Implement sigtimedwait for use by suckless init

Makefile

@@ -3,7 +3,7 @@
 TOPDIR = $(CURDIR)
 
 # Directories which require calling make recursively
-SUBDIR = sys lib bin usr.bin etc include contrib
+SUBDIR = sys lib bin usr.bin sbin etc include contrib
 
 all: install
 

bin/utest/main.c

@@ -48,6 +48,8 @@ int main(int argc, char **argv) {
   CHECKRUN_TEST(signal_cont_masked);
   CHECKRUN_TEST(signal_mask);
   CHECKRUN_TEST(signal_mask_nonmaskable);
+  CHECKRUN_TEST(signal_sigtimedwait);
+  CHECKRUN_TEST(signal_sigtimedwait_timeout);
   CHECKRUN_TEST(signal_sigsuspend);
   CHECKRUN_TEST(signal_sigsuspend_stop);
   CHECKRUN_TEST(signal_handler_mask);

bin/utest/signal.c

@@ -1,10 +1,13 @@
 #include <assert.h>
 #include <signal.h>
 #include <stdio.h>
+#include <errno.h>
 #include <unistd.h>
 #include <sched.h>
 #include <sys/wait.h>
 
+#include "sys/errno.h"
+#include "sys/signal.h"
 #include "utest.h"
 #include "util.h"
 
@@ -287,6 +290,88 @@ int test_signal_sigsuspend(void) {
   return 0;
 }
 
+/* ======= signal_sigtimedwait ======= */
+int test_signal_sigtimedwait(void) {
+  pid_t ppid = getpid();
+  signal(SIGCONT, sigcont_handler);
+  sigset_t set, current, waitset;
+  __sigemptyset(&set);
+  __sigaddset(&set, SIGUSR1);
+  __sigaddset(&set, SIGCONT);
+  assert(sigprocmask(SIG_SETMASK, &set, NULL) == 0);
+  pid_t cpid = fork();
+  if (cpid == 0) {
+    // for (int i = 0; i < 10; i++) {
+    //   kill(ppid, SIGCONT);
+    // }
+    // sched_yield();
+    kill(ppid, SIGUSR1);
+    return 0;
+  }
+
+  printf("Calling sigtimedwait()...\n");
+  siginfo_t info;
+  __sigemptyset(&waitset);
+  __sigaddset(&waitset, SIGUSR1);
+  assert(sigtimedwait(&waitset, &info, NULL) == SIGUSR1);
+  assert(info.si_signo == SIGUSR1);
+  sigprocmask(SIG_BLOCK, NULL, &current);
+  assert(__sigsetequal(&set, &current));
+
+  printf("Waiting for child...\n");
+  int status;
+  wait(&status);
+  assert(WIFEXITED(status));
+  assert(WEXITSTATUS(status) == 0);
+  return 0;
+}
+
+/* ======= signal_sigtimedwait_timeout ======= */
+static int sigusr2_handled = 0;
+
+void sigtimedwait_timeout_sigusr2_handler(int signo) {
+  sigusr2_handled = 1;
+}
+
+int test_signal_sigtimedwait_timeout(void) {
+  pid_t ppid = getpid();
+  signal(SIGCONT, sigcont_handler);
+  signal(SIGUSR2, sigtimedwait_timeout_sigusr2_handler);
+  sigset_t set, waitset;
+  __sigemptyset(&set);
+  __sigaddset(&set, SIGUSR1);
+  assert(sigprocmask(SIG_SETMASK, &set, NULL) == 0);
+  pid_t cpid = fork();
+  if (cpid == 0) {
+    while (!sigusr2_handled) {
+      kill(ppid, SIGCONT);
+    }
+    return 0;
+  }
+
+  printf("Calling sigtimedwait()...\n");
+  siginfo_t info;
+  __sigemptyset(&waitset);
+  __sigaddset(&waitset, SIGUSR1);
+  timespec_t timeout = {
+    .tv_nsec = 10000000,
+    .tv_sec = 0,
+  };
+  assert(sigtimedwait(&waitset, &info, &timeout) == -1);
+  assert(errno == EINTR);
+  kill(cpid, SIGUSR2);
+  nanosleep(&timeout, NULL);
+  assert(sigtimedwait(&waitset, &info, &timeout) == -1);
+  assert(errno == EAGAIN);
+
+  printf("Waiting for child...\n");
+  int status;
+  wait(&status);
+  assert(WIFEXITED(status));
+  assert(WEXITSTATUS(status) == 0);
+  return 0;
+}
+
 /* ======= signal_sigsuspend_stop ======= */
 int test_signal_sigsuspend_stop(void) {
   pid_t ppid = getpid();

