2 * kdb helper for dumping the ftrace buffer
4 * Copyright (C) 2010 Jason Wessel <jason.wessel@windriver.com>
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>
11 #include <linux/init.h>
12 #include <linux/kgdb.h>
13 #include <linux/kdb.h>
14 #include <linux/ftrace.h>
16 #include "../debug/kdb/kdb_private.h"
18 #include "trace_output.h"
20 static void ftrace_dump_buf(int skip_lines)
22 /* use static because iter can be a bit big for the stack */
23 static struct trace_iterator iter;
24 unsigned int old_userobj;
27 trace_init_global_iter(&iter);
29 for_each_tracing_cpu(cpu) {
30 atomic_inc(&iter.tr->data[cpu]->disabled);
33 old_userobj = trace_flags;
35 /* don't look at user memory in panic mode */
36 trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
38 kdb_printf("Dumping ftrace buffer:\n");
40 /* reset all but tr, trace, and overruns */
42 sizeof(struct trace_iterator) -
43 offsetof(struct trace_iterator, seq));
44 iter.iter_flags |= TRACE_FILE_LAT_FMT;
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);
54 if (!trace_empty(&iter))
55 trace_find_next_entry_inc(&iter);
56 while (!trace_empty(&iter)) {
58 kdb_printf("---------------------------------\n");
61 if (trace_find_next_entry_inc(&iter) != NULL && !skip_lines)
62 print_trace_line(&iter);
64 trace_printk_seq(&iter.seq);
67 if (KDB_FLAG(CMD_INTERRUPT))
72 kdb_printf(" (ftrace buffer empty)\n");
74 kdb_printf("---------------------------------\n");
77 trace_flags = old_userobj;
79 for_each_tracing_cpu(cpu) {
80 atomic_dec(&iter.tr->data[cpu]->disabled);
83 for_each_tracing_cpu(cpu)
84 if (iter.buffer_iter[cpu])
85 ring_buffer_read_finish(iter.buffer_iter[cpu]);
89 * kdb_ftdump - Dump the ftrace log buffer
91 static int kdb_ftdump(int argc, const char **argv)
100 skip_lines = simple_strtol(argv[1], &cp, 0);
106 ftrace_dump_buf(skip_lines);
112 static __init int kdb_ftrace_register(void)
114 kdb_register_repeat("ftdump", kdb_ftdump, "", "Dump ftrace log",
119 late_initcall(kdb_ftrace_register);