add fork_for_safety option + beginning of kernel-based keyboard

Signed-off-by: Mattias Andrée <maandree@operamail.com>

12 files changed, 742 insertions, 15 deletions

diff --git a/src/libmdsserver/util.c b/src/libmdsserver/util.c
index 01f5cbe..83641f2 100644
--- a/src/libmdsserver/util.c
+++ b/src/libmdsserver/util.c
@@ -28,6 +28,8 @@
 #include <sys/socket.h>
 #include <errno.h>
 #include <ctype.h>
+#include <time.h>
+#include <sys/wait.h>
 
 
 
@@ -294,3 +296,40 @@ int startswith_n(const char* haystack, const char* needle, size_t haystack_n, si
   return 1;
 }
 
+
+/**
+ * Wrapper around `waitpid` that never returns on an interruption unless
+ * it is interrupted 100 times within the same second
+ * 
+ * @param   pid  See description of `pid` in the documentation for `waitpid`
+ * @param   pid  See description of `status` in the documentation for `waitpid`
+ * @param   pid  See description of `options` in the documentation for `waitpid`
+ * @return       See the documentation for `waitpid`
+ */
+pid_t uninterruptable_waitpid(pid_t pid, int* restrict status, int options)
+{
+  struct timespec time_start;
+  struct timespec time_intr;
+  int intr_count = 0, have_time;
+  pid_t rc;
+  
+  have_time = (monotone(&time_start) >= 0);
+  
+ rewait:
+  rc = waitpid(pid, status, options);
+  if (rc == (pid_t)-1)
+    {
+      if (errno != EINTR)
+	goto fail;
+      if (have_time && (monotone(&time_intr) >= 0))
+	if (time_start.tv_sec != time_intr.tv_sec)
+	  intr_count = 0;
+      if (intr_count++ < 100)
+	goto rewait;
+      /* Don't let the CPU catch fire! */
+      errno = EINTR;
+    }
+ fail:
+  return rc;
+}
+
diff --git a/src/libmdsserver/util.h b/src/libmdsserver/util.h
index 00dfb58..3220adb 100644
--- a/src/libmdsserver/util.h
+++ b/src/libmdsserver/util.h
@@ -21,6 +21,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <sys/types.h>
 
 
 /**
@@ -113,6 +114,17 @@ char* full_read(int fd);
  */
 int startswith_n(const char* haystack, const char* needle, size_t haystack_n, size_t needle_n) __attribute__((pure));
 
+/**
+ * Wrapper around `waitpid` that never returns on an interruption unless
+ * it is interrupted 100 times within the same second
+ * 
+ * @param   pid  See description of `pid` in the documentation for `waitpid`
+ * @param   pid  See description of `status` in the documentation for `waitpid`
+ * @param   pid  See description of `options` in the documentation for `waitpid`
+ * @return       See the documentation for `waitpid`
+ */
+pid_t uninterruptable_waitpid(pid_t pid, int* restrict status, int options);
+
 
 #endif
 
diff --git a/src/mds-base.c b/src/mds-base.c
index 77b8835..1bae36b 100644
--- a/src/mds-base.c
+++ b/src/mds-base.c
@@ -182,12 +182,54 @@ int __attribute__((weak)) connect_to_display(void)
   return 1;
 }
 
+
+/**
+ * Put the server into a fork of itself as
+ * described by the `fork_for_safety`
+ * server characteristics
+ * 
+ * @return  Zero on success, -1 on error
+ */
+static int server_initialised_fork_for_safety(void)
+{
+  unsigned pending_alarm = alarm(0);
+  pid_t pid = fork();
+  
+  if (pid == (pid_t)-1)
+    {
+      xperror(*argv);
+      eprint("while forking for safety.");
+      return -1;
+    }
+  else if (pid == 0)
+    alarm(pending_alarm);
+  else
+    {
+      int status;
+      if (uninterruptable_waitpid(pid, &status, 0) == (pid_t)-1)
+	{
+	  xperror(*argv);
+	  kill(pid, SIGABRT);
+	  sleep(5);
+	}
+      fork_cleanup(status);
+      if      (WIFEXITED(status))    exit(WEXITSTATUS(status));
+      else if (WIFSIGNALED(status))  raise(WTERMSIG(status));
+      exit(1);
+    }
+  
+  return 0;
+}
+
+
 /**
  * This function should be called when the server has
  * been properly initialised but before initialisation
  * of anything that is removed at forking is initialised
+ * 
+ * @return  Zero on success, -1 on error
  */
-void __attribute__((weak)) server_initialised(void)
+int __attribute__((weak)) server_initialised(void)
 {
   pid_t r;
   if (on_init_fork && (r = fork()))
@@ -196,7 +238,7 @@ void __attribute__((weak)) server_initialised(void)
 	{
 	  xperror(*argv);
 	  eprint("while forking at completed initialisation.");
-	  exit(1);
+	  return -1;
 	}
       else
 	exit(0);
@@ -204,6 +246,10 @@ void __attribute__((weak)) server_initialised(void)
   
