source: branches/stable/mindi-busybox/libbb/vfork_daemon_rexec.c @ 1770

Last change on this file since 1770 was 1770, checked in by Bruno Cornec, 13 years ago
  • Better output for mindi-busybox revision
  • Remove dummy file created on NFS - report from Arnaud Tiger <arnaud.tiger_at_hp.com>
  • strace useful for debug
  • fix new versions for pb (2.0.0 for mindi and 1.7.2 for mindi-busybox)
  • fix build process for mindi-busybox + options used in that version (dd for label-partitions-as-necessary)
  • fix typo in label-partitions-as-necessary which doesn't seem to work
  • Update to busybox 1.7.2
  • perl is now required at restore time to support uuid swap partitions (and will be used for many other thigs

in the future for sure)

  • next mindi version will be 2.0.0 due to all the changes made in it (udev may break working distros)
  • small optimization in mindi on keyboard handling (one single find instead of multiple)
  • better interaction for USB device when launching mindi manually
  • attempt to automatically guess block disk size for ramdisk
  • fix typos in bkphw
  • Fix the remaining problem with UUID support for swap partitions
  • Updates mondoarchive man page for USB support
  • Adds preliminary Hardware support to mindi (Proliant SSSTK)
  • Tries to add udev support also for rhel4
  • Fix UUID support which was still broken.
  • Be conservative in test for the start-nfs script
  • Update config file for mindi-busybox for 1.7.2 migration
  • Try to run around a busybox bug (1.2.2 pb on inexistant links)
  • Add build content for mindi-busybox in pb
  • Remove distributions content for mindi-busybox
  • Fix a warning on inexistant raidtab
  • Solve problem on tmpfs in restore init (Problem of inexistant symlink and busybox)
  • Create MONDO_CACHE and use it everywhere + creation at start
  • Really never try to eject a USB device
  • Fix a issue with &> usage (replaced with 1> and 2>)
  • Adds magic file to depllist in order to have file working + ldd which helps for debugging issues
  • tty modes correct to avoid sh error messages
  • Use ext3 normally and not ext2 instead
  • USB device should be corrected after reading (take 1st part)
  • Adds a mount_USB_here function derived from mount_CDROM_here
  • usb detection place before /dev detection in device name at restore time
  • Fix when restoring from USB: media is asked in interactive mode
  • Adds USB support for mondorestore
  • mount_cdrom => mount_media
  • elilo.efi is now searched throughout /boot/efi and not in a fixed place as there is no standard
  • untar-and-softlink => untar (+ interface change)
  • suppress useless softlinks creation/removal in boot process
  • avoids udevd messages on groups
  • Increase # of disks to 99 as in mindi at restore time (should be a conf file parameter)
  • skip existing big file creation
  • seems to work correctly for USB mindi boot
  • Adds group and tty link to udev conf
  • Always load usb-torage (even 2.6) to initiate USB bus discovery
  • Better printing of messages
  • Attempt to fix a bug in supporting OpenSusE 10.3 kernel for initramfs (mindi may now use multiple regex for kernel initrd detection)
  • Links were not correctly done as non relative for modules in mindi
  • exclusion of modules denied now works
  • Also create modules in their ordinary place, so that classical modprobe works + copy modules.dep
  • Fix bugs for DENY_MODS handling
  • Add device /dev/console for udev
  • ide-generic should now really be excluded
  • Fix a bug in major number for tty
  • If udev then adds modprobe/insmod to rootfs
  • tty0 is also cretaed with udev
  • ide-generic put rather in DENY_MODS
  • udevd remove from deplist s handled in mindi directly
  • better default for mindi when using --usb
  • Handles dynamically linked busybox (in case we want to use it soon ;-)
  • Adds fixed devices to create for udev
  • ide-generic should not be part of the initrd when using libata v2
  • support a dynamically linked udev (case on Ubuntu 7.10 and Mandriva 2008.0 so should be quite generic) This will give incitation to move to dyn. linked binaries in the initrd which will help for other tasks (ia6 4)
  • Improvement in udev support (do not use cl options not available in busybox)
  • Udev in mindi
    • auto creation of the right links at boot time with udev-links.conf(from Mandriva 2008.0)
    • rework startup of udev as current makes kernel crash (from Mandriva 2008.0)
    • add support for 64 bits udev
  • Try to render MyInsmod? silent at boot time
  • Adds udev support (mandatory for newest distributions to avoid remapping of devices in a different way as on the original system)
  • We also need vaft format support for USB boot
  • Adds libusual support (Ubuntu 7.10 needs it for USB)
  • Improve Ubuntu/Debian? keyboard detection and support
  • pbinit adapted to new pb (0.8.10). Filtering of docs done in it
  • Suppress some mondo warnings and errors on USB again
  • Tries to fix lack of files in deb mindi package
  • Verify should now work for USB devices
  • More log/mesages improvement for USB support
  • - Supress g_erase_tmpdir_and_scratchdir
  • Improve some log messages for USB support
  • Try to improve install in mindi to avoid issues with isolinux.cfg not installed vene if in the pkg :-(
  • Improve mindi-busybox build
  • In conformity with pb 0.8.9
  • Add support for Ubuntu 7.10 in build process
  • Add USB Key button to Menu UI (CD streamer removed)
  • Attempt to fix error messages on tmp/scratch files at the end by removing those dir at the latest possible.
  • Fix a bug linked to the size of the -E param which could be used (Arnaud Tiger/René? Ribaud).
  • Integrate ~/.pbrc content into mondorescue.pb (required project-builder >= 0.8.7)
  • Put mondorescue in conformity with new pb filtering rules
  • Add USB support at restore time (no test done yet). New start-usb script PB varibale added where useful
  • Unmounting USB device before removal of temporary scratchdir
  • Stil refining USB copy back to mondo (one command was not executed)
  • No need to have the image subdor in the csratchdir when USB.
  • umount the USB partition before attempting to use it
  • Remove useless copy from mindi to mondo at end of USB handling

