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#include "trace-seq.h"
 27
 28static struct func_stack {
 29	int size;
 30	char **stack;
 31} *fstack;
 32
 33static int cpus = -1;
 34
 35#define STK_BLK 10
 36
 37struct tep_plugin_option plugin_options[] =
 38{
 39	{
 40		.name = "parent",
 41		.plugin_alias = "ftrace",
 42		.description =
 43		"Print parent of functions for function events",
 44	},
 45	{
 46		.name = "indent",
 47		.plugin_alias = "ftrace",
 48		.description =
 49		"Try to show function call indents, based on parents",
 50		.set = 1,
 51	},
 52	{
 53		.name = NULL,
 54	}
 55};
 56
 57static struct tep_plugin_option *ftrace_parent = &plugin_options[0];
 58static struct tep_plugin_option *ftrace_indent = &plugin_options[1];
 59
 60static void add_child(struct func_stack *stack, const char *child, int pos)
 61{
 62	int i;
 63
 64	if (!child)
 65		return;
 66
 67	if (pos < stack->size)
 68		free(stack->stack[pos]);
 69	else {
 70		char **ptr;
 71
 72		ptr = realloc(stack->stack, sizeof(char *) *
 73			      (stack->size + STK_BLK));
 74		if (!ptr) {
 75			warning("could not allocate plugin memory\n");
 76			return;
 77		}
 78
 79		stack->stack = ptr;
 80
 81		for (i = stack->size; i < stack->size + STK_BLK; i++)
 82			stack->stack[i] = NULL;
 83		stack->size += STK_BLK;
 84	}
 85
 86	stack->stack[pos] = strdup(child);
 87}
 88
 89static int add_and_get_index(const char *parent, const char *child, int cpu)
 90{
 91	int i;
 92
 93	if (cpu < 0)
 94		return 0;
 95
 96	if (cpu > cpus) {
 97		struct func_stack *ptr;
 98
 99		ptr = realloc(fstack, sizeof(*fstack) * (cpu + 1));
100		if (!ptr) {
101			warning("could not allocate plugin memory\n");
102			return 0;
103		}
104
105		fstack = ptr;
106
107		/* Account for holes in the cpu count */
108		for (i = cpus + 1; i <= cpu; i++)
109			memset(&fstack[i], 0, sizeof(fstack[i]));
110		cpus = cpu;
111	}
112
113	for (i = 0; i < fstack[cpu].size && fstack[cpu].stack[i]; i++) {
114		if (strcmp(parent, fstack[cpu].stack[i]) == 0) {
115			add_child(&fstack[cpu], child, i+1);
116			return i;
117		}
118	}
119
120	/* Not found */
121	add_child(&fstack[cpu], parent, 0);
122	add_child(&fstack[cpu], child, 1);
123	return 0;
124}
125
126static int function_handler(struct trace_seq *s, struct tep_record *record,
127			    struct tep_event *event, void *context)
128{
129	struct tep_handle *tep = event->tep;
130	unsigned long long function;
131	unsigned long long pfunction;
132	const char *func;
133	const char *parent;
134	int index = 0;
135
136	if (tep_get_field_val(s, event, "ip", record, &function, 1))
137		return trace_seq_putc(s, '!');
138
139	func = tep_find_function(tep, function);
140
141	if (tep_get_field_val(s, event, "parent_ip", record, &pfunction, 1))
142		return trace_seq_putc(s, '!');
143
144	parent = tep_find_function(tep, pfunction);
145
146	if (parent && ftrace_indent->set)
147		index = add_and_get_index(parent, func, record->cpu);
148
149	trace_seq_printf(s, "%*s", index*3, "");
150
151	if (func)
152		trace_seq_printf(s, "%s", func);
153	else
154		trace_seq_printf(s, "0x%llx", function);
155
156	if (ftrace_parent->set) {
157		trace_seq_printf(s, " <-- ");
158		if (parent)
159			trace_seq_printf(s, "%s", parent);
160		else
161			trace_seq_printf(s, "0x%llx", pfunction);
162	}
163
164	return 0;
165}
166
167int TEP_PLUGIN_LOADER(struct tep_handle *tep)
168{
169	tep_register_event_handler(tep, -1, "ftrace", "function",
170				   function_handler, NULL);
171
172	tep_plugin_add_options("ftrace", plugin_options);
173
174	return 0;
175}
176
177void TEP_PLUGIN_UNLOADER(struct tep_handle *tep)
178{
179	int i, x;
180
181	tep_unregister_event_handler(tep, -1, "ftrace", "function",
182				     function_handler, NULL);
183
184	for (i = 0; i <= cpus; i++) {
185		for (x = 0; x < fstack[i].size && fstack[i].stack[x]; x++)
186			free(fstack[i].stack[x]);
187		free(fstack[i].stack);
188	}
189
190	tep_plugin_remove_options(plugin_options);
191
192	free(fstack);
193	fstack = NULL;
194	cpus = -1;
195}