From 369bc18f9a6c4e2686204c1d7476ab684a720968 Mon Sep 17 00:00:00 2001
From: Stefan Assmann <sassmann@redhat.com>
Date: Mon, 12 Oct 2009 22:17:21 +0200
Subject: ftrace: add kernel command line graph function filtering
Add a command line parameter to allow limiting the function graphs
that are traced on boot up from the given top-level callers , when
ftrace=function_graph is specified.
This patch adds the following command line option:
ftrace_graph_filter=function-list
Where function-list is a comma separated list of functions to filter.
[fweisbec@gmail.com: picked the documentation changes from the v2 patch]
Signed-off-by: Stefan Assmann <sassmann@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4AD2DEB9.2@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
kernel/trace/ftrace.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
(limited to 'kernel/trace')
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9a72853a8f0..91283d40821 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -78,6 +78,10 @@ ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
+#endif
+
static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
{
struct ftrace_ops *op = ftrace_list;
@@ -2248,6 +2252,7 @@ void ftrace_set_notrace(unsigned char *buf, int len, int reset)
#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
static int __init set_ftrace_notrace(char *str)
{
@@ -2263,6 +2268,31 @@ static int __init set_ftrace_filter(char *str)
}
__setup("ftrace_filter=", set_ftrace_filter);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int __init set_graph_function(char *str)
+{
+ strncpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_graph_filter=", set_graph_function);
+
+static void __init set_ftrace_early_graph(char *buf)
+{
+ int ret;
+ char *func;
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ /* we allow only one expression at a time */
+ ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
+ func);
+ if (ret)
+ printk(KERN_DEBUG "ftrace: function %s not "
+ "traceable\n", func);
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
static void __init set_ftrace_early_filter(char *buf, int enable)
{
char *func;
@@ -2279,6 +2309,10 @@ static void __init set_ftrace_early_filters(void)
set_ftrace_early_filter(ftrace_filter_buf, 1);
if (ftrace_notrace_buf[0])
set_ftrace_early_filter(ftrace_notrace_buf, 0);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (ftrace_graph_buf[0])
+ set_ftrace_early_graph(ftrace_graph_buf);
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
}
static int
--
cgit
From aef6f81b55f462082699c06e8e67e6eb5630ed45 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Mon, 12 Oct 2009 22:23:24 +0200
Subject: tracing: Rename set_ftrace to set_bootup_ftrace
Do this rename because set_ftrace is too much generic and not enough
self-explainable as a name.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
---
kernel/trace/trace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 45068269ebb..866daf8497f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -129,7 +129,7 @@ static int tracing_set_tracer(const char *buf);
static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
static char *default_bootup_tracer;
-static int __init set_ftrace(char *str)
+static int __init set_bootup_ftrace(char *str)
{
strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
default_bootup_tracer = bootup_tracer_buf;
@@ -137,7 +137,7 @@ static int __init set_ftrace(char *str)
ring_buffer_expanded = 1;
return 1;
}
-__setup("ftrace=", set_ftrace);
+__setup("ftrace=", set_bootup_ftrace);
static int __init set_ftrace_dump_on_oops(char *str)
{
--
cgit
From bf7c5b43a12614847b83f507fb169ad30640e406 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Mon, 12 Oct 2009 22:31:32 +0200
Subject: tracing: Remove unused ftrace_trace_addr helper
Remove the ftrace_trace_addr() function as only its off-case is
implemented and there are no users of it currently.
But we keep ftrace_graph_addr() off-case, in case someone come to use
the function graph tracer to profit from top-level callers filtering.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
---
kernel/trace/trace.h | 4 ----
1 file changed, 4 deletions(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 365fb19d9e1..f22a7ac3238 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -483,10 +483,6 @@ static inline int ftrace_graph_addr(unsigned long addr)
return 0;
}
#else
-static inline int ftrace_trace_addr(unsigned long addr)
-{
- return 1;
-}
static inline int ftrace_graph_addr(unsigned long addr)
{
return 1;
--
cgit