2a96a552f9
This reverts commit a59629fcc6.
This is not needed anymore because the IOThread mutex is not
"magic" anymore (need not kick the CPU thread)and also because
fork callbacks are only enabled at the very beginning of
QEMU's execution.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
339 lines
8.0 KiB
C
339 lines
8.0 KiB
C
/*
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* os-posix.c
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*
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* Copyright (c) 2003-2008 Fabrice Bellard
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* Copyright (c) 2010 Red Hat, Inc.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include <sys/wait.h>
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/*needed for MAP_POPULATE before including qemu-options.h */
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#include <pwd.h>
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#include <grp.h>
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#include <libgen.h>
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/* Needed early for CONFIG_BSD etc. */
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#include "sysemu/sysemu.h"
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#include "net/slirp.h"
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#include "qemu-options.h"
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#include "qemu/error-report.h"
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#include "qemu/log.h"
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#include "qemu/cutils.h"
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#ifdef CONFIG_LINUX
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#include <sys/prctl.h>
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#endif
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static struct passwd *user_pwd;
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static const char *chroot_dir;
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static int daemonize;
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static int daemon_pipe;
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void os_setup_early_signal_handling(void)
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{
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struct sigaction act;
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sigfillset(&act.sa_mask);
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act.sa_flags = 0;
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act.sa_handler = SIG_IGN;
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sigaction(SIGPIPE, &act, NULL);
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}
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static void termsig_handler(int signal, siginfo_t *info, void *c)
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{
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qemu_system_killed(info->si_signo, info->si_pid);
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}
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void os_setup_signal_handling(void)
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{
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struct sigaction act;
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memset(&act, 0, sizeof(act));
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act.sa_sigaction = termsig_handler;
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act.sa_flags = SA_SIGINFO;
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sigaction(SIGINT, &act, NULL);
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sigaction(SIGHUP, &act, NULL);
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sigaction(SIGTERM, &act, NULL);
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}
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/* Find a likely location for support files using the location of the binary.
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For installed binaries this will be "$bindir/../share/qemu". When
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running from the build tree this will be "$bindir/../pc-bios". */
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#define SHARE_SUFFIX "/share/qemu"
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#define BUILD_SUFFIX "/pc-bios"
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char *os_find_datadir(void)
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{
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char *dir, *exec_dir;
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char *res;
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size_t max_len;
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exec_dir = qemu_get_exec_dir();
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if (exec_dir == NULL) {
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return NULL;
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}
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dir = g_path_get_dirname(exec_dir);
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max_len = strlen(dir) +
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MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
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res = g_malloc0(max_len);
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snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
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if (access(res, R_OK)) {
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snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
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if (access(res, R_OK)) {
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g_free(res);
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res = NULL;
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}
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}
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g_free(dir);
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g_free(exec_dir);
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return res;
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}
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#undef SHARE_SUFFIX
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#undef BUILD_SUFFIX
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void os_set_proc_name(const char *s)
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{
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#if defined(PR_SET_NAME)
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char name[16];
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if (!s)
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return;
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pstrcpy(name, sizeof(name), s);
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/* Could rewrite argv[0] too, but that's a bit more complicated.
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This simple way is enough for `top'. */
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if (prctl(PR_SET_NAME, name)) {
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perror("unable to change process name");
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exit(1);
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}
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#else
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fprintf(stderr, "Change of process name not supported by your OS\n");
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exit(1);
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#endif
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}
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/*
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* Parse OS specific command line options.