bin/utest/utest.h

@@ -41,6 +41,8 @@ int test_signal_stop(void);
 int test_signal_cont_masked(void);
 int test_signal_mask(void);
 int test_signal_mask_nonmaskable(void);
+int test_signal_sigtimedwait(void);
+int test_signal_sigtimedwait_timeout(void);
 int test_signal_sigsuspend(void);
 int test_signal_sigsuspend_stop(void);
 int test_signal_handler_mask(void);

etc/Makefile

@@ -2,7 +2,7 @@
 
 TOPDIR = $(realpath ..)
 
-FILES = group master.passwd .kshrc shells
+FILES = group master.passwd rc.init rc.shutdown .kshrc shells
 INSTALL-FILES = $(addprefix $(SYSROOT)/etc/, $(FILES))
 
 all: build
@@ -12,3 +12,6 @@ include $(TOPDIR)/build/common.mk
 $(SYSROOT)/etc/%: %
 	echo "[INSTALL] $(DIR)$* -> /etc/$*"
 	$(INSTALL) -m 644 -D $< $@
+
+install-here:
+	chmod 755 $(SYSROOT)/etc/rc.*

etc/rc.init

@@ -0,0 +1,13 @@
+#!/bin/ksh
+
+umask 022
+
+echo "  __  __ _           _ _              ____   _____  "
+echo " |  \/  (_)         (_) |            / __ \ / ____| "
+echo " | \  / |_ _ __ ___  _| | _____ _ __| |  | | (___   "
+echo " | |\/| | | '_ \` _ \| | |/ / _ \ '__| |  | |\___ \  "
+echo " | |  | | | | | | | | |   <  __/ |  | |__| |____) | "
+echo " |_|  |_|_|_| |_| |_|_|_|\_\___|_|   \____/|_____/  "
+echo
+
+exec /bin/ksh

etc/rc.shutdown

@@ -0,0 +1,3 @@
+#!/bin/ksh
+
+echo "Shutdown not supported yet!"

include/signal.h

@@ -35,6 +35,7 @@
 #define _SIGNAL_H_
 
 #include <sys/cdefs.h>
+#include <sys/time.h>
 #include <sys/signal.h>
 
 __BEGIN_DECLS
@@ -68,6 +69,13 @@ int sigsuspend(const sigset_t *);
 int killpg(int pgrp, int sig);
 int siginterrupt(int sig, int flag);
 
+/*
+ * X/Open CAE Specification Issue 5; IEEE Std 1003.1b-1993 (POSIX)
+ */
+int sigwait(const sigset_t *__restrict, int *__restrict);
+int sigtimedwait(const sigset_t *__restrict set, siginfo_t *__restrict info,
+                 const struct timespec *__restrict timeout);
+
 /*
  * Mimiker specific stuff.
  */

include/sys/signal.h

@@ -3,6 +3,7 @@
 
 #include <sys/sigtypes.h>
 #include <sys/siginfo.h>
+#include <sys/time.h>
 
 #define SIGHUP 1    /* hangup */
 #define SIGINT 2    /* interrupt */
@@ -201,6 +202,8 @@ void sig_onexec(proc_t *p);
 int do_sigaction(signo_t sig, const sigaction_t *act, sigaction_t *oldact);
 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oset);
 int do_sigsuspend(proc_t *p, const sigset_t *mask);
+int do_sigtimedwait(proc_t *p, sigset_t waitset, ksiginfo_t *kinfo,
+                    struct timespec *timeout);
 int do_sigpending(proc_t *p, sigset_t *set);
 