   if (on_init_sh != NULL)
     system(on_init_sh);
+  
+  if (server_characteristics.fork_for_safety)
+    return server_initialised_fork_for_safety();
+  return 0;
 }
 
 
@@ -495,5 +541,23 @@ int trap_signals(void)
 }
 
 
+/**
+ * This function should be implemented by the actual server implementation
+ * if the server has set `server_characteristics.fork_for_safety` to be
+ * true
+ * 
+ * This function is called by the parent server process when the
+ * child server process exits, if the server has completed its
+ * initialisation
+ * 
+ * @param  status  The status the child died with
+ */
+void __attribute__((weak)) fork_cleanup(int status)
+{
+  (void) status;
+  fprintf(stderr, "Something is wrong, `fork_cleanup` has been called but not reimplemented.");
+}
+
+
 #undef try
 
diff --git a/src/mds-base.h b/src/mds-base.h
index edc42fa..68feb32 100644
--- a/src/mds-base.h
+++ b/src/mds-base.h
@@ -54,6 +54,16 @@ typedef struct server_characteristics
    */
   unsigned sanity_check_argc : 1;
   
+  /**
+   * Setting this to non-zero will cause the server to place
+   * itself in a fork of itself when initialised. This can be
+   * used to let the server clean up fatal stuff after itself
+   * if it crashes. When the child exits, no matter how it
+   * exits, the parent will call `fork_cleanup` and then
+   * die it the same manner as the child.
+   */
+  unsigned fork_for_safety : 1;
+  
 } __attribute__((packed)) server_characteristics_t;
 
 
@@ -154,8 +164,10 @@ int connect_to_display(void); /* __attribute__((weak)) */
  * This function should be called when the server has
  * been properly initialised but before initialisation
  * of anything that is removed at forking is initialised
+ * 
+ * @return  Zero on success, -1 on error
  */
-void server_initialised(void); /* __attribute__((weak)) */
+int server_initialised(void); /* __attribute__((weak)) */
 
 
 /**
@@ -277,6 +289,19 @@ extern int reexec_failure_recover(void);
  */
 extern int master_loop(void);
 
+/**
+ * This function should be implemented by the actual server implementation
+ * if the server has set `server_characteristics.fork_for_safety` to be
+ * true
+ * 
+ * This function is called by the parent server process when the
+ * child server process exits, if the server has completed its
+ * initialisation
+ * 
+ * @param  status  The status the child died with
+ */
+void fork_cleanup(int status); /* __attribute__((weak)) */
+
 
 #endif
 
diff --git a/src/mds-clipboard.c b/src/mds-clipboard.c
index b4e47ab..21a2671 100644
--- a/src/mds-clipboard.c
+++ b/src/mds-clipboard.c
@@ -45,7 +45,8 @@ server_characteristics_t server_characteristics =
     .require_privileges = 0,
     .require_display = 1,
     .require_respawn_info = 1,
-    .sanity_check_argc = 1
+    .sanity_check_argc = 1,
+    .fork_for_safety = 0
   };
 
 
@@ -128,7 +129,7 @@ int initialise_server(void)
       message_id++;
     }
   
-  server_initialised();
+  fail_if (server_initialised() < 0);
   fail_if (mds_message_initialise(&received));
   
   for (i = 0; i < CLIPBOARD_LEVELS; i++)
diff --git a/src/mds-echo.c b/src/mds-echo.c
index 309c28d..01f8e97 100644
--- a/src/mds-echo.c
+++ b/src/mds-echo.c
@@ -45,7 +45,8 @@ server_characteristics_t server_characteristics =
     .require_privileges = 0,
     .require_display = 1,
     .require_respawn_info = 0,
-    .sanity_check_argc = 1
+    .sanity_check_argc = 1,
+    .fork_for_safety = 0
   };
 
