src/core/killall.c

	killall.c revision ccd06097c79218f7d5ea4c21721bbcbc7c467dca
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering/***
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  This file is part of systemd.
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  Copyright 2010 ProFUSION embedded systems
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  systemd is free software; you can redistribute it and/or modify it
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  under the terms of the GNU Lesser General Public License as published by
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  the Free Software Foundation; either version 2.1 of the License, or
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  (at your option) any later version.
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  systemd is distributed in the hope that it will be useful, but
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  WITHOUT ANY WARRANTY; without even the implied warranty of
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  Lesser General Public License for more details.
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  You should have received a copy of the GNU Lesser General Public License
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering  along with systemd; If not, see <http://www.gnu.org/licenses/>.
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering***/
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include <sys/wait.h>
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include <signal.h>
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include <errno.h>
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include <unistd.h>
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include "util.h"
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include "def.h"
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include "killall.h"
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#include "set.h"
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering#define TIMEOUT_USEC (10 * USEC_PER_SEC)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poetteringstatic bool ignore_proc(pid_t pid) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        _cleanup_fclose_ FILE *f = NULL;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        char c, *p;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        size_t count;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        uid_t uid;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        int r;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        /* We are PID 1, let's not commit suicide */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (pid == 1)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return true;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        r = get_process_uid(pid, &uid);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (r < 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return true; /* not really, but better safe than sorry */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        /* Non-root processes otherwise are always subject to be killed */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (uid != 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return false;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        p = procfs_file_alloca(pid, "cmdline");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        f = fopen(p, "re");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (!f)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return true; /* not really, but has the desired effect */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        count = fread(&c, 1, 1, f);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        /* Kernel threads have an empty cmdline */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (count <= 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return true;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        /* Processes with argv[0][0] = '@' we ignore from the killing
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering         * spree.
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering         *
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering         * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (count == 1 && c == '@')
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return true;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        return false;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering}
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poetteringstatic void wait_for_children(Set *pids, sigset_t *mask) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        usec_t until;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        assert(mask);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (set_isempty(pids))
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        for (;;) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                struct timespec ts;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                int k;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                usec_t n;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                void *p;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                Iterator i;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                /* First, let the kernel inform us about killed
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                 * children. Most processes will probably be our
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                 * children, but some are not (might be our
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                 * grandchildren instead...). */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                for (;;) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        pid_t pid;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        pid = waitpid(-1, NULL, WNOHANG);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (pid == 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                break;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (pid < 0) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                if (errno == ECHILD)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                        break;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                log_error("waitpid() failed: %m");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                return;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        set_remove(pids, ULONG_TO_PTR(pid));
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                /* Now explicitly check who might be remaining, who
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                 * might not be our child. */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                SET_FOREACH(p, pids, i) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        /* We misuse getpgid as a check whether a
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                         * process still exists. */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (getpgid((pid_t) PTR_TO_ULONG(p)) >= 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                continue;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (errno != ESRCH)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                continue;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        set_remove(pids, p);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (set_isempty(pids))
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        return;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                n = now(CLOCK_MONOTONIC);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (n >= until)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        return;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                timespec_store(&ts, until - n);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                k = sigtimedwait(mask, NULL, &ts);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (k != SIGCHLD) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (k < 0 && errno != EAGAIN) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                log_error("sigtimedwait() failed: %m");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                return;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (k >= 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                log_warning("sigtimedwait() returned unexpected signal.");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering}
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poetteringstatic int killall(int sig, Set *pids, bool send_sighup) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        _cleanup_closedir_ DIR *dir = NULL;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        struct dirent *d;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        dir = opendir("/proc");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (!dir)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                return -errno;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        while ((d = readdir(dir))) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                pid_t pid;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (d->d_type != DT_DIR &&
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                    d->d_type != DT_UNKNOWN)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        continue;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (parse_pid(d->d_name, &pid) < 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        continue;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (ignore_proc(pid))
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        continue;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (sig == SIGKILL) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        _cleanup_free_ char *s;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        get_process_comm(pid, &s);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s));
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (kill(pid, sig) >= 0) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (pids)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                set_put(pids, ULONG_TO_PTR(pid));
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                } else if (errno != ENOENT)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        log_warning("Could not kill %d: %m", pid);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                if (send_sighup) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        /* Optionally, also send a SIGHUP signal, but
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        only if the process has a controlling
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        tty. This is useful to allow handling of
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        shells which ignore SIGTERM but react to
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        SIGHUP. We do not send this to processes that
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        have no controlling TTY since we don't want to
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        trigger reloads of daemon processes. Also we
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        make sure to only send this after SIGTERM so
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        that SIGTERM is always first in the queue. */
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                        if (get_ctty_devnr(pid, NULL) >= 0)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                                kill(pid, SIGHUP);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        }
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        return set_size(pids);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering}
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poetteringvoid broadcast_signal(int sig, bool wait_for_exit, bool send_sighup) {
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        sigset_t mask, oldmask;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        Set *pids = NULL;
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (wait_for_exit)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                pids = set_new(trivial_hash_func, trivial_compare_func);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        assert_se(sigemptyset(&mask) == 0);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        assert_se(sigaddset(&mask, SIGCHLD) == 0);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                log_warning("kill(-1, SIGSTOP) failed: %m");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        killall(sig, pids, send_sighup);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                log_warning("kill(-1, SIGCONT) failed: %m");
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        if (wait_for_exit)
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering                wait_for_children(pids, &mask);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering        set_free(pids);
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering}
72648326ea6d3e68cdb0b5890df737047d031a41Lennart Poettering