From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: [PATCH 04/12 -next] ftrace: Fix global function tracers that are not recursion safe
Date: Wed, 23 Jan 2013 15:30:06 -0500 [thread overview]
Message-ID: <20130123203433.845671704@goodmis.org> (raw)
In-Reply-To: 20130123203002.957226869@goodmis.org
[-- Attachment #1: 0004-ftrace-Fix-global-function-tracers-that-are-not-recu.patch --]
[-- Type: text/plain, Size: 1434 bytes --]
From: Steven Rostedt <srostedt@redhat.com>
If one of the function tracers set by the global ops is not recursion
safe, it can still be called directly without the added recursion
supplied by the ftrace infrastructure.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 6e34dc1..789cbec 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -221,10 +221,24 @@ static void update_global_ops(void)
* registered callers.
*/
if (ftrace_global_list == &ftrace_list_end ||
- ftrace_global_list->next == &ftrace_list_end)
+ ftrace_global_list->next == &ftrace_list_end) {
func = ftrace_global_list->func;
- else
+ /*
+ * As we are calling the function directly.
+ * If it does not have recursion protection,
+ * the function_trace_op needs to be updated
+ * accordingly.
+ */
+ if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
+ global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
+ else
+ global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
+ } else {
func = ftrace_global_list_func;
+ /* The list has its own recursion protection. */
+ global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
+ }
+
/* If we filter on pids, update to use the pid function */
if (!list_empty(&ftrace_pids)) {
--
1.7.10.4
next prev parent reply other threads:[~2013-01-23 20:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-23 20:30 [PATCH 00/12 -next] [for linux-next] ftrace: Recursion protection and speed up Steven Rostedt
2013-01-23 20:30 ` [PATCH 01/12 -next] tracing: Remove trace.h header from trace_clock.c Steven Rostedt
2013-01-23 20:30 ` [PATCH 02/12 -next] tracing: Fix race with max_tr and changing tracers Steven Rostedt
2013-01-23 20:30 ` [PATCH 03/12 -next] tracing: Fix selftest function recursion accounting Steven Rostedt
2013-01-23 20:30 ` Steven Rostedt [this message]
2013-01-23 20:30 ` [PATCH 05/12 -next] ftrace: Fix function tracing recursion self test Steven Rostedt
2013-01-23 20:30 ` [PATCH 06/12 -next] ftrace: Optimize the function tracer list loop Steven Rostedt
2013-01-23 20:30 ` [PATCH 07/12 -next] ftrace: Add context level recursion bit checking Steven Rostedt
2013-01-23 20:30 ` [PATCH 08/12 -next] tracing: Make the trace recursion bits into enums Steven Rostedt
2013-01-23 20:30 ` [PATCH 09/12 -next] tracing: Avoid unnecessary multiple recursion checks Steven Rostedt
2013-01-23 20:30 ` [PATCH 10/12 -next] ftrace: Use only the preempt version of function tracing Steven Rostedt
2013-01-23 20:30 ` [PATCH 11/12 -next] ring-buffer: User context bit recursion checking Steven Rostedt
2013-01-23 20:30 ` [PATCH 12/12 -next] ring-buffer: Remove trace.h from ring_buffer.c Steven Rostedt
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