 #endif /* !_KERNEL */

include/sys/syscall.h

@@ -91,6 +91,7 @@
 #define SYS_fsync 83
 #define SYS_kqueue1 84
 #define SYS_kevent 85
-#define SYS_MAXSYSCALL 86
+#define SYS_sigtimedwait 86
+#define SYS_MAXSYSCALL 87
 
 #define SYS_MAXSYSARGS 6

include/sys/syscallargs.h

@@ -8,6 +8,7 @@
 #include <sys/time.h>
 #include <sys/ucontext.h>
 #include <sys/sigtypes.h>
+#include <sys/siginfo.h>
 #define SCARG(p, x) ((p)->x.arg)
 #define SYSCALLARG(x) union { register_t _pad; x arg; }
 
@@ -435,3 +436,9 @@ typedef struct {
   SYSCALLARG(size_t) nevents;
   SYSCALLARG(const struct timespec *) timeout;
 } kevent_args_t;
+
+typedef struct {
+  SYSCALLARG(const sigset_t *) set;
+  SYSCALLARG(siginfo_t *) info;
+  SYSCALLARG(struct timespec *) timeout;
+} sigtimedwait_args_t;

lib/libc/sys/sigwait.c

@@ -0,0 +1,56 @@
+/* $NetBSD: sigwait.c,v 1.5 2012/03/20 16:26:12 matt Exp $ */
+
+/*-
+ * Copyright (c) 2003 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jaromir Dolecek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+
+/*
+ * This is wrapper around sigtimedwait(2), providing sigwait()
+ * implementation for userland.
+ */
+int
+sigwait(const sigset_t * __restrict set, int * __restrict signum)
+{
+	int saved_errno, new_errno, sig;
+
+	saved_errno = errno;
+	sig = sigtimedwait(set, NULL, NULL);
+	new_errno = errno;
+	errno = saved_errno;
+	if (sig < 0)
+		return (new_errno);
+	*signum = sig;
+	return (0);
+}

lib/libc/sys/syscalls.S

@@ -84,3 +84,4 @@ SYSCALL(sync, SYS_sync)
 SYSCALL(fsync, SYS_fsync)
 SYSCALL(kqueue1, SYS_kqueue1)
 SYSCALL(kevent, SYS_kevent)
+SYSCALL(sigtimedwait, SYS_sigtimedwait)

sbin/Makefile

@@ -0,0 +1,9 @@
+# vim: tabstop=8 shiftwidth=8 noexpandtab:
+
+TOPDIR = $(realpath ..)
+
+SUBDIR = init
+
+all: build
+
+include $(TOPDIR)/build/common.mk

sbin/init/LICENSE

@@ -0,0 +1,21 @@
+MIT/X Consortium License
+
+© 2014-2015 Dimitris Papastamos <[email protected]>
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

sbin/init/Makefile

@@ -0,0 +1,6 @@
+TOPDIR = $(realpath ../..)
+
+PROGRAM = init
+FORMAT-EXCLUDE = $(SOURCES)
+
+include $(TOPDIR)/build/build.prog.mk

sbin/init/README

@@ -0,0 +1,26 @@
+sinit - suckless init
+=====================
+
+sinit is a simple init.  It was initially based on
+Rich Felker's minimal init[1].
+
+Why?
+----
+
+I wanted to get rid of Busybox init on my toy distro[2].
+
+How?
+----
+
+There are 3 signals that sinit will act on.
+
+      SIGUSR1: powers off the machine.
+      SIGINT:  reboots the machine (or alternatively via ctrl-alt-del).
+      SIGCHLD: reap children
+
+To see how sinit integrates with the init scripts, then have
+a look at [3].
+
+[1] https://gist.github.com/rofl0r/6168719
+[2] http://git.2f30.org/morpheus/
+[3] http://git.2f30.org/ports/tree/fs/

sbin/init/config.h

@@ -0,0 +1,5 @@
+/* See LICENSE file for copyright and license details. */
+
+static char *const rcinitcmd[]     = { "/etc/rc.init", NULL };
+static char *const rcrebootcmd[]   = { "/etc/rc.shutdown", "reboot", NULL };
+static char *const rcpoweroffcmd[] = { "/etc/rc.shutdown", "poweroff", NULL };