From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Thu, 9 Apr 2020 15:29:18 +0000 (-0400)
Subject: Fix: namespace contexts !CONFIG_RCU_TLS variable initialization
X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=a251a2090be0b47988cd78a448ea818293244ca1;p=lttng-ust.git

Fix: namespace contexts !CONFIG_RCU_TLS variable initialization

The namespace contexts introduced in lttng-ust 2.12 require to
initialize TLS variable to nonzero values. However, in !CONFIG_RCU_TLS
(compatibility mode using pthread setspecific), this initialization
does not build.

Use the new DEFINE_URCU_TLS_INIT from liburcu when building
!CONFIG_RCU_TLS to fix this issue. Since this requires a dependency on
a new liburcu version, only !CONFIG_RCU_TLS adds this dependency in the
fix. A followup cleanup patch will use DEFINE_URCU_TLS_INIT as we add
a strict version dependency.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust/lttng-context-cgroup-ns.c b/liblttng-ust/lttng-context-cgroup-ns.c
index 3526798f..cd9e2bc1 100644
--- a/liblttng-ust/lttng-context-cgroup-ns.c
+++ b/liblttng-ust/lttng-context-cgroup-ns.c
@@ -39,7 +39,11 @@
  * We cache the result to ensure we don't stat(2) the proc filesystem on
  * each event.
  */
+#ifdef CONFIG_RCU_TLS
 static DEFINE_URCU_TLS(ino_t, cached_cgroup_ns) = NS_INO_UNINITIALIZED;
+#else
+static DEFINE_URCU_TLS_INIT(ino_t, cached_cgroup_ns, NS_INO_UNINITIALIZED);
+#endif
 
 static
 ino_t get_cgroup_ns(void)
diff --git a/liblttng-ust/lttng-context-ipc-ns.c b/liblttng-ust/lttng-context-ipc-ns.c
index 64b3cd8e..9890b03b 100644
--- a/liblttng-ust/lttng-context-ipc-ns.c
+++ b/liblttng-ust/lttng-context-ipc-ns.c
@@ -34,12 +34,15 @@
 #include "lttng-tracer-core.h"
 #include "ns.h"
 
-
 /*
  * We cache the result to ensure we don't stat(2) the proc filesystem on
  * each event.
  */
+#ifdef CONFIG_RCU_TLS
 static DEFINE_URCU_TLS(ino_t, cached_ipc_ns) = NS_INO_UNINITIALIZED;
+#else
+static DEFINE_URCU_TLS_INIT(ino_t, cached_ipc_ns, NS_INO_UNINITIALIZED);
+#endif
 
 static
 ino_t get_ipc_ns(void)
diff --git a/liblttng-ust/lttng-context-net-ns.c b/liblttng-ust/lttng-context-net-ns.c
index 3da46d63..c1ae9796 100644
--- a/liblttng-ust/lttng-context-net-ns.c
+++ b/liblttng-ust/lttng-context-net-ns.c
@@ -34,12 +34,15 @@
 #include "lttng-tracer-core.h"
 #include "ns.h"
 
-
 /*
  * We cache the result to ensure we don't stat(2) the proc filesystem on
  * each event.
  */
+#ifdef CONFIG_RCU_TLS
 static DEFINE_URCU_TLS(ino_t, cached_net_ns) = NS_INO_UNINITIALIZED;
+#else
+static DEFINE_URCU_TLS_INIT(ino_t, cached_net_ns, NS_INO_UNINITIALIZED);
+#endif
 
 static
 ino_t get_net_ns(void)
diff --git a/liblttng-ust/lttng-context-uts-ns.c b/liblttng-ust/lttng-context-uts-ns.c
index 43faad0d..77bb21bc 100644
--- a/liblttng-ust/lttng-context-uts-ns.c
+++ b/liblttng-ust/lttng-context-uts-ns.c
@@ -39,7 +39,11 @@
  * We cache the result to ensure we don't stat(2) the proc filesystem on
  * each event.
  */
+#ifdef CONFIG_RCU_TLS
 static DEFINE_URCU_TLS(ino_t, cached_uts_ns) = NS_INO_UNINITIALIZED;
+#else
+static DEFINE_URCU_TLS_INIT(ino_t, cached_uts_ns, NS_INO_UNINITIALIZED);
+#endif
 
 static
 ino_t get_uts_ns(void)