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