2 * sparse/check_memory.c
4 * Copyright (C) 2008 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
12 #include "smatch_slist.h"
22 static void match_assign(struct expression
*expr
)
24 struct expression
*left
, *right
;
25 char *left_name
, *right_name
;
26 struct symbol
*left_sym
, *right_sym
;
27 struct smatch_state
*state
;
29 left
= strip_expr(expr
->left
);
30 left_name
= get_variable_from_expr(left
, &left_sym
);
34 free_string(left_name
);
38 right
= strip_expr(expr
->right
);
41 if (right
->type
== EXPR_CALL
)
42 right_name
= get_variable_from_expr(expr
->fn
, NULL
);
43 if (right_name
&& !strcmp(right_name
, "kmalloc")) {
44 if (left_sym
->ctype
.modifiers
& (MOD_NONLOCAL
| MOD_STATIC
| MOD_ADDRESSABLE
))
46 set_state(left_name
, my_id
, left_sym
, &allocated
);
47 free_string(right_name
);
50 free_string(right_name
);
52 right_name
= get_variable_from_expr(right
, &right_sym
);
53 if (right_name
&& (state
= get_state(right_name
, my_id
, right_sym
))) {
55 smatch_msg("assigning freed pointer");
56 set_state(right_name
, my_id
, right_sym
, &assigned
);
57 free_string(right_name
);
60 free_string(right_name
);
65 if (get_state(left_name
, my_id
, left_sym
) == &isfree
) {
66 set_state(left_name
, my_id
, left_sym
, &unfree
);
70 static int is_null(char *name
, struct symbol
*sym
)
72 struct smatch_state
*state
;
75 * FIXME. Ha ha ha... This is so wrong.
76 * I'm pulling in data from the check_null_deref script.
77 * I just happen to know that its ID is 3.
78 * The correct approved way to do this is to get the data from
79 * smatch_extra. But right now smatch_extra doesn't track it.
81 state
= get_state(name
, 3, sym
);
82 if (state
&& !strcmp(state
->name
, "isnull"))
87 static void match_kfree(struct expression
*expr
)
89 struct expression
*ptr_expr
;
90 struct state_list
*slist
;
93 struct symbol
*ptr_sym
;
96 fn_name
= get_variable_from_expr(expr
->fn
, NULL
);
98 if (!fn_name
|| strcmp(fn_name
, "kfree"))
101 ptr_expr
= get_argument_from_call_expr(expr
->args
, 0);
102 ptr_name
= get_variable_from_expr(ptr_expr
, &ptr_sym
);
103 slist
= get_possible_states(ptr_name
, my_id
, ptr_sym
);
104 if (slist_has_state(slist
, &isfree
) && !is_null(ptr_name
, ptr_sym
)) {
105 smatch_msg("double free of %s", ptr_name
);
107 set_state(ptr_name
, my_id
, ptr_sym
, &isfree
);
109 free_string(fn_name
);
112 static int possibly_allocated(struct state_list
*slist
)
114 struct sm_state
*tmp
;
116 FOR_EACH_PTR(slist
, tmp
) {
117 if (tmp
->state
== &allocated
)
119 } END_FOR_EACH_PTR(tmp
);
123 static void check_for_allocated()
125 struct state_list
*slist
;
126 struct sm_state
*tmp
;
128 slist
= get_all_states(my_id
);
129 FOR_EACH_PTR(slist
, tmp
) {
130 if (possibly_allocated(tmp
->possible
) &&
131 !is_null(tmp
->name
, tmp
->sym
))
132 smatch_msg("possible memery leak of %s", tmp
->name
);
133 } END_FOR_EACH_PTR(tmp
);
137 static void match_return(struct statement
*stmt
)
141 struct smatch_state
*state
;
143 name
= get_variable_from_expr(stmt
->ret_value
, &sym
);
144 if ((state
= get_state(name
, my_id
, sym
))) {
145 set_state(name
, my_id
, sym
, &returned
);
148 check_for_allocated();
151 static void match_end_func(struct symbol
*sym
)
153 check_for_allocated();
156 void register_memory(int id
)
159 add_hook(&match_kfree
, FUNCTION_CALL_HOOK
);
160 add_hook(&match_assign
, ASSIGNMENT_HOOK
);
161 add_hook(&match_return
, RETURN_HOOK
);
162 add_hook(&match_end_func
, END_FUNC_HOOK
);