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
 36static void add_child(struct func_stack *stack, const char *child, int pos)
 37{
 38	int i;
 39
 40	if (!child)
 41		return;
 42
 43	if (pos < stack->size)
 44		free(stack->stack[pos]);
 45	else {
 46		char **ptr;
 47
 48		ptr = realloc(stack->stack, sizeof(char *) *
 49			      (stack->size + STK_BLK));
 50		if (!ptr) {
 51			warning("could not allocate plugin memory\n");
 52			return;
 53		}
 54
 55		stack->stack = ptr;
 56
 57		for (i = stack->size; i < stack->size + STK_BLK; i++)
 58			stack->stack[i] = NULL;
 59		stack->size += STK_BLK;
 60	}
 61
 62	stack->stack[pos] = strdup(child);
 63}
 64
 65static int add_and_get_index(const char *parent, const char *child, int cpu)
 66{
 67	int i;
 68
 69	if (cpu < 0)
 70		return 0;
 71
 72	if (cpu > cpus) {
 73		struct func_stack *ptr;
 74
 75		ptr = realloc(fstack, sizeof(*fstack) * (cpu + 1));
 76		if (!ptr) {
 77			warning("could not allocate plugin memory\n");
 78			return 0;
 79		}
 80
 81		fstack = ptr;
 82
 83		/* Account for holes in the cpu count */
 84		for (i = cpus + 1; i <= cpu; i++)
 85			memset(&fstack[i], 0, sizeof(fstack[i]));
 86		cpus = cpu;
 87	}
 88
 89	for (i = 0; i < fstack[cpu].size && fstack[cpu].stack[i]; i++) {
 90		if (strcmp(parent, fstack[cpu].stack[i]) == 0) {
 91			add_child(&fstack[cpu], child, i+1);
 92			return i;
 93		}
 94	}
 95
 96	/* Not found */
 97	add_child(&fstack[cpu], parent, 0);
 98	add_child(&fstack[cpu], child, 1);
 99	return 0;
100}
101
102static int function_handler(struct trace_seq *s, struct pevent_record *record,
103			    struct event_format *event, void *context)
104{
105	struct pevent *pevent = event->pevent;
106	unsigned long long function;
107	unsigned long long pfunction;
108	const char *func;
109	const char *parent;
110	int index;
111
112	if (pevent_get_field_val(s, event, "ip", record, &function, 1))
113		return trace_seq_putc(s, '!');
114
115	func = pevent_find_function(pevent, function);
116
117	if (pevent_get_field_val(s, event, "parent_ip", record, &pfunction, 1))
118		return trace_seq_putc(s, '!');
119
120	parent = pevent_find_function(pevent, pfunction);
121
122	index = add_and_get_index(parent, func, record->cpu);
123
124	trace_seq_printf(s, "%*s", index*3, "");
125
126	if (func)
127		trace_seq_printf(s, "%s", func);
128	else
129		trace_seq_printf(s, "0x%llx", function);
130
131	trace_seq_printf(s, " <-- ");
132	if (parent)
133		trace_seq_printf(s, "%s", parent);
134	else
135		trace_seq_printf(s, "0x%llx", pfunction);
136
137	return 0;
138}
139
140int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
141{
142	pevent_register_event_handler(pevent, -1, "ftrace", "function",
143				      function_handler, NULL);
144	return 0;
145}
146
147void PEVENT_PLUGIN_UNLOADER(struct pevent *pevent)
148{
149	int i, x;
150
151	pevent_unregister_event_handler(pevent, -1, "ftrace", "function",
152					function_handler, NULL);
153
154	for (i = 0; i <= cpus; i++) {
155		for (x = 0; x < fstack[i].size && fstack[i].stack[x]; x++)
156			free(fstack[i].stack[x]);
157		free(fstack[i].stack);
158	}
159
160	free(fstack);
161	fstack = NULL;
162	cpus = -1;
163}