Fix: compat poll: add missing empty revents checks

[lttng-tools.git] / src / bin / lttng-relayd / health-relayd.c

diff --git a/src/bin/lttng-relayd/health-relayd.c b/src/bin/lttng-relayd/health-relayd.c
index 2ce1c1fdafa763a180e15d894de041fb55369664..75149ba4b46526a0494bfea623b3115c676064d4 100644 (file)
--- a/src/bin/lttng-relayd/health-relayd.c
+++ b/src/bin/lttng-relayd/health-relayd.c
@@ -16,6 +16,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <fcntl.h>
 #include <getopt.h>
 #include <grp.h>
@@ -53,9 +54,8 @@
 #include "health-relayd.h"
 
 /* Global health check unix path */
-static char health_unix_sock_path[PATH_MAX];
-static char *relayd_path;
-static char *lttng_rundir;
+static
+char health_unix_sock_path[PATH_MAX];
 
 int health_quit_pipe[2];
 
@@ -131,16 +131,40 @@ error:
        return ret;
 }
 
+static
+int parse_health_env(void)
+{
+       const char *health_path;
+
+       health_path = getenv(LTTNG_RELAYD_HEALTH_ENV);
+       if (health_path) {
+               strncpy(health_unix_sock_path, health_path,
+                       PATH_MAX);
+               health_unix_sock_path[PATH_MAX - 1] = '\0';
+       }
+
+       return 0;
+}
+
 static
 int setup_health_path(void)
 {
        int is_root, ret = 0;
-       char *home_path = NULL;
+       char *home_path = NULL, *rundir = NULL, *relayd_path;
+
+       ret = parse_health_env();
+       if (ret) {
+               return ret;
+       }
 
        is_root = !getuid();
 
        if (is_root) {
-               lttng_rundir = strdup(DEFAULT_LTTNG_RUNDIR);
+               rundir = strdup(DEFAULT_LTTNG_RUNDIR);
+               if (!rundir) {
+                       ret = -ENOMEM;
+                       goto end;
+               }
        } else {
                /*
                 * Create rundir from home path. This will create something like
@@ -155,20 +179,20 @@ int setup_health_path(void)
                        goto end;
                }
 
-               ret = asprintf(&lttng_rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
+               ret = asprintf(&rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
                if (ret < 0) {
                        ret = -ENOMEM;
                        goto end;
                }
        }
 
-       ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, lttng_rundir);
+       ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, rundir);
        if (ret < 0) {
                ret = -ENOMEM;
                goto end;
        }
 
-       ret = create_lttng_rundir_with_perm(lttng_rundir);
+       ret = create_lttng_rundir_with_perm(rundir);
        if (ret < 0) {
                goto end;
        }
@@ -197,6 +221,7 @@ int setup_health_path(void)
        }
 
 end:
+       free(rundir);
        return ret;
 }
 
@@ -280,6 +305,8 @@ void *thread_manage_health(void *data)
                goto error;
        }
 
+       lttng_relay_notify_ready();
+
        while (1) {
                DBG("Health check ready");
 
@@ -303,6 +330,11 @@ restart:
                        revents = LTTNG_POLL_GETEV(&events, i);
                        pollfd = LTTNG_POLL_GETFD(&events, i);
 
+                       if (!revents) {
+                               /* No activity for this FD (poll implementation). */
+                               continue;
+                       }
+
                        /* Thread quit pipe has been closed. Killing thread. */
                        ret = check_health_quit_pipe(pollfd, revents);
                        if (ret) {
@@ -346,7 +378,7 @@ restart:
 
                assert(msg.cmd == HEALTH_CMD_CHECK);
 
-               reply.ret_code = 0;
+               memset(&reply, 0, sizeof(reply));
                for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
                        /*
                         * health_check_state return 0 if thread is in
@@ -379,11 +411,6 @@ error:
        }
        DBG("Health check thread dying");
        unlink(health_unix_sock_path);
-       (void) rmdir(relayd_path);
-       free(relayd_path);
-       (void) rmdir(lttng_rundir);
-       free(lttng_rundir);
-
        if (sock >= 0) {
                ret = close(sock);
                if (ret) {
@@ -391,6 +418,11 @@ error:
                }
        }
 
+       /*
+        * We do NOT rmdir rundir nor the relayd path because there are
+        * other processes using them.
+        */
+
        lttng_poll_clean(&events);
 
        rcu_unregister_thread();