From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: [RFC][PATCH 4/5] tracepoints: Grab get_online_cpus() before taking tracepoints_mutex
Date: Fri, 12 May 2017 13:15:48 -0400 [thread overview]
Message-ID: <20170512172450.269938638@goodmis.org> (raw)
In-Reply-To: 20170512171544.100715273@goodmis.org
[-- Attachment #1: 0004-tracepoints-Grab-get_online_cpus-before-taking-trace.patch --]
[-- Type: text/plain, Size: 1653 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
There's places that take tracepoints_mutex while holding get_online_cpus(),
and since tracepoints call jump_label code, which also takes
get_online_cpus(), make sure that the tracepoints_mutex is always taken
under get_online_cpus().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/tracepoint.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 685c50ae6300..e41eab51b435 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -23,6 +23,7 @@
#include <linux/rcupdate.h>
#include <linux/tracepoint.h>
#include <linux/err.h>
+#include <linux/cpu.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
@@ -276,12 +277,14 @@ int tracepoint_probe_register_prio(struct tracepoint *tp, void *probe,
struct tracepoint_func tp_func;
int ret;
+ get_online_cpus();
mutex_lock(&tracepoints_mutex);
tp_func.func = probe;
tp_func.data = data;
tp_func.prio = prio;
ret = tracepoint_add_func(tp, &tp_func, prio);
mutex_unlock(&tracepoints_mutex);
+ put_online_cpus();
return ret;
}
EXPORT_SYMBOL_GPL(tracepoint_probe_register_prio);
@@ -318,11 +321,13 @@ int tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data)
struct tracepoint_func tp_func;
int ret;
+ get_online_cpus();
mutex_lock(&tracepoints_mutex);
tp_func.func = probe;
tp_func.data = data;
ret = tracepoint_remove_func(tp, &tp_func);
mutex_unlock(&tracepoints_mutex);
+ put_online_cpus();
return ret;
}
EXPORT_SYMBOL_GPL(tracepoint_probe_unregister);
--
2.10.2
next prev parent reply other threads:[~2017-05-12 17:26 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-12 17:15 [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Steven Rostedt
2017-05-12 17:15 ` [RFC][PATCH 1/5] tracing: Make sure RCU is watching before calling a stack trace Steven Rostedt
2017-05-12 18:25 ` Paul E. McKenney
2017-05-12 18:36 ` Steven Rostedt
2017-05-12 18:50 ` Paul E. McKenney
2017-05-12 20:05 ` Steven Rostedt
2017-05-12 20:31 ` Paul E. McKenney
2017-05-17 16:46 ` Steven Rostedt
2017-05-12 17:15 ` [RFC][PATCH 2/5] cpu-hotplug: Allow get_online_cpus() to nest Steven Rostedt
2017-05-12 18:35 ` Paul E. McKenney
2017-05-12 18:40 ` Steven Rostedt
2017-05-12 18:52 ` Paul E. McKenney
2017-05-12 22:15 ` Thomas Gleixner
2017-05-13 0:23 ` Steven Rostedt
2017-05-12 17:15 ` [RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() Steven Rostedt
2017-05-12 18:39 ` Paul E. McKenney
2017-05-12 18:44 ` Steven Rostedt
2017-05-17 17:50 ` Masami Hiramatsu
2017-05-12 17:15 ` Steven Rostedt [this message]
2017-05-12 17:15 ` [RFC][PATCH 5/5] perf: Grab event_mutex before taking get_online_cpus() Steven Rostedt
2017-05-12 18:13 ` [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Paul E. McKenney
2017-05-12 19:49 ` Peter Zijlstra
2017-05-12 20:14 ` Steven Rostedt
2017-05-12 21:34 ` Steven Rostedt
2017-05-13 13:40 ` Paul E. McKenney
2017-05-15 9:03 ` Peter Zijlstra
2017-05-15 18:40 ` Paul E. McKenney
2017-05-16 8:19 ` Peter Zijlstra
2017-05-16 12:46 ` Paul E. McKenney
2017-05-16 14:27 ` Paul E. McKenney
2017-05-17 10:40 ` Peter Zijlstra
2017-05-17 14:55 ` Paul E. McKenney
2017-05-18 3:58 ` Paul E. McKenney
2017-05-15 19:06 ` Steven Rostedt
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