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 const char *allocation_funcs[] = {
  33         "kmalloc",
  34         "kmalloc_node",
  35         "kzalloc",
  36         "kzalloc_node",
  37         "vmalloc",
  38         "vzalloc",
  39         "__vmalloc",
  40         "kvmalloc",
  41         "kcalloc",
  42         "__alloc_skb",
  43         "kvcalloc",
  44         "kmalloc_array",
  45         "devm_kmalloc_array",
  46         "sock_kmalloc",
  47         "kmemdup",
  48         "kmemdup_user",
  49         "dma_alloc_attrs",
  50         "pci_alloc_consistent",
  51         "pci_alloc_coherent",
  52         "devm_kmalloc",
  53         "devm_kzalloc",
  54         "krealloc",
  55         "__alloc_bootmem",
  56         "alloc_bootmem",
  57         "get_zeroed_page",
  58         "alloc_page",
  59         "alloc_pages",
  60         "alloc_pages_current",
  61         "__get_free_pages",
  62         "dma_alloc_contiguous",
  63         "dma_alloc_coherent",
  64         NULL,
  65 };
  66
  67 static void match_allocation(const char *fn, struct expression *expr,
  68                              void *info)
  69 {
  70         char *left_name;
  71         struct symbol *left_sym;
  72
  73         left_name = expr_to_var_sym(expr->left, &left_sym);
  74         if (!left_name || !left_sym)
  75                 goto free;
  76         if (left_sym->ctype.modifiers &
  77             (MOD_NONLOCAL | MOD_STATIC | MOD_ADDRESSABLE))
  78                 goto free;
  79         add_tracker(&allocated, my_id, left_name, left_sym);
  80 free:
  81         free_string(left_name);
  82 }
  83
  84 static int returns_new_stuff = 0;
  85 static int returns_old_stuff = 0;
  86 static void match_return(struct expression *ret_value)
  87 {
  88         char *name;
  89         struct symbol *sym;
  90         sval_t tmp;
  91
  92         if (__inline_fn)
  93                 return;
  94         if (get_value(ret_value, &tmp) && tmp.value == 0)
  95                 return;
  96         returns_new_stuff = 1;
  97         name = expr_to_var_sym(ret_value, &sym);
  98         if (!name || !sym) {
  99                 returns_old_stuff = 1;
 100                 goto free;
 101         }
 102         if (!in_tracker_list(allocated, my_id, name, sym))
 103                 returns_old_stuff = 1;
 104 free:
 105         free_string(name);
 106 }
 107
 108 static void match_end_func(struct symbol *sym)
 109 {
 110         if (__inline_fn)
 111                 return;
 112         if (returns_new_stuff && !returns_old_stuff)
 113                 sm_info("allocation func");
 114         free_trackers_and_list(&allocated);
 115         returns_new_stuff = 0;
 116         returns_old_stuff = 0;
 117 }
 118
 119 void check_allocation_funcs(int id)
 120 {
 121         int i;
 122
 123         if (!option_info || option_project != PROJ_KERNEL)
 124                 return;
 125
 126         my_id = id;
 127         add_hook(&match_return, RETURN_HOOK);
 128         add_hook(&match_end_func, AFTER_FUNC_HOOK);
 129         for (i = 0; allocation_funcs[i]; i++) {
 130                 add_function_assign_hook(allocation_funcs[i],
 131                                          &match_allocation, NULL);
 132         }
 133 }