From af178143343028fdec9d5960a22d17f5587fd3f5 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt@goodmis.org>
Date: Mon, 9 Sep 2024 10:32:31 -0400
Subject: [PATCH 1/2] tracing/osnoise: Fix build when timerlat is not enabled

To fix some critical section races, the interface_lock was added to a few
locations. One of those locations was above where the interface_lock was
declared, so the declaration was moved up before that usage.
Unfortunately, where it was placed was inside a CONFIG_TIMERLAT_TRACER
ifdef block. As the interface_lock is used outside that config, this broke
the build when CONFIG_OSNOISE_TRACER was enabled but
CONFIG_TIMERLAT_TRACER was not.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Helena Anna" <helena.anna.dubel@intel.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Link: https://lore.kernel.org/20240909103231.23a289e2@gandalf.local.home
Fixes: e6a53481da29 ("tracing/timerlat: Only clear timer if a kthread exists")
Reported-by: "Bityutskiy, Artem" <artem.bityutskiy@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_osnoise.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index bbe47781617e..7e75c1214b36 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -228,6 +228,11 @@ static inline struct osnoise_variables *this_cpu_osn_var(void)
 	return this_cpu_ptr(&per_cpu_osnoise_var);
 }
 
+/*
+ * Protect the interface.
+ */
+static struct mutex interface_lock;
+
 #ifdef CONFIG_TIMERLAT_TRACER
 /*
  * Runtime information for the timer mode.
@@ -252,11 +257,6 @@ static inline struct timerlat_variables *this_cpu_tmr_var(void)
 	return this_cpu_ptr(&per_cpu_timerlat_var);
 }
 
-/*
- * Protect the interface.
- */
-static struct mutex interface_lock;
-
 /*
  * tlat_var_reset - Reset the values of the given timerlat_variables
  */

From 4e378158e5c15bd237a6ff44b7abb9184d61208c Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Mon, 9 Sep 2024 13:53:14 +0300
Subject: [PATCH 2/2] tracing: Drop unused helper function to fix the build

A helper function defined but not used. This, in particular,
prevents kernel builds with clang, `make W=1` and CONFIG_WERROR=y:

kernel/trace/trace.c:2229:19: error: unused function 'run_tracer_selftest' [-Werror,-Wunused-function]
 2229 | static inline int run_tracer_selftest(struct tracer *type)
      |                   ^~~~~~~~~~~~~~~~~~~

Fix this by dropping unused functions.

See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
inline functions for W=1 build").

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/20240909105314.928302-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index edf6bc817aa1..c3b2c7dfadef 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2226,10 +2226,6 @@ static __init int init_trace_selftests(void)
 }
 core_initcall(init_trace_selftests);
 #else
-static inline int run_tracer_selftest(struct tracer *type)
-{
-	return 0;
-}
 static inline int do_run_tracer_selftest(struct tracer *type)
 {
 	return 0;