 
@@ -106,7 +107,7 @@ int initialise_server(void)
   
   if (full_send(message, strlen(message)))
     return 1;
-  server_initialised();
+  fail_if (server_initialised() < 0);
   fail_if (mds_message_initialise(&received));
   
   return 0;
diff --git a/src/mds-kkbd.c b/src/mds-kkbd.c
new file mode 100644
index 0000000..51a8953
--- /dev/null
+++ b/src/mds-kkbd.c
@@ -0,0 +1,509 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "mds-kkbd.h"
+
+#include <libmdsserver/macros.h>
+#include <libmdsserver/util.h>
+#include <libmdsserver/mds-message.h>
+
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <linux/kd.h>
+#define reconnect_to_display() -1 /* TODO */
+
+
+
+#ifdef __sparc__
+# define GET_LED  KIOCGLED
+# define SET_LED  KIOCSLED
+#else
+# define GET_LED  KDGETLED
+# define SET_LED  KDSETLED
+#endif
+
+
+#ifdef __sparc__
+# define LED_NUM_LOCK   1
+# define LED_CAPS_LOCK  8
+# define LED_SCRL_LOCK  4
+# define LED_COMPOSE    2
+#else
+# define LED_NUM_LOCK   LED_NUM
+# define LED_CAPS_LOCK  LED_CAP
+# define LED_SCRL_LOCK  LED_SCR
+#endif
+
+
+
+#define MDS_KKBD_VARS_VERSION  0
+
+
+
+/**
+ * This variable should declared by the actual server implementation.
+ * It must be configured before `main` is invoked.
+ * 
+ * This tells the server-base how to behave
+ */
+server_characteristics_t server_characteristics =
+  {
+    .require_privileges = 0,
+    .require_display = 1,
+    .require_respawn_info = 0,
+    .sanity_check_argc = 1,
+    .fork_for_safety = 1
+  };
+
+
+
+/**
+ * Value of the ‘Message ID’ header for the next message
+ */
+static int32_t message_id = 1;
+
+/**
+ * Buffer for received messages
+ */
+static mds_message_t received;
+
+/**
+ * Whether the server is connected to the display
+ */
+static int connected = 1;
+
+/**
+ * File descriptor for accessing the keyboard LED:s
+ */
+static int ledfd = 0;
+
+/**
+ * Saved LED states
+ */
+static int saved_leds;
+
+/**
+ * Saved TTY settings
+ */
+static struct termios saved_stty;
+
+/**
+ * Save keyboard mode
+ */
+static int saved_kbd_mode;
+
+
+
+
+/**
+ * This function will be invoked before `initialise_server` (if not re-exec:ing)
+ * or before `unmarshal_server` (if re-exec:ing)
+ * 
+ * @return  Non-zero on error
+ */
+int __attribute__((const)) preinitialise_server(void)
+{
+  return 0;
+}
+
+
+/**
+ * This function should initialise the server,
+ * and it not invoked after a re-exec.
+ * 
+ * @return  Non-zero on error
+ */
+int initialise_server(void)
+{
+  int stage = 0;
+  const char* const message =
+    "Command: intercept\n"
+    "Message ID: 0\n"
+    "Length: 18\n"
+    "\n"
+    "Command: keyboard\n";
+  
+  if (full_send(message, strlen(message)))
+    return 1;
+  
+  open_leds();
+  stage = 1;
+  open_input();
+  stage = 2;
+  
+  fail_if (server_initialised());
+  stage = 0;
+  fail_if (mds_message_initialise(&received));
+  
+  return 0;
+  
+ pfail:
+  xperror(*argv);
+  if (stage >= 2)  close_input();
+  if (stage >= 1)  close_leds();
+  mds_message_destroy(&received);
+  return 1;
+}
+
+
+/**
+ * This function will be invoked after `initialise_server` (if not re-exec:ing)
+ * or after `unmarshal_server` (if re-exec:ing)
+ * 
+ * @return  Non-zero on error
+ */
+int postinitialise_server(void)
+{
+  if (connected)
+    return 0;
+  
+  if (reconnect_to_display())
+    {
+      mds_message_destroy(&received);
+      return 1;
+    }
+  connected = 1;
+  return 0;
+}
+
+
+/**
+ * This function is called by the parent server process when the
+ * child server process exits, if the server has completed its
+ * initialisation
+ * 
+ * @param  status  The status the child died with
+ */
+void fork_cleanup(int status)
+{
+  (void) status;
+  close_input();
+  close_leds();
+}
+
+
+/**
+ * Calculate the number of bytes that will be stored by `marshal_server`
+ * 
+ * On failure the program should `abort()` or exit by other means.
+ * However it should not be possible for this function to fail.
+ * 
+ * @return  The number of bytes that will be stored by `marshal_server`
+ */
+size_t marshal_server_size(void)
+{
+  size_t rc = 5 * sizeof(int) + sizeof(int32_t) + sizeof(struct termios);
+  rc += mds_message_marshal_size(&received);
