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1/*
2 * kdb helper for dumping the ftrace buffer
3 *
4 * Copyright (C) 2010 Jason Wessel <jason.wessel@windriver.com>
5 *
6 * ftrace_dump_buf based on ftrace_dump:
7 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
8 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
9 *
10 */
11#include <linux/init.h>
12#include <linux/kgdb.h>
13#include <linux/kdb.h>
14#include <linux/ftrace.h>
15
16#include "trace.h"
17#include "trace_output.h"
18
19static void ftrace_dump_buf(int skip_lines, long cpu_file)
20{
21 /* use static because iter can be a bit big for the stack */
22 static struct trace_iterator iter;
23 static struct ring_buffer_iter *buffer_iter[CONFIG_NR_CPUS];
24 struct trace_array *tr;
25 unsigned int old_userobj;
26 int cnt = 0, cpu;
27
28 trace_init_global_iter(&iter);
29 iter.buffer_iter = buffer_iter;
30 tr = iter.tr;
31
32 for_each_tracing_cpu(cpu) {
33 atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
34 }
35
36 old_userobj = tr->trace_flags;
37
38 /* don't look at user memory in panic mode */
39 tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
40
41 kdb_printf("Dumping ftrace buffer:\n");
42
43 /* reset all but tr, trace, and overruns */
44 memset(&iter.seq, 0,
45 sizeof(struct trace_iterator) -
46 offsetof(struct trace_iterator, seq));
47 iter.iter_flags |= TRACE_FILE_LAT_FMT;
48 iter.pos = -1;
49
50 if (cpu_file == RING_BUFFER_ALL_CPUS) {
51 for_each_tracing_cpu(cpu) {
52 iter.buffer_iter[cpu] =
53 ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu);
54 ring_buffer_read_start(iter.buffer_iter[cpu]);
55 tracing_iter_reset(&iter, cpu);
56 }
57 } else {
58 iter.cpu_file = cpu_file;
59 iter.buffer_iter[cpu_file] =
60 ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file);
61 ring_buffer_read_start(iter.buffer_iter[cpu_file]);
62 tracing_iter_reset(&iter, cpu_file);
63 }
64
65 while (trace_find_next_entry_inc(&iter)) {
66 if (!cnt)
67 kdb_printf("---------------------------------\n");
68 cnt++;
69
70 if (!skip_lines) {
71 print_trace_line(&iter);
72 trace_printk_seq(&iter.seq);
73 } else {
74 skip_lines--;
75 }
76
77 if (KDB_FLAG(CMD_INTERRUPT))
78 goto out;
79 }
80
81 if (!cnt)
82 kdb_printf(" (ftrace buffer empty)\n");
83 else
84 kdb_printf("---------------------------------\n");
85
86out:
87 tr->trace_flags = old_userobj;
88
89 for_each_tracing_cpu(cpu) {
90 atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
91 }
92
93 for_each_tracing_cpu(cpu) {
94 if (iter.buffer_iter[cpu]) {
95 ring_buffer_read_finish(iter.buffer_iter[cpu]);
96 iter.buffer_iter[cpu] = NULL;
97 }
98 }
99}
100
101/*
102 * kdb_ftdump - Dump the ftrace log buffer
103 */
104static int kdb_ftdump(int argc, const char **argv)
105{
106 int skip_lines = 0;
107 long cpu_file;
108 char *cp;
109
110 if (argc > 2)
111 return KDB_ARGCOUNT;
112
113 if (argc) {
114 skip_lines = simple_strtol(argv[1], &cp, 0);
115 if (*cp)
116 skip_lines = 0;
117 }
118
119 if (argc == 2) {
120 cpu_file = simple_strtol(argv[2], &cp, 0);
121 if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 ||
122 !cpu_online(cpu_file))
123 return KDB_BADINT;
124 } else {
125 cpu_file = RING_BUFFER_ALL_CPUS;
126 }
127
128 kdb_trap_printk++;
129 ftrace_dump_buf(skip_lines, cpu_file);
130 kdb_trap_printk--;
131
132 return 0;
133}
134
135static __init int kdb_ftrace_register(void)
136{
137 kdb_register_flags("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
