Fix: lttng_statedump_process_state for each PID NS has infinite loop

[lttng-modules.git] / lttng-statedump-impl.c

diff --git a/lttng-statedump-impl.c b/lttng-statedump-impl.c
index c510986f504b0cedd1c857fec8d99c4d01978e22..c92c331bee0a20be37ad5a985bc9ff970f9b75c0 100644 (file)
--- a/lttng-statedump-impl.c
+++ b/lttng-statedump-impl.c
@@ -186,6 +186,12 @@ int lttng_enumerate_file_descriptors(struct lttng_session *session)
        return 0;
 }
 
+#if 0
+/*
+ * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
+ * (scheduling in atomic). Normally, the tasklist lock protects this kind of
+ * iteration, but it is not exported to modules.
+ */
 static
 void lttng_enumerate_task_vm_maps(struct lttng_session *session,
                struct task_struct *p)
@@ -226,6 +232,7 @@ int lttng_enumerate_vm_maps(struct lttng_session *session)
        rcu_read_unlock();
        return 0;
 }
+#endif
 
 #ifdef CONFIG_GENERIC_HARDIRQS
 
@@ -265,6 +272,33 @@ void list_interrupts(struct lttng_session *session)
 }
 #endif
 
+static
+void lttng_statedump_process_ns(struct lttng_session *session,
+               struct task_struct *p,
+               enum lttng_thread_type type,
+               enum lttng_execution_mode mode,
+               enum lttng_execution_submode submode,
+               enum lttng_process_status status)
+{
+       struct nsproxy *proxy;
+       struct pid_namespace *pid_ns;
+
+       rcu_read_lock();
+       proxy = task_nsproxy(p);
+       if (proxy) {
+               pid_ns = proxy->pid_ns;
+               do {
+                       trace_lttng_statedump_process_state(session,
+                               p, type, mode, submode, status, pid_ns);
+                       pid_ns = pid_ns->parent;
+               } while (pid_ns);
+       } else {
+               trace_lttng_statedump_process_state(session,
+                       p, type, mode, submode, status, NULL);
+       }
+       rcu_read_unlock();
+}
+
 static
 int lttng_enumerate_process_states(struct lttng_session *session)
 {
@@ -314,7 +348,7 @@ int lttng_enumerate_process_states(struct lttng_session *session)
                                type = LTTNG_USER_THREAD;
                        else
                                type = LTTNG_KERNEL_THREAD;
-                       trace_lttng_statedump_process_state(session,
+                       lttng_statedump_process_ns(session,
                                p, type, mode, submode, status);
                        task_unlock(p);
                } while_each_thread(g, p);
@@ -341,7 +375,7 @@ int do_lttng_statedump(struct lttng_session *session)
        trace_lttng_statedump_start(session);
        lttng_enumerate_process_states(session);
        lttng_enumerate_file_descriptors(session);
-       lttng_enumerate_vm_maps(session);
+       /* FIXME lttng_enumerate_vm_maps(session); */
        lttng_list_interrupts(session);
        lttng_enumerate_network_ip_interface(session);