(risky merge, we are raising the limits of 2 diverging branches. The status of stable is not completely sure as such. Will need lots of tests, but it's not yet done :-()
(merge -r1692:1769 $SVN_M/branches/2.2.5)

File size: 6.4 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Rexec program for system have fork() as vfork() with foreground option
4 *
5 * Copyright (C) Vladimir N. Oleynik <dzo@simtreas.ru>
6 * Copyright (C) 2003 Russ Dill <Russ.Dill@asu.edu>
7 *
8 * daemon() portion taken from uClibc:
9 *
10 * Copyright (c) 1991, 1993
11 *      The Regents of the University of California.  All rights reserved.
12 *
13 * Modified for uClibc by Erik Andersen <andersee@debian.org>
14 *
15 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
16 */
17
18#include <paths.h>
19#include "busybox.h" /* for struct bb_applet */
20
21/* This does a fork/exec in one call, using vfork().  Returns PID of new child,
22 * -1 for failure.  Runs argv[0], searching path if that has no / in it. */
23pid_t spawn(char **argv)
24{
25    /* Compiler should not optimize stores here */
26    volatile int failed;
27    pid_t pid;
28
29// Ain't it a good place to fflush(NULL)?
30
31    /* Be nice to nommu machines. */
32    failed = 0;
33    pid = vfork();
34    if (pid < 0) /* error */
35        return pid;
36    if (!pid) { /* child */
37        /* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */
38        BB_EXECVP(argv[0], argv);
39
40        /* We are (maybe) sharing a stack with blocked parent,
41         * let parent know we failed and then exit to unblock parent
42         * (but don't run atexit() stuff, which would screw up parent.)
43         */
44        failed = errno;
45        _exit(111);
46    }
47    /* parent */
48    /* Unfortunately, this is not reliable: according to standards
49     * vfork() can be equivalent to fork() and we won't see value
50     * of 'failed'.
51     * Interested party can wait on pid and learn exit code.
52     * If 111 - then it (most probably) failed to exec */
53    if (failed) {
54        errno = failed;
55        return -1;
56    }
57    return pid;
58}
59
60/* Die with an error message if we can't spawn a child process. */
61pid_t xspawn(char **argv)
62{
63    pid_t pid = spawn(argv);
64    if (pid < 0)
65        bb_perror_msg_and_die("%s", *argv);
66    return pid;
67}
68
69// Wait for the specified child PID to exit, returning child's error return.
70int wait4pid(int pid)
71{
72    int status;
73
74    if (pid <= 0) {
75        /*errno = ECHILD; -- wrong. */
76        /* we expect errno to be already set from failed [v]fork/exec */
77        return -1;
78    }
79    if (waitpid(pid, &status, 0) == -1)
80        return -1;
81    if (WIFEXITED(status))
82        return WEXITSTATUS(status);
83    if (WIFSIGNALED(status))
84        return WTERMSIG(status) + 1000;
85    return 0;
86}
87
88int wait_nohang(int *wstat)
89{
90    return waitpid(-1, wstat, WNOHANG);
91}
92
93int wait_pid(int *wstat, int pid)
94{
95    int r;
96
97    do
98        r = waitpid(pid, wstat, 0);
99    while ((r == -1) && (errno == EINTR));
100    return r;
101}
102
103#if ENABLE_FEATURE_PREFER_APPLETS
104void save_nofork_data(struct nofork_save_area *save)
105{
106    memcpy(&save->die_jmp, &die_jmp, sizeof(die_jmp));
107    save->current_applet = current_applet;
108    save->xfunc_error_retval = xfunc_error_retval;
109    save->option_mask32 = option_mask32;
110    save->die_sleep = die_sleep;
111    save->saved = 1;
112}
113
114void restore_nofork_data(struct nofork_save_area *save)
115{
116    memcpy(&die_jmp, &save->die_jmp, sizeof(die_jmp));
117    current_applet = save->current_applet;
118    xfunc_error_retval = save->xfunc_error_retval;
119    option_mask32 = save->option_mask32;
120    die_sleep = save->die_sleep;
121
122    applet_name = current_applet->name;
123}
124
125int run_nofork_applet_prime(struct nofork_save_area *old, const struct bb_applet *a, char **argv)
126{
127    int rc, argc;
128
129    current_applet = a;
130    applet_name = a->name;
131    xfunc_error_retval = EXIT_FAILURE;
132    /*option_mask32 = 0; - not needed */
