2 * sparse/check_locking.c
4 * Copyright (C) 2009 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
11 * For this test let's look for functions that return a negative value
12 * with a spinlock held.
14 * One short coming is that it assumes a function isn't supposed
15 * to return negative with a lock held. Perhaps the function was
16 * called with the lock held. A more complicated script could check that.
22 #include "smatch_slist.h"
24 static const char *lock_funcs
[] = {
30 static const char *unlock_funcs
[] = {
42 * merge_func() can go away when we fix the core to just store all the possible
45 * The parameters are passed in alphabetical order with NULL at the beginning
46 * of the alphabet. (s2 is never NULL).
49 static struct smatch_state
*merge_func(const char *name
, struct symbol
*sym
,
50 struct smatch_state
*s1
,
51 struct smatch_state
*s2
)
59 static char *match_lock_func(char *fn_name
, struct expression_list
*args
)
61 struct expression
*lock_expr
;
64 for (i
= 0; lock_funcs
[i
]; i
++) {
65 if (!strcmp(fn_name
, lock_funcs
[i
])) {
66 lock_expr
= get_argument_from_call_expr(args
, 0);
67 return get_variable_from_expr(lock_expr
, NULL
);
70 if (!strcmp(fn_name
, "lock_kernel"))
75 static char *match_unlock_func(char *fn_name
, struct expression_list
*args
)
77 struct expression
*lock_expr
;
80 for (i
= 0; unlock_funcs
[i
]; i
++) {
81 if (!strcmp(fn_name
, unlock_funcs
[i
])) {
82 lock_expr
= get_argument_from_call_expr(args
, 0);
83 return get_variable_from_expr(lock_expr
, NULL
);
86 if (!strcmp(fn_name
, "unlock_kernel"))
91 static void match_call(struct expression
*expr
)
96 fn_name
= get_variable_from_expr(expr
->fn
, NULL
);
100 if ((lock_name
= match_lock_func(fn_name
, expr
->args
))) {
101 set_state(lock_name
, my_id
, NULL
, &locked
);
102 } else if ((lock_name
= match_unlock_func(fn_name
, expr
->args
))) {
103 set_state(lock_name
, my_id
, NULL
, &unlocked
);
105 free_string(fn_name
);
109 static void match_condition(struct expression
*expr
)
111 /* __raw_spin_is_locked */
114 static int possibly_negative(struct expression
*expr
)
118 struct state_list
*slist
;
119 struct sm_state
*tmp
;
121 name
= get_variable_from_expr(expr
, &sym
);
124 slist
= get_possible_states(name
, SMATCH_EXTRA
, sym
);
125 FOR_EACH_PTR(slist
, tmp
) {
128 if (tmp
->state
->data
)
129 value
= *(int *)tmp
->state
->data
;
134 } END_FOR_EACH_PTR(tmp
);
138 static void match_return(struct statement
*stmt
)
141 struct state_list
*slist
;
142 struct sm_state
*tmp
;
144 ret_val
= get_value(stmt
->ret_value
);
148 if (ret_val
== UNDEFINED
) {
149 if (!possibly_negative(stmt
->ret_value
))
153 slist
= get_all_states(my_id
);
154 FOR_EACH_PTR(slist
, tmp
) {
155 if (tmp
->state
!= &unlocked
)
156 smatch_msg("returned negative with %s lock held",
158 } END_FOR_EACH_PTR(tmp
);
161 void register_locking(int id
)
164 add_merge_hook(my_id
, &merge_func
);
165 add_hook(&match_call
, FUNCTION_CALL_HOOK
);
166 add_hook(&match_return
, RETURN_HOOK
);