL);
-
- if (!signr)
- break;
-
- if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
- current->exit_code = signr;
- current->state = TASK_STOPPED;
- regs->sr &= ~PS_T;
-
- /* Did we come from a system call? */
- if (regs->orig_d0 >= 0) {
- /* Restart the system call the same way as
- if the process were not traced. */
- struct k_sigaction *ka =
- ¤t->sighand->action[signr-1];
- int has_handler =
- (ka->sa.sa_handler != SIG_IGN &&
- ka->sa.sa_handler != SIG_DFL);
- handle_restart(regs, ka, has_handler);
- }
- notify_parent(current, SIGCHLD);
- schedule();
-
- /* We're back. Did the debugger cancel the sig? */
- if (!(signr = current->exit_code)) {
- discard_frame:
- continue;
- }
- current->exit_code = 0;
-
- /* The debugger continued. Ignore SIGSTOP. */
- if (signr == SIGSTOP)
- goto discard_frame;
-
- /* Update the siginfo structure. Is this good? */
- if (signr != info.si_signo) {
- info.si_signo = signr;
- info.si_errno = 0;
- info.si_code = SI_USER;
- info.si_pid = current->parent->pid;
- info.si_uid = current->parent->uid;
- }
-
- /* If the (new) signal is now blocked, requeue it. */
- if (sigismember(¤t->blocked, signr)) {
- send_sig_info(signr, &info, current);
- continue;
- }
- }
-
- ka = ¤t->sighand->action[signr-1];
- if (ka->sa.sa_handler == SIG_IGN) {
- if (signr != SIGCHLD)
- continue;
- /* Check for SIGCHLD: it's special. */
- while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
- /* nothing */;
- continue;
- }
-
- if (ka->sa.sa_handler == SIG_DFL) {
- int exit_code = signr;
-
- if (current->pid == 1)
- continue;
-
- switch (signr) {
- case SIGCONT: case SIGCHLD:
- case SIGWINCH: case SIGURG:
- continue;
-
- case SIGTSTP: case SIGTTIN: case SIGTTOU:
- if (is_orphaned_pgrp(process_group(current)))
- continue;
- /* FALLTHRU */
-
- case SIGSTOP:
- current->state = TASK_STOPPED;
- current->exit_code = signr;
- if (!(current->parent->sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))
- notify_parent(current, SIGCHLD);
- schedule();
- continue;
-
- case SIGQUIT: case SIGILL: case SIGTRAP:
- case SIGIOT: case SIGFPE: case SIGSEGV:
- case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ:
- if (do_coredump(signr, exit_code, regs))
- exit_code |= 0x80;
- /* FALLTHRU */
-
- default:
- sigaddset(¤t->pending.signal, signr);
- recalc_sigpending();
- current->flags |= PF_SIGNALED;
- do_exit(exit_code);
- /* NOTREACHED */
- }
- }
-
+ signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+ if (signr > 0) {
/* Whee! Actually deliver the signal. */
- handle_signal(signr, ka, &info, oldset, regs);
+ handle_signal(signr, &ka, &info, oldset, regs);
return 1;
}
/* Did we come from a system call? */
- if (regs->orig_d0 >= 0)
+ if (regs->orig_d0 >= 0) {
/* Restart the system call - no handlers present */
- handle_restart(regs, NULL, 0);
-
- /* If we are about to discard some frame stuff we must copy
- over the remaining frame. */
- if (regs->stkadj) {
- struct pt_regs *tregs =
- (struct pt_regs *) ((ulong) regs + regs->stkadj);
-
- /* This must be copied with decreasing addresses to
- handle overlaps. */
- tregs->vector = 0;
- tregs->format = 0;
- tregs->pc = regs->pc;
- tregs->sr = regs->sr;
+ if (regs->d0 == -ERESTARTNOHAND
+ || regs->d0 == -ERESTARTSYS
+ || regs->d0 == -ERESTARTNOINTR) {
+ regs->d0 = regs->orig_d0;
+ regs->pc -= 2;
+ } else if (regs->d0 == -ERESTART_RESTARTBLOCK) {
+ regs->d0 = __NR_restart_syscall;
+ regs->pc -= 2;
+ }
}
return 0;
}