+  return rc;
+}
+
+
+/**
+ * Marshal server implementation specific data into a buffer
+ * 
+ * @param   state_buf  The buffer for the marshalled data
+ * @return             Non-zero on error
+ */
+int marshal_server(char* state_buf)
+{
+  buf_set_next(state_buf, int, MDS_KKBD_VARS_VERSION);
+  buf_set_next(state_buf, int, connected);
+  buf_set_next(state_buf, int32_t, message_id);
+  buf_set_next(state_buf, int, ledfd);
+  buf_set_next(state_buf, int, saved_leds);
+  buf_set_next(state_buf, struct termios, saved_stty);
+  buf_set_next(state_buf, int, saved_kbd_mode);
+  mds_message_marshal(&received, state_buf);
+  
+  mds_message_destroy(&received);
+  return 0;
+}
+
+
+/**
+ * Unmarshal server implementation specific data and update the servers state accordingly
+ * 
+ * On critical failure the program should `abort()` or exit by other means.
+ * That is, do not let `reexec_failure_recover` run successfully, if it unrecoverable
+ * error has occurred or one severe enough that it is better to simply respawn.
+ * 
+ * @param   state_buf  The marshalled data that as not been read already
+ * @return             Non-zero on error
+ */
+int unmarshal_server(char* state_buf)
+{
+  /* buf_get_next(state_buf, int, MDS_KKBDOARD_VARS_VERSION); */
+  buf_next(state_buf, int, 1);
+  buf_get_next(state_buf, int, connected);
+  buf_get_next(state_buf, int32_t, message_id);
+  buf_get_next(state_buf, int, ledfd);
+  buf_get_next(state_buf, int, saved_leds);
+  buf_get_next(state_buf, struct termios, saved_stty);
+  buf_get_next(state_buf, int, saved_kbd_mode);
+  fail_if (mds_message_unmarshal(&received, state_buf));
+  
+  return 0;
+ pfail:
+  xperror(*argv);
+  mds_message_destroy(&received);
+  abort(); /* We must abort on failure to not risk the keyboard
+	      getting stuck and freeze up the computer until
+	      someone ssh:es into it and kill the server. */
+  return -1;
+}
+
+
+/**
+ * Attempt to recover from a re-exec failure that has been
+ * detected after the server successfully updated it execution image
+ * 
+ * @return  Non-zero on error
+ */
+int __attribute__((const)) reexec_failure_recover(void)
+{
+  return -1;
+}
+
+
+/**
+ * Perform the server's mission
+ * 
+ * @return  Non-zero on error
+ */
+int master_loop(void)
+{
+  int rc = 1;
+  int c, keycode, released;
+  int scancode[3];
+  
+  while ((c = getchar()) != 1) /* Exit with ESCAPE */
+    {
+    redo:
+      keycode = c & 0x7F;
+      released = !!(c & 0x80);
+      scancode[0] = keycode;
+      
+      if (keycode == 0)
+	{
+	  scancode[1] = getchar();
+	  if ((scancode[1] & 0x80) == 0)
+	    {
+	      c = scancode[1];
+	      goto redo;
+	    }
+	  scancode[2] = getchar();
+	  if ((scancode[2] & 0x80) == 0)
+	    {
+	      printf("scancode: %i\n", scancode[1]);
+	      printf("keycode: %i\n", scancode[1]);
+	      printf("released: no\n");
+	      c = scancode[2];
+	      goto redo;
+	    }
+	  keycode = (scancode[1] & 0x7F) << 7;
+	  keycode |= (scancode[2] & 0x7F);
+	  printf("scancode: %i %i %i\n",
+		 scancode[0], scancode[1], scancode[2]);
+	}
+      else
+	printf("scancode: %i\n", scancode[0]);
+      printf("keycode: %i\n", keycode);
+      printf("released: %s\n", released ? "yes" : "no");
+    }
+  
+  /*
+  while (!reexecing && !terminating)
+    {
+      int r = mds_message_read(&received, socket_fd);
+      if (r == 0)
+	{
+	  if (r = 0, r == 0) \/* TODO handle_message() *\/
+	    continue;
+	}
+      
+      if (r == -2)
+	{
+	  eprint("corrupt message received, aborting.");
+	  goto fail;
+	}
+      else if (errno == EINTR)
+	continue;
+      else if (errno != ECONNRESET)
+	goto pfail;
+      
+      eprint("lost connection to server.");
+      mds_message_destroy(&received);
+      mds_message_initialise(&received);
+      connected = 0;
+      if (reconnect_to_display())
+	goto fail;
+      connected = 1;
+    }
+  */
+  
+  rc = 0;
+  goto fail;
+ pfail:
+  xperror(*argv);
+ fail:
+  if (!rc && reexecing)
+    return 0;
+  mds_message_destroy(&received);
+  return rc;
+}
+
+
+/**
+ * Send a full message even if interrupted
+ * 
+ * @param   message  The message to send
