check_puts_argument.c

   1 /*
   2  * sparse/check_puts_argument.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * This script is for finding functions like hcd_buffer_free() which free
  12  * their arguments.  After running it, add those functions to check_memory.c
  13  */
  14
  15 #include "smatch.h"
  16 #include "smatch_slist.h"
  17
  18 static int my_id;
  19
  20 STATE(putted);
  21
  22 static struct symbol *this_func;
  23 static struct tracker_list *putted_args = NULL;
  24
  25 static void match_function_def(struct symbol *sym)
  26 {
  27         this_func = sym;
  28 }
  29
  30 static int parent_is_arg(struct symbol *sym)
  31 {
  32         struct symbol *arg;
  33
  34         FOR_EACH_PTR(this_func->ctype.base_type->arguments, arg) {
  35                 if (sym == arg)
  36                         return 1;
  37         } END_FOR_EACH_PTR(arg);
  38         return 0;
  39 }
  40
  41 static void match_put(const char *fn, struct expression *expr, void *info)
  42 {
  43         struct expression *tmp;
  44         struct symbol *sym;
  45         char *name;
  46
  47         tmp = get_argument_from_call_expr(expr->args, 0);
  48         tmp = strip_expr(tmp);
  49         name = get_variable_from_expr(tmp, &sym);
  50         free_string(name);
  51         if (parent_is_arg(sym) && sym->ident)
  52                 set_state(my_id, sym->ident->name, sym, &putted);
  53 }
  54
  55 static int return_count = 0;
  56 static void match_return(struct expression *ret_value)
  57 {
  58         struct state_list *slist;
  59         struct sm_state *tmp;
  60         struct tracker *tracker;
  61
  62         if (!return_count) {
  63                 slist = get_all_states(my_id);
  64                 FOR_EACH_PTR(slist, tmp) {
  65                         if (tmp->state == &putted)
  66                                 add_tracker(&putted_args, my_id, tmp->name,
  67                                             tmp->sym);
  68                 } END_FOR_EACH_PTR(tmp);
  69                 free_slist(&slist);
  70         } else {
  71                 FOR_EACH_PTR(putted_args, tracker) {
  72                         tmp = get_sm_state(my_id, tracker->name, tracker->sym);
  73                         if (tmp && tmp->state != &putted)
  74                                 del_tracker(&putted_args, my_id, tracker->name,
  75                                             tracker->sym);
  76                 } END_FOR_EACH_PTR(tracker);
  77
  78         }
  79 }
  80
  81 static void print_arg(struct symbol *sym)
  82 {
  83         struct symbol *arg;
  84         int i = 0;
  85
  86         FOR_EACH_PTR(this_func->ctype.base_type->arguments, arg) {
  87                 if (sym == arg) {
  88                         sm_printf("info: puts_arg %s %d\n", get_function(), i);
  89                         return;
  90                 }
  91                 i++;
  92         } END_FOR_EACH_PTR(arg);
  93 }
  94
  95 static void match_end_func(struct symbol *sym)
  96 {
  97         struct tracker *tracker;
  98
  99         if (is_reachable())
 100                 match_return(NULL);
 101
 102         FOR_EACH_PTR(putted_args, tracker) {
 103                 print_arg(tracker->sym);
 104         } END_FOR_EACH_PTR(tracker);
 105
 106         free_trackers_and_list(&putted_args);
 107         return_count = 0;
 108 }
 109
 110 void check_puts_argument(int id)
 111 {
 112         if (!option_spammy || option_project != PROJ_KERNEL)
 113                 return;
 114
 115         my_id = id;
 116         add_hook(&match_function_def, FUNC_DEF_HOOK);
 117         add_function_hook("kobject_put", &match_put, NULL);
 118         add_function_hook("kref_put", &match_put, NULL);
 119         add_hook(&match_return, RETURN_HOOK);
 120         add_hook(&match_end_func, END_FUNC_HOOK);
 121 }