diff options
Diffstat (limited to 'kernel/trace/trace_nop.c')
-rw-r--r-- | kernel/trace/trace_nop.c | 65 |
1 files changed, 53 insertions, 12 deletions
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 4592b4862515..b9767acd30ac 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c | |||
@@ -12,6 +12,27 @@ | |||
12 | 12 | ||
13 | #include "trace.h" | 13 | #include "trace.h" |
14 | 14 | ||
15 | /* Our two options */ | ||
16 | enum { | ||
17 | TRACE_NOP_OPT_ACCEPT = 0x1, | ||
18 | TRACE_NOP_OPT_REFUSE = 0x2 | ||
19 | }; | ||
20 | |||
21 | /* Options for the tracer (see trace_options file) */ | ||
22 | static struct tracer_opt nop_opts[] = { | ||
23 | /* Option that will be accepted by set_flag callback */ | ||
24 | { TRACER_OPT(test_nop_accept, TRACE_NOP_OPT_ACCEPT) }, | ||
25 | /* Option that will be refused by set_flag callback */ | ||
26 | { TRACER_OPT(test_nop_refuse, TRACE_NOP_OPT_REFUSE) }, | ||
27 | { } /* Always set a last empty entry */ | ||
28 | }; | ||
29 | |||
30 | static struct tracer_flags nop_flags = { | ||
31 | /* You can check your flags value here when you want. */ | ||
32 | .val = 0, /* By default: all flags disabled */ | ||
33 | .opts = nop_opts | ||
34 | }; | ||
35 | |||
15 | static struct trace_array *ctx_trace; | 36 | static struct trace_array *ctx_trace; |
16 | 37 | ||
17 | static void start_nop_trace(struct trace_array *tr) | 38 | static void start_nop_trace(struct trace_array *tr) |
@@ -24,7 +45,7 @@ static void stop_nop_trace(struct trace_array *tr) | |||
24 | /* Nothing to do! */ | 45 | /* Nothing to do! */ |
25 | } | 46 | } |
26 | 47 | ||
27 | static void nop_trace_init(struct trace_array *tr) | 48 | static int nop_trace_init(struct trace_array *tr) |
28 | { | 49 | { |
29 | int cpu; | 50 | int cpu; |
30 | ctx_trace = tr; | 51 | ctx_trace = tr; |
@@ -32,33 +53,53 @@ static void nop_trace_init(struct trace_array *tr) | |||
32 | for_each_online_cpu(cpu) | 53 | for_each_online_cpu(cpu) |
33 | tracing_reset(tr, cpu); | 54 | tracing_reset(tr, cpu); |
34 | 55 | ||
35 | if (tr->ctrl) | 56 | start_nop_trace(tr); |
36 | start_nop_trace(tr); | 57 | return 0; |
37 | } | 58 | } |
38 | 59 | ||
39 | static void nop_trace_reset(struct trace_array *tr) | 60 | static void nop_trace_reset(struct trace_array *tr) |
40 | { | 61 | { |
41 | if (tr->ctrl) | 62 | stop_nop_trace(tr); |
42 | stop_nop_trace(tr); | ||
43 | } | 63 | } |
44 | 64 | ||
45 | static void nop_trace_ctrl_update(struct trace_array *tr) | 65 | /* It only serves as a signal handler and a callback to |
66 | * accept or refuse tthe setting of a flag. | ||
67 | * If you don't implement it, then the flag setting will be | ||
68 | * automatically accepted. | ||
69 | */ | ||
70 | static int nop_set_flag(u32 old_flags, u32 bit, int set) | ||
46 | { | 71 | { |
47 | /* When starting a new trace, reset the buffers */ | 72 | /* |
48 | if (tr->ctrl) | 73 | * Note that you don't need to update nop_flags.val yourself. |
49 | start_nop_trace(tr); | 74 | * The tracing Api will do it automatically if you return 0 |
50 | else | 75 | */ |
51 | stop_nop_trace(tr); | 76 | if (bit == TRACE_NOP_OPT_ACCEPT) { |
77 | printk(KERN_DEBUG "nop_test_accept flag set to %d: we accept." | ||
78 | " Now cat trace_options to see the result\n", | ||
79 | set); | ||
80 | return 0; | ||
81 | } | ||
82 | |||
83 | if (bit == TRACE_NOP_OPT_REFUSE) { | ||
84 | printk(KERN_DEBUG "nop_test_refuse flag set to %d: we refuse." | ||
85 | "Now cat trace_options to see the result\n", | ||
86 | set); | ||
87 | return -EINVAL; | ||
88 | } | ||
89 | |||
90 | return 0; | ||
52 | } | 91 | } |
53 | 92 | ||
93 | |||
54 | struct tracer nop_trace __read_mostly = | 94 | struct tracer nop_trace __read_mostly = |
55 | { | 95 | { |
56 | .name = "nop", | 96 | .name = "nop", |
57 | .init = nop_trace_init, | 97 | .init = nop_trace_init, |
58 | .reset = nop_trace_reset, | 98 | .reset = nop_trace_reset, |
59 | .ctrl_update = nop_trace_ctrl_update, | ||
60 | #ifdef CONFIG_FTRACE_SELFTEST | 99 | #ifdef CONFIG_FTRACE_SELFTEST |
61 | .selftest = trace_selftest_startup_nop, | 100 | .selftest = trace_selftest_startup_nop, |
62 | #endif | 101 | #endif |
102 | .flags = &nop_flags, | ||
103 | .set_flag = nop_set_flag | ||
63 | }; | 104 | }; |
64 | 105 | ||