libbb: introduce and use safe_waitpid (loops in EINTR)

*: use more approproate (shorter) versions of wait()

function                                             old     new   delta
safe_waitpid                                           -      48     +48
wait_any_nohang                                        -      17     +17
send_tree                                            365     369      +4
processorstop                                        432     435      +3
text_yank                                            110     108      -2
make_human_readable_str                              202     200      -2
crond_main                                          1368    1366      -2
handle_sigchld                                        49      43      -6
reapchild                                            166     159      -7
custom                                               260     250     -10
checkscript                                          191     177     -14
wait_nohang                                           17       -     -17
wait_pid                                              43       -     -43
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 2/7 up/down: 72/-103)           Total: -31 bytes

diff --git a/archival/tar.c b/archival/tar.c
index 5b19093..64975c4 100644 (file)
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -610,7 +610,7 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
 
        if (gzipPid) {
                int status;
-               if (waitpid(gzipPid, &status, 0) == -1)
+               if (safe_waitpid(gzipPid, &status, 0) == -1)
                        bb_perror_msg("waitpid");
                else if (!WIFEXITED(status) || WEXITSTATUS(status))
                        /* gzip was killed or has exited with nonzero! */
@@ -688,7 +688,7 @@ static void handle_SIGCHLD(int status)
        /* Actually, 'status' is a signo. We reuse it for other needs */
 
        /* Wait for any child without blocking */
-       if (waitpid(-1, &status, WNOHANG) < 0)
+       if (wait_any_nohang(&status) < 0)
                /* wait failed?! I'm confused... */
                return;
 

diff --git a/include/libbb.h b/include/libbb.h
index f35f85c..fef8fe2 100644 (file)
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -587,9 +587,9 @@ pid_t xspawn(char **argv);
  *      if (rc < 0) bb_perror_msg("%s", argv[0]);
  *      if (rc > 0) bb_error_msg("exit code: %d", rc);
  */
+int safe_waitpid(int pid, int *wstat, int options);
 int wait4pid(int pid);
-int wait_pid(int *wstat, int pid);
-int wait_nohang(int *wstat);
+int wait_any_nohang(int *wstat);
 #define wait_crashed(w) ((w) & 127)
 #define wait_exitcode(w) ((w) >> 8)
 #define wait_stopsig(w) ((w) >> 8)

diff --git a/init/init.c b/init/init.c
index 51125f3..68a59d8 100644 (file)
--- a/init/init.c
+++ b/init/init.c
@@ -95,9 +95,14 @@ static const char *const environment[] = {
 
 /* Function prototypes */
 static void delete_init_action(struct init_action *a);
-static int waitfor(pid_t pid);
 static void halt_reboot_pwoff(int sig) ATTRIBUTE_NORETURN;
 
+/* TODO: move to libbb? */
+static int waitfor(pid_t runpid)
+{
+       return safe_waitpid(runpid, NULL, 0);
+}
+
 static void loop_forever(void) ATTRIBUTE_NORETURN;
 static void loop_forever(void)
 {
@@ -465,19 +470,6 @@ static pid_t run(const struct init_action *a)
        _exit(-1);
 }
 
-static int waitfor(pid_t runpid)
-{
-       int status, wpid;
-
-       while (1) {
-               wpid = waitpid(runpid, &status, 0);
-               if (wpid == -1 && errno == EINTR)
-                       continue;
-               break;
-       }
-       return wpid;
-}
-
 /* Run all commands of a particular type */
 static void run_actions(int action)
 {
@@ -520,7 +512,7 @@ static void init_reboot(unsigned long magic)
                reboot(magic);
                _exit(0);
        }
-       waitpid(pid, NULL, 0);
+       waitfor(pid);
 }
 
 static void kill_all_processes(void)
@@ -980,7 +972,7 @@ int init_main(int argc, char **argv)
                /* Don't consume all CPU time -- sleep a bit */
                sleep(1);
 
-               /* Wait for a child process to exit */
+               /* Wait for any child process to exit */
                wpid = wait(NULL);
                while (wpid > 0) {
                        /* Find out who died and clean up their corpse */
@@ -995,7 +987,7 @@ int init_main(int argc, char **argv)
                                }
                        }
                        /* see if anyone else is waiting to be reaped */
-                       wpid = waitpid(-1, NULL, WNOHANG);
+                       wpid = wait_any_nohang(NULL);
                }
        }
 }

diff --git a/ipsvd/tcpudp.c b/ipsvd/tcpudp.c
index fc29274..6187eb9 100644 (file)
--- a/ipsvd/tcpudp.c
+++ b/ipsvd/tcpudp.c
@@ -121,7 +121,7 @@ static void sig_child_handler(int sig)
        int wstat;
        int pid;
 