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* return 0 if option handled, -1 otherwise
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*/
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void os_parse_cmd_args(int index, const char *optarg)
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{
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switch (index) {
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#ifdef CONFIG_SLIRP
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case QEMU_OPTION_smb:
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error_report("The -smb option is deprecated. "
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"Please use '-netdev user,smb=...' instead.");
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if (net_slirp_smb(optarg) < 0)
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exit(1);
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break;
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#endif
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case QEMU_OPTION_runas:
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user_pwd = getpwnam(optarg);
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if (!user_pwd) {
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fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
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exit(1);
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}
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break;
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case QEMU_OPTION_chroot:
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chroot_dir = optarg;
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break;
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case QEMU_OPTION_daemonize:
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daemonize = 1;
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break;
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#if defined(CONFIG_LINUX)
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case QEMU_OPTION_enablefips:
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fips_set_state(true);
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break;
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#endif
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}
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}
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static void change_process_uid(void)
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{
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if (user_pwd) {
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if (setgid(user_pwd->pw_gid) < 0) {
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fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
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exit(1);
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}
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if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
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fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
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user_pwd->pw_name, user_pwd->pw_gid);
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exit(1);
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}
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if (setuid(user_pwd->pw_uid) < 0) {
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fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
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exit(1);
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}
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if (setuid(0) != -1) {
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fprintf(stderr, "Dropping privileges failed\n");
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exit(1);
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}
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}
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}
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static void change_root(void)
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{
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if (chroot_dir) {
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if (chroot(chroot_dir) < 0) {
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fprintf(stderr, "chroot failed\n");
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exit(1);
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}
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if (chdir("/")) {
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perror("not able to chdir to /");
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exit(1);
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}
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}
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}
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void os_daemonize(void)
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{
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if (daemonize) {
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pid_t pid;
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int fds[2];
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if (pipe(fds) == -1) {
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exit(1);
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}
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pid = fork();
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if (pid > 0) {
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uint8_t status;
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ssize_t len;
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close(fds[1]);
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do {
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len = read(fds[0], &status, 1);
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} while (len < 0 && errno == EINTR);
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/* only exit successfully if our child actually wrote
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* a one-byte zero to our pipe, upon successful init */
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exit(len == 1 && status == 0 ? 0 : 1);
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} else if (pid < 0) {
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exit(1);
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}
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close(fds[0]);
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daemon_pipe = fds[1];
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qemu_set_cloexec(daemon_pipe);
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setsid();
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pid = fork();
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if (pid > 0) {
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exit(0);
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} else if (pid < 0) {
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exit(1);
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}
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umask(027);
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signal(SIGTSTP, SIG_IGN);
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signal(SIGTTOU, SIG_IGN);
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signal(SIGTTIN, SIG_IGN);
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}
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}
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void os_setup_post(void)
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{
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int fd = 0;
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if (daemonize) {
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if (chdir("/")) {
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perror("not able to chdir to /");
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exit(1);
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}
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TFR(fd = qemu_open("/dev/null", O_RDWR));
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if (fd == -1) {
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exit(1);
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}
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}
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change_root();
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change_process_uid();
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if (daemonize) {
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uint8_t status = 0;
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ssize_t len;
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dup2(fd, 0);
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dup2(fd, 1);
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/* In case -D is given do not redirect stderr to /dev/null */
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if (!qemu_logfile) {
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dup2(fd, 2);
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}
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close(fd);
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do {
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len = write(daemon_pipe, &status, 1);
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} while (len < 0 && errno == EINTR);
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if (len != 1) {
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exit(1);
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}
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}
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}
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void os_set_line_buffering(void)
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{
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setvbuf(stdout, NULL, _IOLBF, 0);
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}
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int qemu_create_pidfile(const char *filename)
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{
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char buffer[128];
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int len;
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int fd;
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fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
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if (fd == -1) {
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return -1;
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}
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if (lockf(fd, F_TLOCK, 0) == -1) {
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close(fd);
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return -1;
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}
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len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
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if (write(fd, buffer, len) != len) {
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close(fd);
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return -1;
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}
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/* keep pidfile open & locked forever */
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return 0;
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}
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bool is_daemonized(void)
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{
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return daemonize;
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}
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int os_mlock(void)
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{
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int ret = 0;
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ret = mlockall(MCL_CURRENT | MCL_FUTURE);
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if (ret < 0) {
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perror("mlockall");
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}
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return ret;
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}
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