tools/lib/traceevent/plugin_function.c

   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
  27 static struct func_stack {
  28         int size;
  29         char **stack;
  30 } *fstack;
  31
  32 static int cpus = -1;
  33
  34 #define STK_BLK 10
  35
  36 struct 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
  56 static struct pevent_plugin_option *ftrace_parent = &plugin_options[0];
  57 static struct pevent_plugin_option *ftrace_indent = &plugin_options[1];
  58
  59 static 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
  88 static 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
 125 static 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
 166 int 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
 176 void 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 }