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 const char *allocation_funcs
[] = {
28 static int is_allocation(struct expression
*expr
)
33 if (expr
->type
!= EXPR_CALL
)
36 if (!(fn_name
= get_variable_from_expr(expr
->fn
, NULL
)))
39 for (i
= 0; allocation_funcs
[i
]; i
++) {
40 if (!strcmp(fn_name
, allocation_funcs
[i
])) {
49 static void match_assign(struct expression
*expr
)
51 struct expression
*left
, *right
;
52 char *left_name
, *right_name
;
53 struct symbol
*left_sym
, *right_sym
;
54 struct smatch_state
*state
;
56 left
= strip_expr(expr
->left
);
57 left_name
= get_variable_from_expr(left
, &left_sym
);
61 free_string(left_name
);
65 right
= strip_expr(expr
->right
);
66 if (is_allocation(right
)) {
67 if (left_sym
->ctype
.modifiers
& (MOD_NONLOCAL
| MOD_STATIC
| MOD_ADDRESSABLE
))
69 set_state(left_name
, my_id
, left_sym
, &allocated
);
73 right_name
= get_variable_from_expr(right
, &right_sym
);
74 if (right_name
&& (state
= get_state(right_name
, my_id
, right_sym
))) {
76 smatch_msg("assigning freed pointer");
77 set_state(right_name
, my_id
, right_sym
, &assigned
);
78 free_string(right_name
);
81 free_string(right_name
);
86 if (get_state(left_name
, my_id
, left_sym
) == &isfree
) {
87 set_state(left_name
, my_id
, left_sym
, &unfree
);
91 static int is_null(char *name
, struct symbol
*sym
)
93 struct smatch_state
*state
;
96 * FIXME. Ha ha ha... This is so wrong.
97 * I'm pulling in data from the check_null_deref script.
98 * I just happen to know that its ID is 3.
99 * The correct approved way to do this is to get the data from
100 * smatch_extra. But right now smatch_extra doesn't track it.
102 state
= get_state(name
, 3, sym
);
103 if (state
&& !strcmp(state
->name
, "isnull"))
108 static void match_kfree(struct expression
*expr
)
110 struct expression
*ptr_expr
;
111 struct state_list
*slist
;
114 struct symbol
*ptr_sym
;
117 fn_name
= get_variable_from_expr(expr
->fn
, NULL
);
119 if (!fn_name
|| strcmp(fn_name
, "kfree"))
122 ptr_expr
= get_argument_from_call_expr(expr
->args
, 0);
123 ptr_name
= get_variable_from_expr(ptr_expr
, &ptr_sym
);
124 slist
= get_possible_states(ptr_name
, my_id
, ptr_sym
);
125 if (slist_has_state(slist
, &isfree
) && !is_null(ptr_name
, ptr_sym
)) {
126 smatch_msg("double free of %s", ptr_name
);
128 set_state(ptr_name
, my_id
, ptr_sym
, &isfree
);
130 free_string(fn_name
);
133 static int possibly_allocated(struct state_list
*slist
)
135 struct sm_state
*tmp
;
137 FOR_EACH_PTR(slist
, tmp
) {
138 if (tmp
->state
== &allocated
)
140 } END_FOR_EACH_PTR(tmp
);
144 static void check_for_allocated()
146 struct state_list
*slist
;
147 struct sm_state
*tmp
;
149 slist
= get_all_states(my_id
);
150 FOR_EACH_PTR(slist
, tmp
) {
151 if (possibly_allocated(tmp
->possible
) &&
152 !is_null(tmp
->name
, tmp
->sym
))
153 smatch_msg("possible memery leak of %s", tmp
->name
);
154 } END_FOR_EACH_PTR(tmp
);
158 static void match_return(struct statement
*stmt
)
162 struct smatch_state
*state
;
164 name
= get_variable_from_expr(stmt
->ret_value
, &sym
);
165 if ((state
= get_state(name
, my_id
, sym
))) {
166 set_state(name
, my_id
, sym
, &returned
);
169 check_for_allocated();
172 static void match_end_func(struct symbol
*sym
)
174 check_for_allocated();
177 void register_memory(int id
)
180 add_hook(&match_kfree
, FUNCTION_CALL_HOOK
);
181 add_hook(&match_assign
, ASSIGNMENT_HOOK
);
182 add_hook(&match_return
, RETURN_HOOK
);
183 add_hook(&match_end_func
, END_FUNC_HOOK
);