trace: clean up format errors in calls to trace_seq_printf
[linux-2.6-block.git] / kernel / trace / trace_functions.c
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1/*
2 * ring buffer based function tracer
3 *
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
6 *
7 * Based on code from the latency_tracer, that is:
8 *
9 * Copyright (C) 2004-2006 Ingo Molnar
10 * Copyright (C) 2004 William Lee Irwin III
11 */
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12#include <linux/debugfs.h>
13#include <linux/uaccess.h>
14#include <linux/ftrace.h>
2e0f5761 15#include <linux/fs.h>
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16
17#include "trace.h"
18
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19static struct trace_array *func_trace;
20
e309b41d 21static void start_function_trace(struct trace_array *tr)
1b29b018 22{
bb3c3c95 23 func_trace = tr;
26bc83f4 24 tr->cpu = get_cpu();
213cc060 25 tracing_reset_online_cpus(tr);
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26 put_cpu();
27
41bc8144 28 tracing_start_cmdline_record();
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29 tracing_start_function_trace();
30}
31
e309b41d 32static void stop_function_trace(struct trace_array *tr)
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33{
34 tracing_stop_function_trace();
41bc8144 35 tracing_stop_cmdline_record();
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36}
37
1c80025a 38static int function_trace_init(struct trace_array *tr)
1b29b018 39{
c76f0694 40 start_function_trace(tr);
1c80025a 41 return 0;
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42}
43
e309b41d 44static void function_trace_reset(struct trace_array *tr)
1b29b018 45{
c76f0694 46 stop_function_trace(tr);
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47}
48
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49static void function_trace_start(struct trace_array *tr)
50{
213cc060 51 tracing_reset_online_cpus(tr);
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52}
53
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54static void
55function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
56{
57 struct trace_array *tr = func_trace;
58 struct trace_array_cpu *data;
59 unsigned long flags;
60 long disabled;
61 int cpu, resched;
62 int pc;
63
64 if (unlikely(!ftrace_function_enabled))
65 return;
66
67 pc = preempt_count();
68 resched = ftrace_preempt_disable();
69 local_save_flags(flags);
70 cpu = raw_smp_processor_id();
71 data = tr->data[cpu];
72 disabled = atomic_inc_return(&data->disabled);
73
74 if (likely(disabled == 1))
75 trace_function(tr, data, ip, parent_ip, flags, pc);
76
77 atomic_dec(&data->disabled);
78 ftrace_preempt_enable(resched);
79}
80
81static void
82function_trace_call(unsigned long ip, unsigned long parent_ip)
83{
84 struct trace_array *tr = func_trace;
85 struct trace_array_cpu *data;
86 unsigned long flags;
87 long disabled;
88 int cpu;
89 int pc;
90
91 if (unlikely(!ftrace_function_enabled))
92 return;
93
94 /*
95 * Need to use raw, since this must be called before the
96 * recursive protection is performed.
97 */
98 local_irq_save(flags);
99 cpu = raw_smp_processor_id();
100 data = tr->data[cpu];
101 disabled = atomic_inc_return(&data->disabled);
102
103 if (likely(disabled == 1)) {
104 pc = preempt_count();
105 trace_function(tr, data, ip, parent_ip, flags, pc);
106 }
107
108 atomic_dec(&data->disabled);
109 local_irq_restore(flags);
110}
111
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112static void
113function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
114{
115 struct trace_array *tr = func_trace;
116 struct trace_array_cpu *data;
117 unsigned long flags;
118 long disabled;
119 int cpu;
120 int pc;
121
122 if (unlikely(!ftrace_function_enabled))
123 return;
124
125 /*
126 * Need to use raw, since this must be called before the
127 * recursive protection is performed.
128 */
129 local_irq_save(flags);
130 cpu = raw_smp_processor_id();
131 data = tr->data[cpu];
132 disabled = atomic_inc_return(&data->disabled);
133
134 if (likely(disabled == 1)) {
135 pc = preempt_count();
136 /*
137 * skip over 5 funcs:
138 * __ftrace_trace_stack,
139 * __trace_stack,
140 * function_stack_trace_call
141 * ftrace_list_func
142 * ftrace_call
143 */
144 __trace_stack(tr, data, flags, 5, pc);
145 }
146
147 atomic_dec(&data->disabled);
148 local_irq_restore(flags);
149}
150
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151
152static struct ftrace_ops trace_ops __read_mostly =
153{
154 .func = function_trace_call,
155};
156
157void tracing_start_function_trace(void)
158{
159 ftrace_function_enabled = 0;
160
161 if (trace_flags & TRACE_ITER_PREEMPTONLY)
162 trace_ops.func = function_trace_call_preempt_only;
163 else
164 trace_ops.func = function_trace_call;
165
166 register_ftrace_function(&trace_ops);
167 ftrace_function_enabled = 1;
168}
169
170void tracing_stop_function_trace(void)
171{
172 ftrace_function_enabled = 0;
173 unregister_ftrace_function(&trace_ops);
174}
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175static struct ftrace_ops trace_stack_ops __read_mostly =
176{
177 .func = function_stack_trace_call,
178};
179
180/* Our two options */
181enum {
182 TRACE_FUNC_OPT_STACK = 0x1,
183};
184
185static struct tracer_opt func_opts[] = {
186#ifdef CONFIG_STACKTRACE
187 { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
188#endif
189 { } /* Always set a last empty entry */
190};
191
192static struct tracer_flags func_flags = {
193 .val = 0, /* By default: all flags disabled */
194 .opts = func_opts
195};
196
197static int func_set_flag(u32 old_flags, u32 bit, int set)
198{
199 if (bit == TRACE_FUNC_OPT_STACK) {
200 /* do nothing if already set */
201 if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
202 return 0;
203
204 if (set)
205 register_ftrace_function(&trace_stack_ops);
206 else
207 unregister_ftrace_function(&trace_stack_ops);
208
209 return 0;
210 }
211
212 return -EINVAL;
213}
214
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215static struct tracer function_trace __read_mostly =
216{
3ce83aea 217 .name = "function",
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218 .init = function_trace_init,
219 .reset = function_trace_reset,
9036990d 220 .start = function_trace_start,
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221 .flags = &func_flags,
222 .set_flag = func_set_flag,
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223#ifdef CONFIG_FTRACE_SELFTEST
224 .selftest = trace_selftest_startup_function,
225#endif
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226};
227
228static __init int init_function_trace(void)
229{
230 return register_tracer(&function_trace);
231}
232
233device_initcall(init_function_trace);