X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshutdown.c;h=cd478b0349901e6a8762bea0adcc6f8adc190f73;hb=68fb08920b2162b48cf0fa8dd98b021327b42896;hp=a2f3b539b3023dffbfa589337c9f296eef63aa25;hpb=f41de9596627ef68fcb4c0dae4b9bd8033701230;p=elogind.git

diff --git a/src/shutdown.c b/src/shutdown.c
index a2f3b539b..cd478b034 100644
--- a/src/shutdown.c
+++ b/src/shutdown.c
@@ -6,16 +6,16 @@
   Copyright 2010 ProFUSION embedded systems
 
   systemd 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 2 of the License, or
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.
 
   systemd 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.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
@@ -24,6 +24,11 @@
 #include <sys/reboot.h>
 #include <linux/reboot.h>
 #include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <sys/syscall.h>
+#include <fcntl.h>
 #include <dirent.h>
 #include <errno.h>
 #include <unistd.h>
@@ -32,37 +37,59 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "missing.h"
 #include "log.h"
 #include "umount.h"
 #include "util.h"
+#include "mkdir.h"
+#include "virt.h"
+#include "watchdog.h"
 
 #define TIMEOUT_USEC (5 * USEC_PER_SEC)
 #define FINALIZE_ATTEMPTS 50
 
 static bool ignore_proc(pid_t pid) {
+        char buf[PATH_MAX];
+        FILE *f;
+        char c;
+        size_t count;
+        uid_t uid;
+        int r;
+
+        /* We are PID 1, let's not commit suicide */
         if (pid == 1)
                 return true;
 
-        /* TODO: add more ignore rules here: device-mapper, etc */
+        r = get_process_uid(pid, &uid);
+        if (r < 0)
+                return true; /* not really, but better safe than sorry */
 
-        return false;
-}
+        /* Non-root processes otherwise are always subject to be killed */
+        if (uid != 0)
+                return false;
 
-static bool is_kernel_thread(pid_t pid)
-{
-        char buf[PATH_MAX];
-        FILE *f;
-        char c;
-        size_t count;
+        snprintf(buf, sizeof(buf), "/proc/%lu/cmdline", (unsigned long) pid);
+        char_array_0(buf);
 
-        snprintf(buf, sizeof(buf), "/proc/%lu/cmdline", (unsigned long)pid);
         f = fopen(buf, "re");
         if (!f)
                 return true; /* not really, but has the desired effect */
 
         count = fread(&c, 1, 1, f);
         fclose(f);
-        return count != 1;
+
+        /* Kernel threads have an empty cmdline */
+        if (count <= 0)
+                return true;
+
+        /* Processes with argv[0][0] = '@' we ignore from the killing
+         * spree.
+         *
+         * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
+        if (count == 1 && c == '@')
+                return true;
+
+        return false;
 }
 
 static int killall(int sign) {
@@ -70,7 +97,8 @@ static int killall(int sign) {
         struct dirent *d;
         unsigned int n_processes = 0;
 
-        if ((dir = opendir("/proc")) == NULL)
+        dir = opendir("/proc");
+        if (!dir)
                 return -errno;
 
         while ((d = readdir(dir))) {
@@ -79,9 +107,6 @@ static int killall(int sign) {
                 if (parse_pid(d->d_name, &pid) < 0)
                         continue;
 
-                if (is_kernel_thread(pid))
-                        continue;
-
                 if (ignore_proc(pid))
                         continue;
 
@@ -192,16 +217,105 @@ finish:
         sigprocmask(SIG_SETMASK, &oldmask, NULL);
 }
 
