check_kmalloc_to_bugon.c

   1 /*
   2  * smatch/check_kmalloc_to_bugon.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "smatch.h"
  11
  12 static int my_id;
  13
  14 extern int check_assigned_expr_id;
  15
  16 static int is_kmalloc_call(struct expression *expr)
  17 {
  18         if (expr->type != EXPR_CALL)
  19                 return 0;
  20         if (expr->fn->type != EXPR_SYMBOL)
  21                 return 0;
  22         if (!strcmp(expr->fn->symbol_name->name, "kmalloc"))
  23                 return 1;
  24         if (!strcmp(expr->fn->symbol_name->name, "kzalloc"))
  25                 return 1;
  26         return 0;
  27 }
  28
  29 static void match_condition(struct expression *expr)
  30 {
  31         char *macro;
  32         struct smatch_state *state;
  33         struct expression *right;
  34         char *name;
  35
  36         macro = get_macro_name(&expr->pos);
  37         if (!macro || strcmp(macro, "BUG_ON") != 0)
  38                 return;
  39         state = get_state_expr(check_assigned_expr_id, expr);
  40         if (!state || !state->data)
  41                 return;
  42         right = (struct expression *)state->data;
  43         if (!is_kmalloc_call(right))
  44                 return;
  45
  46         name = get_variable_from_expr(expr, NULL);
  47         sm_msg("warn: bug on allocation failure '%s'", name);
  48         free_string(name);
  49 }
  50
  51 void check_kmalloc_to_bugon(int id)
  52 {
  53         if (option_project != PROJ_KERNEL)
  54                 return;
  55         if (!option_spammy)
  56                 return;
  57         my_id = id;
  58         add_hook(&match_condition, CONDITION_HOOK);
  59 }