-       while ((pid = wait_nohang(&wstat)) > 0) {
+       while ((pid = wait_any_nohang(&wstat)) > 0) {
                if (max_per_host)
                        ipsvd_perhost_remove(pid);
                if (cnum)

diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index d6e233a..4e6ecde 100644 (file)
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -66,6 +66,21 @@ pid_t xspawn(char **argv)
        return pid;
 }
 
+int safe_waitpid(int pid, int *wstat, int options)
+{
+       int r;
+
+       do
+               r = waitpid(pid, wstat, options);
+       while ((r == -1) && (errno == EINTR));
+       return r;
+}
+
+int wait_any_nohang(int *wstat)
+{
+       return safe_waitpid(-1, wstat, WNOHANG);
+}
+
 // Wait for the specified child PID to exit, returning child's error return.
 int wait4pid(int pid)
 {
@@ -76,28 +91,18 @@ int wait4pid(int pid)
                /* we expect errno to be already set from failed [v]fork/exec */
                return -1;
        }
-       if (waitpid(pid, &status, 0) == -1)
+       if (safe_waitpid(pid, &status, 0) == -1)
                return -1;
        if (WIFEXITED(status))
                return WEXITSTATUS(status);
        if (WIFSIGNALED(status))
                return WTERMSIG(status) + 1000;
        return 0;
-}
-
-int wait_nohang(int *wstat)
-{
-       return waitpid(-1, wstat, WNOHANG);
-}
-
-int wait_pid(int *wstat, int pid)
-{
-       int r;
-
-       do
-               r = waitpid(pid, wstat, 0);
-       while ((r == -1) && (errno == EINTR));
-       return r;
+       if (WIFEXITED(status))
+               return WEXITSTATUS(status);
+       if (WIFSIGNALED(status))
+               return WTERMSIG(status) + 1000;
+       return 0;
 }
 
 #if ENABLE_FEATURE_PREFER_APPLETS

diff --git a/miscutils/crond.c b/miscutils/crond.c
index 8ee7e58..6056cb0 100644 (file)
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -756,7 +756,7 @@ static int CheckJobs(void)
                        for (line = file->cf_LineBase; line; line = line->cl_Next) {
                                if (line->cl_Pid > 0) {
                                        int status;
-                                       int r = wait4(line->cl_Pid, &status, WNOHANG, NULL);
+                                       int r = waitpid(line->cl_Pid, &status, WNOHANG);
 
                                        if (r < 0 || r == line->cl_Pid) {
                                                EndJob(file->cf_User, line);

diff --git a/networking/httpd.c b/networking/httpd.c
index 87dc4b7..7294975 100644 (file)
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -1152,7 +1152,7 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                count = safe_poll(pfd, 3, -1);
                if (count <= 0) {
 #if 0
-                       if (waitpid(pid, &status, WNOHANG) <= 0) {
+                       if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
                                /* Weird. CGI didn't exit and no fd's
                                 * are ready, yet poll returned?! */
                                continue;

diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index 31911cd..68ea01a 100644 (file)
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -944,7 +944,7 @@ static int doit(char *str)
                        execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
                        exit(127);
                }
-               waitpid(child, &status, 0);
+               safe_waitpid(child, &status, 0);
                if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
                        return 0;
                }
@@ -1068,7 +1068,7 @@ static char *run_mapping(char *physical, struct mapping_defn_t * map)
                fprintf(in, "%s\n", map->mapping[i]);
        }
        fclose(in);
-       waitpid(pid, &status, 0);
+       safe_waitpid(pid, &status, 0);
 
        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
                /* If the mapping script exited successfully, try to

diff --git a/networking/inetd.c b/networking/inetd.c
index a9c9397..d643dc6 100644 (file)
--- a/networking/inetd.c
+++ b/networking/inetd.c
@@ -1161,7 +1161,7 @@ static void reapchild(int sig ATTRIBUTE_UNUSED)
        servtab_t *sep;
 
        for (;;) {
-               pid = wait3(&status, WNOHANG, NULL);
+               pid = wait_any_nohang(&status);
                if (pid <= 0)
                        break;
                for (sep = servtab; sep; sep = sep->se_next)

diff --git a/networking/telnetd.c b/networking/telnetd.c
index 108bbf4..0201d26 100644 (file)
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -394,7 +394,7 @@ static void handle_sigchld(int sig)
 