+static int prepare_new_root(void) {
+        static const char dirs[] =
+                "/run/initramfs/oldroot\0"
+                "/run/initramfs/proc\0"
+                "/run/initramfs/sys\0"
+                "/run/initramfs/dev\0"
+                "/run/initramfs/run\0";
+
+        const char *dir;
+
+        if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) {
+                log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m");
+                return -errno;
+        }
+
+        if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) {
+                log_error("Failed to make /run/initramfs private mount: %m");
+                return -errno;
+        }
+
+        NULSTR_FOREACH(dir, dirs)
+                if (mkdir_p(dir, 0755) < 0 && errno != EEXIST) {
+                        log_error("Failed to mkdir %s: %m", dir);
+                        return -errno;
+                }
+
+        if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) {
+                log_error("Failed to mount bind /sys on /run/initramfs/sys: %m");
+                return -errno;
+        }
+
+        if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) {
+                log_error("Failed to mount bind /proc on /run/initramfs/proc: %m");
+                return -errno;
+        }
+
+        if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) {
+                log_error("Failed to mount bind /dev on /run/initramfs/dev: %m");
+                return -errno;
+        }
+
+        if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) {
+                log_error("Failed to mount bind /run on /run/initramfs/run: %m");
+                return -errno;
+        }
+
+        return 0;
+}
+
+static int pivot_to_new_root(void) {
+        int fd;
+
+        chdir("/run/initramfs");
+
+        /*
+          In case some evil process made "/" MS_SHARED
+          It works for pivot_root, but the ref count for the root device
+          is not decreasing :-/
+        */
+        if (mount(NULL, "/", NULL, MS_PRIVATE, NULL) < 0) {
+                log_error("Failed to make \"/\" private mount %m");
+                return -errno;
+        }
+
+        if (pivot_root(".", "oldroot") < 0) {
+                log_error("pivot failed: %m");
+                /* only chroot if pivot root succeded */
+                return -errno;
+        }
+
+        chroot(".");
+        log_info("Successfully changed into root pivot.");
+
+        fd = open("/dev/console", O_RDWR);
+        if (fd < 0)
+                log_error("Failed to open /dev/console: %m");
+        else {
+                make_stdio(fd);
+
+                /* Initialize the controlling terminal */
+                setsid();
+                ioctl(STDIN_FILENO, TIOCSCTTY, NULL);
+        }
+
+        return 0;
+}
+
 int main(int argc, char *argv[]) {
         int cmd, r;
         unsigned retries;
         bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
-        bool killed_everbody = false, in_container;
+        bool killed_everbody = false, in_container, use_watchdog = false;
 
         log_parse_environment();
         log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */
         log_open();
 
+        umask(0022);
+
         if (getpid() != 1) {
                 log_error("Not executed by init (pid 1).");
                 r = -EPERM;
@@ -230,6 +344,8 @@ int main(int argc, char *argv[]) {
                 goto error;
         }
 
+        use_watchdog = !!getenv("WATCHDOG_USEC");
+
         /* lock us into memory */
         if (mlockall(MCL_CURRENT|MCL_FUTURE) != 0)
                 log_warning("Cannot lock process memory: %m");
@@ -247,6 +363,9 @@ int main(int argc, char *argv[]) {
         for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
                 bool changed = false;
 
+                if (use_watchdog)
+                        watchdog_ping();
+
                 if (need_umount) {
                         log_info("Unmounting file systems.");
                         r = umount_all(&changed);
@@ -291,9 +410,12 @@ int main(int argc, char *argv[]) {
                                 log_error("Failed to detach DM devices: %s", strerror(-r));
                 }
 
-                if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach)
+                if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) {
+                        if (retries > 0)
+                                log_info("All filesystems, swaps, loop devices, DM devices detached.");
                         /* Yay, done */
                         break;
+                }
 
                 /* If in this iteration we didn't manage to
                  * unmount/deactivate anything, we either kill more
@@ -328,6 +450,15 @@ int main(int argc, char *argv[]) {
                 exit(0);
         }
 
+        if (access("/run/initramfs/shutdown", X_OK) == 0) {
+
+                if (prepare_new_root() >= 0 &&
+                    pivot_to_new_root() >= 0) {
+                        execv("/shutdown", argv);
+                        log_error("Failed to execute shutdown binary: %m");
+                }
+        }
+
         sync();
 
         if (cmd == LINUX_REBOOT_CMD_KEXEC) {