check_allocation_funcs.c

   1 /*
   2  * sparse/check_allocation_funcs.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include <fcntl.h>
  11 #include <unistd.h>
  12 #include "parse.h"
  13 #include "smatch.h"
  14 #include "smatch_slist.h"
  15
  16 static int my_id;
  17
  18 /*
  19  * Print a list of functions that return newly allocated memory.
  20  */
  21
  22 static struct tracker_list *allocated;
  23
  24 static const char *allocation_funcs[] = {
  25         "malloc",
  26         "kmalloc",
  27         "kzalloc",
  28         NULL,
  29 };
  30
  31 static void match_allocation(const char *fn, struct expression *expr,
  32                              void *info)
  33 {
  34         char *left_name;
  35         struct symbol *left_sym;
  36
  37         left_name = get_variable_from_expr(expr->left, &left_sym);
  38         if (!left_name || !left_sym)
  39                 goto free;
  40         if (left_sym->ctype.modifiers &
  41             (MOD_NONLOCAL | MOD_STATIC | MOD_ADDRESSABLE))
  42                 goto free;
  43         add_tracker(&allocated, left_name, my_id, left_sym);
  44 free:
  45         free_string(left_name);
  46 }
  47
  48 static int returns_new_stuff = 0;
  49 static int returns_old_stuff = 0;
  50 static void match_return(struct statement *stmt)
  51 {
  52         char *name;
  53         struct symbol *sym;
  54
  55         if (get_value(stmt->ret_value) == 0)
  56                 return;
  57         returns_new_stuff = 1;
  58         name = get_variable_from_expr(stmt->ret_value, &sym);
  59         if (!name || !sym) {
  60                 returns_old_stuff = 1;
  61                 goto free;
  62         }
  63         if (!in_tracker_list(allocated, name, my_id, sym))
  64                 returns_old_stuff = 1;
  65 free:
  66         free_string(name);
  67 }
  68
  69 static void match_end_func(struct symbol *sym)
  70 {
  71         if (returns_new_stuff && !returns_old_stuff)
  72                 smatch_msg("info: allocation func");
  73         free_trackers_and_list(&allocated);
  74         returns_new_stuff = 0;
  75         returns_old_stuff = 0;
  76 }
  77
  78 void check_allocation_funcs(int id)
  79 {
  80         int i;
  81
  82         my_id = id;
  83         add_hook(&match_return, RETURN_HOOK);
  84         add_hook(&match_end_func, END_FUNC_HOOK);
  85         for(i = 0; allocation_funcs[i]; i++) {
  86                 add_function_assign_hook(allocation_funcs[i],
  87                                          &match_allocation, NULL);
  88         }
  89 }