+ * @param   length   The length of the message
+ * @return           Non-zero on success
+ */
+int full_send(const char* message, size_t length)
+{
+  size_t sent;
+  
+  while (length > 0)
+    {
+      sent = send_message(socket_fd, message, length);
+      if (sent > length)
+	{
+	  eprint("Sent more of a message than exists in the message, aborting.");
+	  return -1;
+	}
+      else if ((sent < length) && (errno != EINTR))
+	{
+	  xperror(*argv);
+	  return -1;
+	}
+      message += sent;
+      length -= sent;
+    }
+  return 0;
+}
+
+
+/**
+ * Acquire access of the keyboard's LED:s
+ * 
+ * @return  Zero on success, -1 on error
+ */
+int open_leds(void)
+{
+#ifdef __sparc__
+  if ((ledfd = open(SPARC_KBD, O_RDONLY)) < 0)
+    return -1;
+  if (ioctl(ledfd, GET_LED, &saved_leds) < 0)
+    {
+      close(ledfd);
+      return -1;
+    }
+  return 0;
+#else
+  return ioctl(ledfd, GET_LED, &saved_leds);
+#endif
+}
+
+
+/**
+ * Release access of the keyboard's LED:s
+ */
+void close_leds(void)
+{
+  if (ioctl(ledfd, SET_LED, saved_leds) < 0)
+    xperror(*argv);
+#ifdef __sparc__
+  close(ledfd);
+#endif
+}
+
+
+/**
+ * Get active LED:s on the keyboard
+ * 
+ * @return  Active LED:s, -1 on error
+ */
+int get_leds(void)
+{
+  int leds;
+  if (ioctl(ledfd, GET_LED, &leds) < 0)
+    return -1;
+#ifdef __sparc__
+  leds &= 15;
+#endif
+  return leds;
+}
+
+
+/**
+ * Set active LED:s on the keyboard
+ * 
+ * @param   leds  Active LED:s
+ * @return        Zero on success, -1 on error
+ */
+int set_leds(int leds)
+{
+  return ioctl(ledfd, SET_LED, leds);
+}
+
+
+/**
+ * Acquire access of keyboard input
+ * 
+ * @return  Zero on success, -1 on error
+ */
+int open_input(void)
+{
+  struct termios stty;
+  if (tcgetattr(STDIN_FILENO, &saved_stty) < 0)
+    return -1;
+  stty = saved_stty;
+  stty.c_lflag &= (tcflag_t)~(ECHO | ICANON | ISIG);
+  stty.c_iflag = 0;
+  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty) < 0)
+    return -1;
+  /* K_MEDIUMRAW: utilise keyboard drivers, but not layout */
+  if ((ioctl(STDIN_FILENO, KDGKBMODE, &saved_kbd_mode) < 0) ||
+      (ioctl(STDIN_FILENO, KDSKBMODE, K_MEDIUMRAW) < 0))
+    {
+      xperror(*argv);
+      return tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty);
+    }
+  return 0;
+}
+
+
+/**
+ * Release access of keyboard input
+ */
+void close_input(void)
+{
+  if (ioctl(STDIN_FILENO, KDSKBMODE, saved_kbd_mode) < 0)
+    xperror(*argv);
+  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty) < 0)
+    xperror(*argv);
+}
+
+
+/* TODO delay and repetition */
+
diff --git a/src/mds-kkbd.h b/src/mds-kkbd.h
new file mode 100644
index 0000000..fc22f2b
--- /dev/null
+++ b/src/mds-kkbd.h
@@ -0,0 +1,75 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef MDS_MDS_KKBD_H
+#define MDS_MDS_KKBD_H
+
+
+#include "mds-base.h"
+
+
+/**
+ * Send a full message even if interrupted
+ * 
+ * @param   message  The message to send
+ * @param   length   The length of the message
+ * @return           Non-zero on success
+ */
+int full_send(const char* message, size_t length);
+
+/**
+ * Acquire access of the keyboard's LED:s
+ * 
+ * @return  Zero on success, -1 on error
+ */
+int open_leds(void);
+
+/**
+ * Release access of the keyboard's LED:s
+ */
+void close_leds(void);
+
+/**
+ * Get active LED:s on the keyboard
+ * 
+ * @return  Active LED:s, -1 on error
+ */
+int get_leds(void);
+
+/**
+ * Set active LED:s on the keyboard
+ * 
+ * @param   leds  Active LED:s
+ * @return        Zero on success, -1 on error
+ */
+int set_leds(int leds);
+
+/**
+ * Acquire access of keyboard input
+ * 
+ * @return  Zero on success, -1 on error
+ */
+int open_input(void);
+
+/**
+ * Release access of keyboard input
+ */
+void close_input(void);
+
+
+#endif
+
diff --git a/src/mds-registry/mds-registry.c b/src/mds-registry/mds-registry.c
index 957310e..baefee7 100644
--- a/src/mds-registry/mds-registry.c
+++ b/src/mds-registry/mds-registry.c
@@ -42,7 +42,8 @@ server_characteristics_t server_characteristics =
     .require_privileges = 0,
     .require_display = 1,
     .require_respawn_info = 0,
-    .sanity_check_argc = 1
+    .sanity_check_argc = 1,
+    .fork_for_safety = 0
   };
 
