check_err_ptr.c

   1 /*
   2  * sparse/check_err_ptr.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * Functions should never return both NULL and ERR_PTR().
  12  */
  13
  14 #include "smatch.h"
  15 #include "smatch_slist.h"
  16
  17 static int my_id;
  18
  19 static struct symbol *this_func;
  20 static int err_ptr = 0;
  21 static int returns_null = 0;
  22
  23 static void match_function_def(struct symbol *sym)
  24 {
  25         this_func = sym;
  26 }
  27
  28 static void match_err_ptr(const char *fn, struct expression *expr, void *info)
  29 {
  30         if (!err_ptr)
  31                 smatch_msg("info:  returns_err_ptr");
  32         err_ptr = 1;
  33 }
  34
  35 static void match_return(struct statement *stmt)
  36 {
  37         if (get_implied_value(stmt->ret_value) != 0)
  38                 return;
  39         if (!returns_null)
  40                 smatch_msg("info:  returns_null");
  41         returns_null = 1;
  42 }
  43
  44 static void match_end_func(struct symbol *sym)
  45 {
  46         err_ptr = 0;
  47         returns_null = 0;
  48 }
  49
  50 void check_err_ptr(int id)
  51 {
  52         my_id = id;
  53         add_hook(&match_function_def, FUNC_DEF_HOOK);
  54         add_function_hook("ERR_PTR", &match_err_ptr, NULL);
  55         add_hook(&match_return, RETURN_HOOK);
  56         add_hook(&match_end_func, END_FUNC_HOOK);
  57 }