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factor out NOFORK/NOEXEC code from find. Use it for xargs too.

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This commit is contained in:
Denis Vlasenko
2007-04-09 21:32:30 +00:00
parent 1b4b2cb20e
commit cd7001f705
4 changed files with 76 additions and 68 deletions
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30
findutils/find.c
View File

@@ -243,32 +243,14 @@ ACTF(exec)
argv[i] = subst(ap->exec_argv[i], ap->subst_count[i], fileName);
argv[i] = NULL; /* terminate the list */
if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
const struct BB_applet *a = find_applet_by_name(argv[0]);
if (a) {
if (a->nofork) {
rc = a->main(ap->exec_argc, argv);
goto f;
}
#ifndef BB_NOMMU
if (a->noexec) {
rc = fork();
if (rc) goto w;
current_applet = a;
run_current_applet_and_exit(ap->exec_argc, argv);
}
#endif
}
}
rc = spawn(argv);
w:
rc = wait4pid(rc);
rc = spawn_and_wait(argv);
if (rc < 0)
bb_perror_msg("%s", argv[0]);
f:
for (i = 0; i < ap->exec_argc; i++)
free(argv[i]);
return rc == 0; /* return 1 if success */
i = 0;
while (argv[i])
free(argv[i++]);
return rc == 0; /* return 1 if exitcode 0 */
}
#endif

35
findutils/xargs.c
View File

@@ -48,47 +48,32 @@
This function has special algorithm.
Don't use fork and include to main!
*/
static int xargs_exec(char *const *args)
static int xargs_exec(char **args)
{
pid_t p;
volatile int exec_errno = 0; /* shared vfork stack */
int status;
p = vfork();
if (p < 0)
bb_perror_msg_and_die("vfork");
if (p == 0) {
/* vfork -- child */
BB_EXECVP(args[0], args);
exec_errno = errno; /* set error to shared stack */
_exit(1);
}
/* vfork -- parent */
while (wait(&status) == (pid_t) -1)
if (errno != EINTR)
break;
if (exec_errno) {
errno = exec_errno;
status = spawn_and_wait(args);
if (status < 0) {
bb_perror_msg("%s", args[0]);
return exec_errno == ENOENT ? 127 : 126;
return errno == ENOENT ? 127 : 126;
}
if (WEXITSTATUS(status) == 255) {
if (status == 255) {
bb_error_msg("%s: exited with status 255; aborting", args[0]);
return 124;
}
/* Huh? I think we won't see this, ever. We don't wait with WUNTRACED!
if (WIFSTOPPED(status)) {
bb_error_msg("%s: stopped by signal %d",
args[0], WSTOPSIG(status));
return 125;
}
if (WIFSIGNALED(status)) {
*/
if (status >= 1000) {
bb_error_msg("%s: terminated by signal %d",
args[0], WTERMSIG(status));
args[0], status - 1000);
return 125;
}
if (WEXITSTATUS(status))
if (status)
return 123;
return 0;
}

