projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| fb52607a FW |
1 | /* |
| 2 | * | |
| 3 | * Function graph tracer. | |
| 4 | * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com> | |
| 5 | * Mostly borrowed from function tracer which | |
| 6 | * is Copyright (c) Steven Rostedt <srostedt@redhat.com> | |
| 7 | * | |
| 8 | */ | |
| 9 | #include <linux/debugfs.h> | |
| 10 | #include <linux/uaccess.h> | |
| 11 | #include <linux/ftrace.h> | |
| 12 | #include <linux/fs.h> | |
| 13 | ||
| 14 | #include "trace.h" | |
| 15 | ||
| 16 | ||
| 17 | #define TRACE_GRAPH_PRINT_OVERRUN 0x1 | |
| 18 | static struct tracer_opt trace_opts[] = { | |
| 19 | /* Display overruns or not */ | |
| 20 | { TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) }, | |
| 21 | { } /* Empty entry */ | |
| 22 | }; | |
| 23 | ||
| 24 | static struct tracer_flags tracer_flags = { | |
| 25 | .val = 0, /* Don't display overruns by default */ | |
| 26 | .opts = trace_opts | |
| 27 | }; | |
| 28 | ||
| 29 | ||
| 30 | static int graph_trace_init(struct trace_array *tr) | |
| 31 | { | |
| 32 | int cpu; | |
| 33 | for_each_online_cpu(cpu) | |
| 34 | tracing_reset(tr, cpu); | |
| 35 | ||
| 36 | return register_ftrace_graph(&trace_function_graph); | |
| 37 | } | |
| 38 | ||
| 39 | static void graph_trace_reset(struct trace_array *tr) | |
| 40 | { | |
| 41 | unregister_ftrace_graph(); | |
| 42 | } | |
| 43 | ||
| 44 | ||
| 45 | enum print_line_t | |
| 46 | print_graph_function(struct trace_iterator *iter) | |
| 47 | { | |
| 48 | struct trace_seq *s = &iter->seq; | |
| 49 | struct trace_entry *entry = iter->ent; | |
| 50 | struct ftrace_graph_entry *field; | |
| 51 | int ret; | |
| 52 | ||
| 53 | if (entry->type == TRACE_FN_RET) { | |
| 54 | trace_assign_type(field, entry); | |
| 55 | ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip); | |
| 56 | if (!ret) | |
| 57 | return TRACE_TYPE_PARTIAL_LINE; | |
| 58 | ||
| 59 | ret = seq_print_ip_sym(s, field->ip, | |
| 60 | trace_flags & TRACE_ITER_SYM_MASK); | |
| 61 | if (!ret) | |
| 62 | return TRACE_TYPE_PARTIAL_LINE; | |
| 63 | ||
| 64 | ret = trace_seq_printf(s, " (%llu ns)", | |
| 65 | field->rettime - field->calltime); | |
| 66 | if (!ret) | |
| 67 | return TRACE_TYPE_PARTIAL_LINE; | |
| 68 | ||
| 69 | if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { | |
| 70 | ret = trace_seq_printf(s, " (Overruns: %lu)", | |
| 71 | field->overrun); | |
| 72 | if (!ret) | |
| 73 | return TRACE_TYPE_PARTIAL_LINE; | |
| 74 | } | |
| 75 | ||
| 76 | ret = trace_seq_printf(s, "\n"); | |
| 77 | if (!ret) | |
| 78 | return TRACE_TYPE_PARTIAL_LINE; | |
| 79 | ||
| 80 | return TRACE_TYPE_HANDLED; | |
| 81 | } | |
| 82 | return TRACE_TYPE_UNHANDLED; | |
| 83 | } | |
| 84 | ||
| 85 | static struct tracer graph_trace __read_mostly = { | |
| 86 | .name = "function-graph", | |
| 87 | .init = graph_trace_init, | |
| 88 | .reset = graph_trace_reset, | |
| 89 | .print_line = print_graph_function, | |
| 90 | .flags = &tracer_flags, | |
| 91 | }; | |
| 92 | ||
| 93 | static __init int init_graph_trace(void) | |
| 94 | { | |
| 95 | return register_tracer(&graph_trace); | |
| 96 | } | |
| 97 | ||
| 98 | device_initcall(init_graph_trace); |