Commit | Line | Data |
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955b61e5 JW |
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 | ||
955b61e5 JW |
16 | #include "trace.h" |
17 | #include "trace_output.h" | |
18 | ||
19063c77 | 19 | static void ftrace_dump_buf(int skip_lines, long cpu_file) |
955b61e5 JW |
20 | { |
21 | /* use static because iter can be a bit big for the stack */ | |
22 | static struct trace_iterator iter; | |
c270cc75 | 23 | static struct ring_buffer_iter *buffer_iter[CONFIG_NR_CPUS]; |
955b61e5 JW |
24 | unsigned int old_userobj; |
25 | int cnt = 0, cpu; | |
26 | ||
27 | trace_init_global_iter(&iter); | |
c270cc75 | 28 | iter.buffer_iter = buffer_iter; |
955b61e5 JW |
29 | |
30 | for_each_tracing_cpu(cpu) { | |
12883efb | 31 | atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); |
955b61e5 JW |
32 | } |
33 | ||
34 | old_userobj = trace_flags; | |
35 | ||
36 | /* don't look at user memory in panic mode */ | |
37 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
38 | ||
39 | kdb_printf("Dumping ftrace buffer:\n"); | |
40 | ||
41 | /* reset all but tr, trace, and overruns */ | |
42 | memset(&iter.seq, 0, | |
43 | sizeof(struct trace_iterator) - | |
44 | offsetof(struct trace_iterator, seq)); | |
45 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
46 | iter.pos = -1; | |
47 | ||
ae3b5093 | 48 | if (cpu_file == RING_BUFFER_ALL_CPUS) { |
19063c77 JW |
49 | for_each_tracing_cpu(cpu) { |
50 | iter.buffer_iter[cpu] = | |
12883efb | 51 | ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu); |
19063c77 JW |
52 | ring_buffer_read_start(iter.buffer_iter[cpu]); |
53 | tracing_iter_reset(&iter, cpu); | |
54 | } | |
55 | } else { | |
56 | iter.cpu_file = cpu_file; | |
57 | iter.buffer_iter[cpu_file] = | |
12883efb | 58 | ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file); |
19063c77 JW |
59 | ring_buffer_read_start(iter.buffer_iter[cpu_file]); |
60 | tracing_iter_reset(&iter, cpu_file); | |
955b61e5 | 61 | } |
8520dedb DT |
62 | |
63 | while (trace_find_next_entry_inc(&iter)) { | |
955b61e5 JW |
64 | if (!cnt) |
65 | kdb_printf("---------------------------------\n"); | |
66 | cnt++; | |
67 | ||
8520dedb | 68 | if (!skip_lines) { |
955b61e5 | 69 | print_trace_line(&iter); |
955b61e5 | 70 | trace_printk_seq(&iter.seq); |
8520dedb | 71 | } else { |
955b61e5 | 72 | skip_lines--; |
8520dedb DT |
73 | } |
74 | ||
955b61e5 JW |
75 | if (KDB_FLAG(CMD_INTERRUPT)) |
76 | goto out; | |
77 | } | |
78 | ||
79 | if (!cnt) | |
80 | kdb_printf(" (ftrace buffer empty)\n"); | |
81 | else | |
82 | kdb_printf("---------------------------------\n"); | |
83 | ||
84 | out: | |
85 | trace_flags = old_userobj; | |
86 | ||
87 | for_each_tracing_cpu(cpu) { | |
12883efb | 88 | atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); |
955b61e5 JW |
89 | } |
90 | ||
c270cc75 DT |
91 | for_each_tracing_cpu(cpu) { |
92 | if (iter.buffer_iter[cpu]) { | |
955b61e5 | 93 | ring_buffer_read_finish(iter.buffer_iter[cpu]); |
c270cc75 DT |
94 | iter.buffer_iter[cpu] = NULL; |
95 | } | |
96 | } | |
955b61e5 JW |
97 | } |
98 | ||
99 | /* | |
100 | * kdb_ftdump - Dump the ftrace log buffer | |
101 | */ | |
102 | static int kdb_ftdump(int argc, const char **argv) | |
103 | { | |
104 | int skip_lines = 0; | |
19063c77 | 105 | long cpu_file; |
955b61e5 JW |
106 | char *cp; |
107 | ||
19063c77 | 108 | if (argc > 2) |
955b61e5 JW |
109 | return KDB_ARGCOUNT; |
110 | ||
111 | if (argc) { | |
112 | skip_lines = simple_strtol(argv[1], &cp, 0); | |
113 | if (*cp) | |
114 | skip_lines = 0; | |
115 | } | |
116 | ||
19063c77 JW |
117 | if (argc == 2) { |
118 | cpu_file = simple_strtol(argv[2], &cp, 0); | |
119 | if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 || | |
120 | !cpu_online(cpu_file)) | |
121 | return KDB_BADINT; | |
122 | } else { | |
ae3b5093 | 123 | cpu_file = RING_BUFFER_ALL_CPUS; |
19063c77 JW |
124 | } |
125 | ||
955b61e5 | 126 | kdb_trap_printk++; |
19063c77 | 127 | ftrace_dump_buf(skip_lines, cpu_file); |
955b61e5 JW |
128 | kdb_trap_printk--; |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | static __init int kdb_ftrace_register(void) | |
134 | { | |
42c884c1 | 135 | kdb_register_flags("ftdump", kdb_ftdump, "[skip_#lines] [cpu]", |
9452e977 | 136 | "Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE); |
955b61e5 JW |
137 | return 0; |
138 | } | |
139 | ||
140 | late_initcall(kdb_ftrace_register); |