tools/lib/traceevent/plugins/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 #include "trace-seq.h"
  27
  28 static struct func_stack {
  29         int size;
  30         char **stack;
  31 } *fstack;
  32
  33 static int cpus = -1;
  34
  35 #define STK_BLK 10
  36
  37 struct 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
  57 static struct tep_plugin_option *ftrace_parent = &plugin_options[0];
  58 static struct tep_plugin_option *ftrace_indent = &plugin_options[1];
  59
  60 static 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
  89 static 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
 126 static 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
 167 int 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
 177 void 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 }