35
include/libbb.h
View File

@@ -269,17 +269,6 @@ char *xrealloc_getcwd_or_warn(char *cwd);
char *xmalloc_readlink_or_warn(const char *path);
char *xmalloc_realpath(const char *path);
/* Unlike waitpid, waits ONLY for one process,
* It's safe to pass negative 'pids' from failed [v]fork -
* wait4pid will return -1 and ECHILD in errno.
* IOW: rc = wait4pid(spawn(argv));
* if (rc < 0) bb_perror_msg("%s", argv[0]);
* if (rc > 0) bb_error_msg("exit code: %d", rc);
*/
extern int wait4pid(int pid);
extern int wait_pid(int *wstat, int pid);
extern int wait_nohang(int *wstat);
//TODO: signal(sid, f) is the same? then why?
extern void sig_catch(int,void (*)(int));
//#define sig_ignore(s) (sig_catch((s), SIG_IGN))
//#define sig_uncatch(s) (sig_catch((s), SIG_DFL))
@@ -288,10 +277,6 @@ extern void sig_unblock(int);
/* UNUSED: extern void sig_blocknone(void); */
extern void sig_pause(void);
#define wait_crashed(w) ((w) & 127)
#define wait_exitcode(w) ((w) >> 8)
#define wait_stopsig(w) ((w) >> 8)
#define wait_stopped(w) (((w) & 127) == 127)
void xsetgid(gid_t gid);
@@ -528,6 +513,25 @@ int bb_execvp(const char *file, char *const argv[]);
/* NOMMU friendy fork+exec */
pid_t spawn(char **argv);
pid_t xspawn(char **argv);
/* Unlike waitpid, waits ONLY for one process,
* It's safe to pass negative 'pids' from failed [v]fork -
* wait4pid will return -1 and ECHILD in errno.
* IOW: rc = wait4pid(spawn(argv));
* if (rc < 0) bb_perror_msg("%s", argv[0]);
* if (rc > 0) bb_error_msg("exit code: %d", rc);
*/
int wait_pid(int *wstat, int pid);
int wait_nohang(int *wstat);
int wait4pid(int pid);
//TODO: signal(sid, f) is the same? then why?
#define wait_crashed(w) ((w) & 127)
#define wait_exitcode(w) ((w) >> 8)
#define wait_stopsig(w) ((w) >> 8)
#define wait_stopped(w) (((w) & 127) == 127)
/* wait4pid(spawn(argv)) + NOFORK/NOEXEC (if configured) */
int spawn_and_wait(char **argv);
/* Helpers for daemonization.
*
* bb_daemonize(flags) = daemonize, does not compile on NOMMU
@@ -573,6 +577,7 @@ void bb_daemonize_or_rexec(int flags, char **argv);
void bb_sanitize_stdio(void);
// TODO: always error out?
enum { BB_GETOPT_ERROR = 0x80000000 };
extern const char *opt_complementary;
#if ENABLE_GETOPT_LONG

42
libbb/vfork_daemon_rexec.c
View File

@@ -16,7 +16,7 @@
*/
#include <paths.h>
#include "libbb.h"
#include "busybox.h" /* for struct BB_applet */
/* This does a fork/exec in one call, using vfork(). Returns PID of new child,
* -1 for failure. Runs argv[0], searching path if that has no / in it. */
@@ -72,7 +72,8 @@ int wait4pid(int pid)
int status;
if (pid <= 0) {
/*errno = ECHILD; -- wrong. we expect errno to be set from failed exec */
/*errno = ECHILD; -- wrong. */
/* we expect errno to be already set from failed [v]fork/exec */
return -1;
}
if (waitpid(pid, &status, 0) == -1)
@@ -80,7 +81,7 @@ int wait4pid(int pid)
if (WIFEXITED(status))
return WEXITSTATUS(status);
if (WIFSIGNALED(status))
return WTERMSIG(status) + 10000;
return WTERMSIG(status) + 1000;
return 0;
}
@@ -99,6 +100,41 @@ int wait_pid(int *wstat, int pid)
return r;
}
int spawn_and_wait(char **argv)
{
int rc;
if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
const struct BB_applet *a = find_applet_by_name(argv[0]);
if (a && (a->nofork
#ifndef BB_NOMMU
|| a->noexec /* NOEXEC cannot be used on NOMMU */
#endif
)) {
int argc = 1;
char **pp = argv;
while (*++pp)
argc++;
#ifdef BB_NOMMU
return a->main(argc, argv);
#else
if (a->nofork)
return a->main(argc, argv);
/* a->noexec is true */
rc = fork();
if (rc)
goto w;
/* child */
current_applet = a;
run_current_applet_and_exit(argc, argv);
#endif
}
}
rc = spawn(argv);
w:
return wait4pid(rc);
}
#if 0 //ndef BB_NOMMU
// Die with an error message if we can't daemonize.
void xdaemon(int nochdir, int noclose)