 
@@ -111,7 +112,7 @@ int initialise_server(void)
     }
   reg_table.key_comparator = (compare_func*)string_comparator;
   reg_table.hasher = (hash_func*)string_hash;
-  server_initialised();
+  fail_if (server_initialised() < 0);
   fail_if (mds_message_initialise(&received));
   
   return 0;  
diff --git a/src/mds-respawn.c b/src/mds-respawn.c
index 24084f0..ebe8411 100644
--- a/src/mds-respawn.c
+++ b/src/mds-respawn.c
@@ -46,7 +46,8 @@ server_characteristics_t server_characteristics =
     .require_privileges = 0,
     .require_display = 0,
     .require_respawn_info = 1,
-    .sanity_check_argc = 0
+    .sanity_check_argc = 0,
+    .fork_for_safety = 0
   };
 
 
@@ -508,7 +509,7 @@ int master_loop(void)
   
   while (!reexecing && !terminating && live_count)
     {
-      pid_t pid = waitpid(-1, &status, 0);
+      pid_t pid = uninterruptable_waitpid(-1, &status, 0);
       
       if (reviving)
 	for (reviving = 0, i = 0; i < servers; i++)
@@ -517,8 +518,6 @@ int master_loop(void)
       
       if (pid == (pid_t)-1)
 	{
-	  if (errno == EINTR)
-	    continue;
 	  xperror(*argv);
 	  rc = 1;
 	  break;
diff --git a/src/mds-server/mds-server.c b/src/mds-server/mds-server.c
index 46451a0..b217f2b 100644
--- a/src/mds-server/mds-server.c
+++ b/src/mds-server/mds-server.c
@@ -56,7 +56,8 @@ server_characteristics_t server_characteristics =
     .require_privileges = 0,
     .require_display = 0, /* We will service one ourself. */
     .require_respawn_info = 1,
-    .sanity_check_argc = 1
+    .sanity_check_argc = 1,
+    .fork_for_safety = 0
   };
 
 
diff --git a/src/mds.c b/src/mds.c
index 5a204f6..cb8e657 100644
--- a/src/mds.c
+++ b/src/mds.c
@@ -336,7 +336,7 @@ int spawn_and_respawn_server(int fd)
     perror(*argv);
   
   /* Wait for master server to die. */
-  if (waitpid(pid, &status, 0) == (pid_t)-1)
+  if (uninterruptable_waitpid(pid, &status, 0) == (pid_t)-1)
     goto pfail;
   
   /* If the server exited normally or SIGTERM, do not respawn. */