acpid: close fds which are reported as dead (POLLERR/POLLHUP/POLLNVAL) by poll.

function                                             old     new   delta
acpid_main                                          1159    1229     +70
packed_usage                                       28977   28980      +3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 35 insertions, 19 deletions

diff --git a/util-linux/acpid.c b/util-linux/acpid.c
index 6e7321b02..361a2b206 100644
--- a/util-linux/acpid.c
+++ b/util-linux/acpid.c
@@ -8,13 +8,13 @@
  */
 
 //usage:#define acpid_trivial_usage
-//usage:       "[-d] [-c CONFDIR] [-l LOGFILE] [-a ACTIONFILE] [-M MAPFILE] [-e PROC_EVENT_FILE] [-p PIDFILE]"
+//usage:       "[-df] [-c CONFDIR] [-l LOGFILE] [-a ACTIONFILE] [-M MAPFILE] [-e PROC_EVENT_FILE] [-p PIDFILE]"
 //usage:#define acpid_full_usage "\n\n"
 //usage:       "Listen to ACPI events and spawn specific helpers on event arrival\n"
+//usage:     "\n        -d      Log to stderr, not log file (implies -f)"
+//usage:     "\n        -f      Run in foreground"
 //usage:     "\n        -c DIR  Config directory [/etc/acpi]"
-//usage:     "\n        -d      Don't daemonize, (implies -f)"
 //usage:     "\n        -e FILE /proc event file [/proc/acpi/event]"
-//usage:     "\n        -f      Run in foreground"
 //usage:     "\n        -l FILE Log file [/var/log/acpid.log]"
 //usage:     "\n        -p FILE Pid file [/var/run/acpid.pid]"
 //usage:     "\n        -a FILE Action file [/etc/acpid.conf]"
@@ -225,7 +225,6 @@ static void parse_map_file(const char *filename)
 int acpid_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int acpid_main(int argc UNUSED_PARAM, char **argv)
 {
-        struct input_event ev;
         int nfd;
         int opts;
         struct pollfd *pfd;
@@ -248,15 +247,21 @@ int acpid_main(int argc UNUSED_PARAM, char **argv)
         );
 
         if (!(opts & OPT_f)) {
+                /* No -f "Foreground", we go to background */
                 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
         }
 
         if (!(opts & OPT_d)) {
+                /* No -d "Debug", we log to log file.
+                 * This includes any output from children.
+                 */
+                xmove_fd(xopen(opt_logfile, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
+                xdup2(STDOUT_FILENO, STDERR_FILENO);
+                /* Also, acpid's messages (but not children) will go to syslog too */
                 openlog(applet_name, LOG_PID, LOG_DAEMON);
                 logmode = LOGMODE_SYSLOG | LOGMODE_STDIO;
-        } else {
-                xmove_fd(xopen(opt_logfile, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
         }
+        /* else: -d "Debug", log is not redirected */
 
         parse_conf_file(opt_action);
         parse_map_file(opt_map);
@@ -272,13 +277,14 @@ int acpid_main(int argc UNUSED_PARAM, char **argv)
                 int fd;
                 char *dev_event;
 
-                dev_event = xasprintf((option_mask32 & OPT_e) ? "%s" : "%s%u", opt_input, nfd);
+                dev_event = xasprintf((opts & OPT_e) ? "%s" : "%s%u", opt_input, nfd);
                 fd = open(dev_event, O_RDONLY | O_NONBLOCK);
                 if (fd < 0) {
                         if (nfd == 0)
                                 bb_simple_perror_msg_and_die(dev_event);
                         break;
                 }
+                free(dev_event);
                 pfd = xrealloc_vector(pfd, 1, nfd);
                 pfd[nfd].fd = fd;
                 pfd[nfd].events = POLLIN;
@@ -287,16 +293,26 @@ int acpid_main(int argc UNUSED_PARAM, char **argv)
 
         write_pidfile(opt_pidfile);
 
-        while (poll(pfd, nfd, -1) > 0) {
+        while (safe_poll(pfd, nfd, -1) > 0) {
                 int i;
                 for (i = 0; i < nfd; i++) {
-                        const char *event = NULL;
-
-                        memset(&ev, 0, sizeof(ev));
-
-                        if (!(pfd[i].revents & POLLIN))
-                                continue;
+                        const char *event;
+
+                        if (!(pfd[i].revents & POLLIN)) {
+                                if (pfd[i].revents == 0)
+                                        continue; /* this fd has nothing */
+
+                                /* Likely POLLERR, POLLHUP, POLLNVAL.
+                                 * Do not listen on this fd anymore.
+                                 */
+                                close(pfd[i].fd);
+                                nfd--;
+                                for (; i < nfd; i++)
+                                        pfd[i].fd = pfd[i + 1].fd;
+                                break; /* do poll() again */
+                        }
 
+                        event = NULL;
                         if (option_mask32 & OPT_e) {
                                 char *buf;
                                 int len;
@@ -307,7 +323,10 @@ int acpid_main(int argc UNUSED_PARAM, char **argv)
                                 if (len >= 0)
                                         buf[len] = '\0';
                                 event = find_action(NULL, buf);
+                                free(buf);
                         } else {
+                                struct input_event ev;
+
                                 if (sizeof(ev) != full_read(pfd[i].fd, &ev, sizeof(ev)))
                                         continue;
 
@@ -324,11 +343,8 @@ int acpid_main(int argc UNUSED_PARAM, char **argv)
         }
 
         if (ENABLE_FEATURE_CLEAN_UP) {
-                while (nfd--) {
-                        if (pfd[nfd].fd) {
-                                close(pfd[nfd].fd);
-                        }
-                }
+                while (nfd--)
+                        close(pfd[nfd].fd);
                 free(pfd);
         }
         remove_pidfile(opt_pidfile);