check_allocation_funcs.c

   1 /*
   2  * Copyright (C) 2009 Dan Carpenter.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 #include <fcntl.h>
  19 #include <unistd.h>
  20 #include "parse.h"
  21 #include "smatch.h"
  22 #include "smatch_slist.h"
  23
  24 static int my_id;
  25
  26 /*
  27  * Print a list of functions that return newly allocated memory.
  28  */
  29
  30 static struct tracker_list *allocated;
  31
  32 static void match_allocation(struct expression *expr,
  33                              const char *name, struct symbol *sym,
  34                              struct allocation_info *info)
  35 {
  36         if (!sym)
  37                 return;
  38         if (sym->ctype.modifiers & (MOD_NONLOCAL | MOD_STATIC | MOD_ADDRESSABLE))
  39                 return;
  40         add_tracker(&allocated, my_id, name, sym);
  41 }
  42
  43 static unsigned long returns_new_stuff;
  44 static unsigned long returns_old_stuff;
  45
  46 static void match_return(struct expression *ret_value)
  47 {
  48         char *name;
  49         struct symbol *sym;
  50         sval_t tmp;
  51
  52         if (__inline_fn)
  53                 return;
  54         if (get_value(ret_value, &tmp) && tmp.value == 0)
  55                 return;
  56         returns_new_stuff = 1;
  57         name = expr_to_var_sym(ret_value, &sym);
  58         if (!name || !sym) {
  59                 returns_old_stuff = 1;
  60                 goto free;
  61         }
  62         if (!in_tracker_list(allocated, my_id, name, sym))
  63                 returns_old_stuff = 1;
  64 free:
  65         free_string(name);
  66 }
  67
  68 static void match_end_func(struct symbol *sym)
  69 {
  70         if (__inline_fn)
  71                 return;
  72         if (returns_new_stuff && !returns_old_stuff)
  73                 sm_info("allocation func");
  74         free_trackers_and_list(&allocated);
  75 }
  76
  77 void check_allocation_funcs(int id)
  78 {
  79         if (!option_info || option_project != PROJ_KERNEL)
  80                 return;
  81
  82         my_id = id;
  83
  84         add_function_data(&returns_old_stuff);
  85         add_function_data(&returns_new_stuff);
  86
  87         add_allocation_hook(&match_allocation);
  88
  89         add_hook(&match_return, RETURN_HOOK);
  90         add_hook(&match_end_func, AFTER_FUNC_HOOK);
  91 }