138 "Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE);
139 return 0;
140}
141
142late_initcall(kdb_ftrace_register);
1/*
2 * kdb helper for dumping the ftrace buffer
3 *
4 * Copyright (C) 2010 Jason Wessel <jason.wessel@windriver.com>
5 *
6 * ftrace_dump_buf based on ftrace_dump:
7 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
8 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
9 *
10 */
11#include <linux/init.h>
12#include <linux/kgdb.h>
13#include <linux/kdb.h>
14#include <linux/ftrace.h>
15
16#include "trace.h"
17#include "trace_output.h"
18
19static void ftrace_dump_buf(int skip_lines, long cpu_file)
20{
21 /* use static because iter can be a bit big for the stack */
22 static struct trace_iterator iter;
23 unsigned int old_userobj;
24 int cnt = 0, cpu;
25
26 trace_init_global_iter(&iter);
27
28 for_each_tracing_cpu(cpu) {
29 atomic_inc(&iter.tr->data[cpu]->disabled);
30 }
31
32 old_userobj = trace_flags;
33
34 /* don't look at user memory in panic mode */
35 trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
36
37 kdb_printf("Dumping ftrace buffer:\n");
38
39 /* reset all but tr, trace, and overruns */
40 memset(&iter.seq, 0,
41 sizeof(struct trace_iterator) -
42 offsetof(struct trace_iterator, seq));
43 iter.iter_flags |= TRACE_FILE_LAT_FMT;
44 iter.pos = -1;
45
46 if (cpu_file == TRACE_PIPE_ALL_CPU) {
47 for_each_tracing_cpu(cpu) {
48 iter.buffer_iter[cpu] =
49 ring_buffer_read_prepare(iter.tr->buffer, cpu);
50 ring_buffer_read_start(iter.buffer_iter[cpu]);
51 tracing_iter_reset(&iter, cpu);
52 }
53 } else {
54 iter.cpu_file = cpu_file;
55 iter.buffer_iter[cpu_file] =
56 ring_buffer_read_prepare(iter.tr->buffer, cpu_file);
57 ring_buffer_read_start(iter.buffer_iter[cpu_file]);
58 tracing_iter_reset(&iter, cpu_file);
59 }
60 if (!trace_empty(&iter))
61 trace_find_next_entry_inc(&iter);
62 while (!trace_empty(&iter)) {
63 if (!cnt)
64 kdb_printf("---------------------------------\n");
65 cnt++;
66
67 if (trace_find_next_entry_inc(&iter) != NULL && !skip_lines)
68 print_trace_line(&iter);
69 if (!skip_lines)
70 trace_printk_seq(&iter.seq);
71 else
72 skip_lines--;
73 if (KDB_FLAG(CMD_INTERRUPT))
74 goto out;
75 }
76
77 if (!cnt)
78 kdb_printf(" (ftrace buffer empty)\n");
79 else
80 kdb_printf("---------------------------------\n");
81
82out:
83 trace_flags = old_userobj;
84
85 for_each_tracing_cpu(cpu) {
86 atomic_dec(&iter.tr->data[cpu]->disabled);
87 }
88
89 for_each_tracing_cpu(cpu)
90 if (iter.buffer_iter[cpu])
91 ring_buffer_read_finish(iter.buffer_iter[cpu]);
92}
93
94/*
95 * kdb_ftdump - Dump the ftrace log buffer
96 */
97static int kdb_ftdump(int argc, const char **argv)
98{
99 int skip_lines = 0;
100 long cpu_file;
101 char *cp;
102
103 if (argc > 2)
104 return KDB_ARGCOUNT;
105
106 if (argc) {
107 skip_lines = simple_strtol(argv[1], &cp, 0);
108 if (*cp)
109 skip_lines = 0;
110 }
111
112 if (argc == 2) {
113 cpu_file = simple_strtol(argv[2], &cp, 0);
114 if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 ||
115 !cpu_online(cpu_file))
116 return KDB_BADINT;
117 } else {
118 cpu_file = TRACE_PIPE_ALL_CPU;
119 }
120
121 kdb_trap_printk++;
122 ftrace_dump_buf(skip_lines, cpu_file);
123 kdb_trap_printk--;
124
125 return 0;
126}
127
128static __init int kdb_ftrace_register(void)
129{
130 kdb_register_repeat("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
131 "Dump ftrace log", 0, KDB_REPEAT_NONE);
132 return 0;
133}
134
135late_initcall(kdb_ftrace_register);