1/*
2 * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
3 *
4 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation;
8 * version 2.1 of the License (not later!)
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this program; if not,  see <http://www.gnu.org/licenses>
17 *
18 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19 */
20#include <stdio.h>
21#include <stdlib.h>
22#include <string.h>
23
24#include "event-parse.h"
25#include "event-utils.h"
26
27static struct func_stack {
28	int size;
29	char **stack;
30} *fstack;
31
32static int cpus = -1;
33
34#define STK_BLK 10
35
36struct pevent_plugin_option plugin_options[] =
37{
38	{
39		.name = "parent",
40		.plugin_alias = "ftrace",
41		.description =
42		"Print parent of functions for function events",
43	},
44	{
45		.name = "indent",
46		.plugin_alias = "ftrace",
47		.description =
48		"Try to show function call indents, based on parents",
49		.set = 1,
50	},
51	{
52		.name = NULL,
53	}
54};
55
56static struct pevent_plugin_option *ftrace_parent = &plugin_options[0];
57static struct pevent_plugin_option *ftrace_indent = &plugin_options[1];
58
59static void add_child(struct func_stack *stack, const char *child, int pos)
60{
61	int i;
62
63	if (!child)
64		return;
65
66	if (pos < stack->size)
67		free(stack->stack[pos]);
68	else {
69		char **ptr;
70
71		ptr = realloc(stack->stack, sizeof(char *) *
72			      (stack->size + STK_BLK));
73		if (!ptr) {
74			warning("could not allocate plugin memory\n");
75			return;
76		}
77
78		stack->stack = ptr;
79
80		for (i = stack->size; i < stack->size + STK_BLK; i++)
81			stack->stack[i] = NULL;
82		stack->size += STK_BLK;
83	}
84
85	stack->stack[pos] = strdup(child);
86}
87
88static int add_and_get_index(const char *parent, const char *child, int cpu)
89{
90	int i;
91
92	if (cpu < 0)
93		return 0;
94
95	if (cpu > cpus) {
96		struct func_stack *ptr;
97
98		ptr = realloc(fstack, sizeof(*fstack) * (cpu + 1));
99		if (!ptr) {
100			warning("could not allocate plugin memory\n");
101			return 0;
102		}
103
104		fstack = ptr;
105
106		/* Account for holes in the cpu count */
107		for (i = cpus + 1; i <= cpu; i++)
108			memset(&fstack[i], 0, sizeof(fstack[i]));
109		cpus = cpu;
110	}
111
112	for (i = 0; i < fstack[cpu].size && fstack[cpu].stack[i]; i++) {
113		if (strcmp(parent, fstack[cpu].stack[i]) == 0) {
114			add_child(&fstack[cpu], child, i+1);
115			return i;
116		}
117	}
118
119	/* Not found */
120	add_child(&fstack[cpu], parent, 0);
121	add_child(&fstack[cpu], child, 1);
122	return 0;
123}
124
125static int function_handler(struct trace_seq *s, struct pevent_record *record,
126			    struct event_format *event, void *context)
127{
128	struct pevent *pevent = event->pevent;
129	unsigned long long function;
130	unsigned long long pfunction;
131	const char *func;
132	const char *parent;
133	int index;
134
135	if (pevent_get_field_val(s, event, "ip", record, &function, 1))
136		return trace_seq_putc(s, '!');
137
138	func = pevent_find_function(pevent, function);
139
140	if (pevent_get_field_val(s, event, "parent_ip", record, &pfunction, 1))
141		return trace_seq_putc(s, '!');
142
143	parent = pevent_find_function(pevent, pfunction);
144
145	if (parent && ftrace_indent->set)
146		index = add_and_get_index(parent, func, record->cpu);
147
148	trace_seq_printf(s, "%*s", index*3, "");
149
150	if (func)
151		trace_seq_printf(s, "%s", func);
152	else
153		trace_seq_printf(s, "0x%llx", function);
154
155	if (ftrace_parent->set) {
156		trace_seq_printf(s, " <-- ");
157		if (parent)
158			trace_seq_printf(s, "%s", parent);
159		else
160			trace_seq_printf(s, "0x%llx", pfunction);
161	}
162
163	return 0;
164}
165
166int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
167{
168	pevent_register_event_handler(pevent, -1, "ftrace", "function",
169				      function_handler, NULL);
170
171	traceevent_plugin_add_options("ftrace", plugin_options);
172
173	return 0;
174}
175
176void PEVENT_PLUGIN_UNLOADER(struct pevent *pevent)
177{
178	int i, x;
179
180	pevent_unregister_event_handler(pevent, -1, "ftrace", "function",
181					function_handler, NULL);
182
183	for (i = 0; i <= cpus; i++) {
184		for (x = 0; x < fstack[i].size && fstack[i].stack[x]; x++)
185			free(fstack[i].stack[x]);
186		free(fstack[i].stack);
187	}
188
189	traceevent_plugin_remove_options(plugin_options);
190
191	free(fstack);
192	fstack = NULL;
193	cpus = -1;
194}
195