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 = 0;
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}