X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshutdown.c;h=d157e0fbfeaf4db91cea33666f9e2ab5c59c3633;hb=6ef25fb65ee0a62972ed7cbc01b6a11feb5fcb16;hp=a2f3b539b3023dffbfa589337c9f296eef63aa25;hpb=f41de9596627ef68fcb4c0dae4b9bd8033701230;p=elogind.git diff --git a/src/shutdown.c b/src/shutdown.c index a2f3b539b..d157e0fbf 100644 --- a/src/shutdown.c +++ b/src/shutdown.c @@ -24,6 +24,11 @@ #include #include #include +#include +#include +#include +#include +#include #include #include #include @@ -32,37 +37,57 @@ #include #include +#include "missing.h" #include "log.h" #include "umount.h" #include "util.h" +#include "virt.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 +95,8 @@ 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 +105,6 @@ 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; @@ -192,6 +215,93 @@ 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; @@ -202,6 +312,8 @@ int main(int argc, char *argv[]) { 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; @@ -291,9 +403,12 @@ 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 +443,15 @@ 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) {