        /* Looping: more than one child may have exited */
        while (1) {
-               pid = waitpid(-1, NULL, WNOHANG);
+               pid = wait_any_nohang(NULL);
                if (pid <= 0)
                        break;
                ts = sessions;

diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
index 8a18898..71f0333 100644 (file)
--- a/networking/udhcp/script.c
+++ b/networking/udhcp/script.c
@@ -232,7 +232,7 @@ void udhcp_run_script(struct dhcpMessage *packet, const char *name)
                       name, NULL, envp);
                bb_perror_msg_and_die("script %s failed", client_config.script);
        }
-       waitpid(pid, NULL, 0);
+       safe_waitpid(pid, NULL, 0);
        for (curr = envp; *curr; curr++)
                free(*curr);
        free(envp);

diff --git a/runit/runsv.c b/runit/runsv.c
index 8c5a4d4..84f5193 100644 (file)
--- a/runit/runsv.c
+++ b/runit/runsv.c
@@ -282,8 +282,7 @@ static unsigned custom(struct svdir *s, char c)
                                execve(a, prog, environ);
                                fatal_cannot("run control/?");
                        }
-                       while (wait_pid(&w, pid) == -1) {
-                               if (errno == EINTR) continue;
+                       while (safe_waitpid(pid, &w, 0) == -1) {
                                warn_cannot("wait for child control/?");
                                return 0;
                        }
@@ -593,7 +592,7 @@ int runsv_main(int argc, char **argv)
                        int child;
                        int wstat;
 
-                       child = wait_nohang(&wstat);
+                       child = wait_any_nohang(&wstat);
                        if (!child)
                                break;
                        if ((child == -1) && (errno != EINTR))

diff --git a/runit/runsvdir.c b/runit/runsvdir.c
index 9e98ca6..8384903 100644 (file)
--- a/runit/runsvdir.c
+++ b/runit/runsvdir.c
@@ -252,7 +252,7 @@ int runsvdir_main(int argc, char **argv)
        for (;;) {
                /* collect children */
                for (;;) {
-                       pid = wait_nohang(&wstat);
+                       pid = wait_any_nohang(&wstat);
                        if (pid <= 0)
                                break;
                        for (i = 0; i < svnum; i++) {

diff --git a/runit/sv.c b/runit/sv.c
index e31adff..a89e244 100644 (file)
--- a/runit/sv.c
+++ b/runit/sv.c
@@ -333,8 +333,7 @@ static int checkscript(void)
                bb_perror_msg(WARN"cannot %s child %s/check", "run", *service);
                return 0;
        }
-       while (wait_pid(&w, pid) == -1) {
-               if (errno == EINTR) continue;
+       while (safe_waitpid(pid, &w, 0) == -1) {
                bb_perror_msg(WARN"cannot %s child %s/check", "wait for", *service);
                return 0;
        }

diff --git a/runit/svlogd.c b/runit/svlogd.c
index 2dc8cb9..1d679c9 100644 (file)
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -265,7 +265,7 @@ static unsigned processorstop(struct logdir *ld)
 
        if (ld->ppid) {
                sig_unblock(SIGHUP);
-               while (wait_pid(&wstat, ld->ppid) == -1)
+               while (safe_waitpid(ld->ppid, &wstat, 0) == -1)
                        pause2cannot("wait for processor", ld->name);
                sig_block(SIGHUP);
                ld->ppid = 0;
@@ -794,7 +794,7 @@ static void sig_child_handler(int sig_no)
 
        if (verbose)
                bb_error_msg(INFO"sig%s received", "child");
-       while ((pid = wait_nohang(&wstat)) > 0) {
+       while ((pid = wait_any_nohang(&wstat)) > 0) {
                for (l = 0; l < dirn; ++l) {
                        if (dir[l].ppid == pid) {
                                dir[l].ppid = 0;

diff --git a/shell/ash.c b/shell/ash.c
index a5b19c8..96563bf 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -3768,7 +3768,7 @@ waitproc(int block, int *status)
 #endif
        if (block == 0)
                flags |= WNOHANG;
-       return wait3(status, flags, (struct rusage *)NULL);
+       return waitpid(-1, status, flags); // safe_waitpid?
 }
 
 /*

diff --git a/shell/hush.c b/shell/hush.c
index cb2c3e9..b08fe10 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1649,6 +1649,7 @@ static int checkjobs(struct pipe* fg_pipe)
 // + killall -STOP cat
 
  wait_more:
+// TODO: safe_waitpid?
        while ((childpid = waitpid(-1, &status, attributes)) > 0) {
                const int dead = WIFEXITED(status) || WIFSIGNALED(status);
 

diff --git a/shell/msh.c b/shell/msh.c
index 9edf793..9e9b798 100644 (file)
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -4162,7 +4162,7 @@ static int grave(int quoted)
                return 0;
        }
        if (i != 0) {
-               waitpid(i, NULL, 0);
+               waitpid(i, NULL, 0); // safe_waitpid?
                global_env.iop->argp->aword = ++cp;
                close(pf[1]);
                PUSHIO(afile, remap(pf[0]),