BUG/MINOR: init: fix set-dumpable when using uid/gid

in mworker mode used with uid/gid settings, it was not possible to get
a coredump despite the set-dumpable option.
indeed prctl(2) manual page specifies the dumpable attribute is reverted
to `/proc/sys/fs/suid_dumpable` in a few conditions such as process
effective user and group are changed.

this patch moves the whole set-dumpable logic before the polling code in
order to catch all possible cases where we could have changed the
uid/gid. It however does not cover the possible segfault at startup.

this patch should be backported in 2.0.

Signed-off-by: William Dauchy <w.dauchy@criteo.com>

diff --git a/src/haproxy.c b/src/haproxy.c
index cf23c396fcf241b24375b4ce2eb866add7f343f5..44375f6d348b0e20de025f588463ddb49c5c98d8 100644 (file)
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -3066,49 +3066,6 @@ int main(int argc, char **argv)
                }
        }
 
-       /* try our best to re-enable core dumps depending on system capabilities.
-        * What is addressed here :
-        *   - remove file size limits
-        *   - remove core size limits
-        *   - mark the process dumpable again if it lost it due to user/group
-        */
-       if (global.tune.options & GTUNE_SET_DUMPABLE) {
-               limit.rlim_cur = limit.rlim_max = RLIM_INFINITY;
-
-#if defined(RLIMIT_FSIZE)
-               if (setrlimit(RLIMIT_FSIZE, &limit) == -1) {
-                       if (global.tune.options & GTUNE_STRICT_LIMITS) {
-                               ha_alert("[%s.main()] Failed to set the raise the maximum "
-                                        "file size.\n", argv[0]);
-                               if (!(global.mode & MODE_MWORKER))
-                                       exit(1);
-                       }
-                       else
-                               ha_warning("[%s.main()] Failed to set the raise the maximum "
-                                          "file size. This will fail in >= v2.3\n", argv[0]);
-               }
-#endif
-
-#if defined(RLIMIT_CORE)
-               if (setrlimit(RLIMIT_CORE, &limit) == -1) {
-                       if (global.tune.options & GTUNE_STRICT_LIMITS) {
-                               ha_alert("[%s.main()] Failed to set the raise the core "
-                                        "dump size.\n", argv[0]);
-                               if (!(global.mode & MODE_MWORKER))
-                                       exit(1);
-                       }
-                       else
-                               ha_warning("[%s.main()] Failed to set the raise the core "
-                                          "dump size. This will fail in >= v2.3\n", argv[0]);
-               }
-#endif
-
-#if defined(USE_PRCTL)
-               if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1)
-                       ha_warning("[%s.main()] Failed to set the dumpable flag, no core will be dumped.\n", argv[0]);
-#endif
-       }
-
        /* check ulimits */
        limit.rlim_cur = limit.rlim_max = 0;
        getrlimit(RLIMIT_NOFILE, &limit);
@@ -3403,6 +3360,50 @@ int main(int argc, char **argv)
                fork_poller();
        }
 
+       /* try our best to re-enable core dumps depending on system capabilities.
+        * What is addressed here :
+        *   - remove file size limits
+        *   - remove core size limits
+        *   - mark the process dumpable again if it lost it due to user/group
+        */
+       if (global.tune.options & GTUNE_SET_DUMPABLE) {
+               limit.rlim_cur = limit.rlim_max = RLIM_INFINITY;
+
+#if defined(RLIMIT_FSIZE)
+               if (setrlimit(RLIMIT_FSIZE, &limit) == -1) {
+                       if (global.tune.options & GTUNE_STRICT_LIMITS) {
+                               ha_alert("[%s.main()] Failed to set the raise the maximum "
+                                        "file size.\n", argv[0]);
+                               if (!(global.mode & MODE_MWORKER))
+                                       exit(1);
+                       }
+                       else
+                               ha_warning("[%s.main()] Failed to set the raise the maximum "
+                                          "file size. This will fail in >= v2.3\n", argv[0]);
+               }
+#endif
+
+#if defined(RLIMIT_CORE)
+               if (setrlimit(RLIMIT_CORE, &limit) == -1) {
+                       if (global.tune.options & GTUNE_STRICT_LIMITS) {
+                               ha_alert("[%s.main()] Failed to set the raise the core "
+                                        "dump size.\n", argv[0]);
+                               if (!(global.mode & MODE_MWORKER))
+                                       exit(1);
+                       }
+                       else
+                               ha_warning("[%s.main()] Failed to set the raise the core "
+                                          "dump size. This will fail in >= v2.3\n", argv[0]);
+               }
+#endif
+
+#if defined(USE_PRCTL)
+               if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1)
+                       ha_warning("[%s.main()] Failed to set the dumpable flag, "
+                                  "no core will be dumped.\n", argv[0]);
+#endif
+       }
+
        global.mode &= ~MODE_STARTING;
        /*
         * That's it : the central polling loop. Run until we stop.