133    /* special flag for xfunc_die(). If xfunc will "die"
134     * in NOFORK applet, xfunc_die() sees negative
135     * die_sleep and longjmp here instead. */
136    die_sleep = -1;
137
138    argc = 1;
139    while (argv[argc])
140        argc++;
141
142    rc = setjmp(die_jmp);
143    if (!rc) {
144        /* Some callers (xargs)
145         * need argv untouched because they free argv[i]! */
146        char *tmp_argv[argc+1];
147        memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0]));
148        /* Finally we can call NOFORK applet's main() */
149        rc = a->main(argc, tmp_argv);
150    } else { /* xfunc died in NOFORK applet */
151        /* in case they meant to return 0... */
152        if (rc == -2222)
153            rc = 0;
154    }
155
156    /* Restoring globals */
157    restore_nofork_data(old);
158    return rc;
159}
160
161int run_nofork_applet(const struct bb_applet *a, char **argv)
162{
163    struct nofork_save_area old;
164
165    /* Saving globals */
166    save_nofork_data(&old);
167    return run_nofork_applet_prime(&old, a, argv);
168}
169#endif /* FEATURE_PREFER_APPLETS */
170
171int spawn_and_wait(char **argv)
172{
173    int rc;
174#if ENABLE_FEATURE_PREFER_APPLETS
175    const struct bb_applet *a = find_applet_by_name(argv[0]);
176
177    if (a && (a->nofork
178#if BB_MMU
179         || a->noexec /* NOEXEC trick needs fork() */
180#endif
181    )) {
182#if BB_MMU
183        if (a->nofork)
184#endif
185        {
186            return run_nofork_applet(a, argv);
187        }
188#if BB_MMU
189        /* MMU only */
190        /* a->noexec is true */
191        rc = fork();
192        if (rc) /* parent or error */
193            return wait4pid(rc);
194        /* child */
195        xfunc_error_retval = EXIT_FAILURE;
196        current_applet = a;
197        run_current_applet_and_exit(argv);
198#endif
199    }
200#endif /* FEATURE_PREFER_APPLETS */
201    rc = spawn(argv);
202    return wait4pid(rc);
203}
204
205#if !BB_MMU
206void re_exec(char **argv)
207{
208    /* high-order bit of first char in argv[0] is a hidden
209     * "we have (already) re-execed, don't do it again" flag */
210    argv[0][0] |= 0x80;
211    execv(bb_busybox_exec_path, argv);
212    bb_perror_msg_and_die("exec %s", bb_busybox_exec_path);
213}
214
215void forkexit_or_rexec(char **argv)
216{
217    pid_t pid;
218    /* Maybe we are already re-execed and come here again? */
219    if (re_execed)
220        return;
221
222    pid = vfork();
223    if (pid < 0) /* wtf? */
224        bb_perror_msg_and_die("vfork");
225    if (pid) /* parent */
226        exit(0);
227    /* child - re-exec ourself */
228    re_exec(argv);
229}
230#else
231/* Dance around (void)...*/
232#undef forkexit_or_rexec
233void forkexit_or_rexec(void)
234{
235    pid_t pid;
236    pid = fork();
237    if (pid < 0) /* wtf? */
238        bb_perror_msg_and_die("fork");
239    if (pid) /* parent */
240        exit(0);
241    /* child */
242}
243#define forkexit_or_rexec(argv) forkexit_or_rexec()
244#endif
245
246/* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
247 * char **argv "vanishes" */
248void bb_daemonize_or_rexec(int flags, char **argv)
249{
250    int fd;
251
252    if (flags & DAEMON_CHDIR_ROOT)
253        xchdir("/");
254
255    if (flags & DAEMON_DEVNULL_STDIO) {
256        close(0);
257        close(1);
258        close(2);
259    }
260
261    fd = xopen(bb_dev_null, O_RDWR);
262
263    while ((unsigned)fd < 2)
264        fd = dup(fd); /* have 0,1,2 open at least to /dev/null */
265
266    if (!(flags & DAEMON_ONLY_SANITIZE)) {
267        forkexit_or_rexec(argv);
268        /* if daemonizing, make sure we detach from stdio & ctty */
269        setsid();
270        dup2(fd, 0);
271        dup2(fd, 1);
272        dup2(fd, 2);
273    }
274    while (fd > 2) {
275        close(fd--);
276        if (!(flags & DAEMON_CLOSE_EXTRA_FDS))
277            return;
278        /* else close everything after fd#2 */
279    }
280}
281
282void bb_sanitize_stdio(void)
283{
284    bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE, NULL);
285}
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