db: don't turn RaiseError on
[smatch.git] / check_held_dev.c
blob2245e8d4f19fde6d2ea7a8aaa0dc10914fa1655d
1 /*
2 * sparse/check_hold_dev.c
4 * Copyright (C) 2009 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
8 */
11 * This check is supposed to find bugs in reference counting using dev_hold()
12 * and dev_put().
14 * When a device is first held, if an error happens later in the function
15 * it needs to be released on all the error paths.
19 #include "smatch.h"
20 #include "smatch_extra.h"
21 #include "smatch_slist.h"
23 static int my_id;
25 STATE(held);
26 STATE(released);
28 static void match_dev_hold(const char *fn, struct expression *expr, void *data)
30 struct expression *arg_expr;
32 arg_expr = get_argument_from_call_expr(expr->args, 0);
33 set_state_expr(my_id, arg_expr, &held);
36 static void match_dev_put(const char *fn, struct expression *expr, void *data)
38 struct expression *arg_expr;
40 arg_expr = get_argument_from_call_expr(expr->args, 0);
41 set_state_expr(my_id, arg_expr, &released);
44 static void match_returns_held(const char *fn, struct expression *call_expr,
45 struct expression *assign_expr, void *unused)
47 if (assign_expr)
48 set_state_expr(my_id, assign_expr->left, &held);
51 static void match_returns_null(const char *fn, struct expression *call_expr,
52 struct expression *assign_expr, void *unused)
54 if (assign_expr)
55 set_state_expr(my_id, assign_expr->left, &released);
58 static void check_for_held(void)
60 struct state_list *slist;
61 struct sm_state *tmp;
63 slist = get_all_states(my_id);
64 FOR_EACH_PTR(slist, tmp) {
65 if (slist_has_state(tmp->possible, &held)) {
66 sm_msg("warn: '%s' held on error path.",
67 tmp->name);
69 } END_FOR_EACH_PTR(tmp);
70 free_slist(&slist);
73 static void print_returns_held(struct expression *expr)
75 struct sm_state *sm;
77 if (!option_info)
78 return;
79 sm = get_sm_state_expr(my_id, expr);
80 if (!sm)
81 return;
82 if (slist_has_state(sm->possible, &held))
83 sm_info("returned dev is held.");
86 static void match_return(struct expression *ret_value)
88 print_returns_held(ret_value);
89 if (!is_error_return(ret_value))
90 return;
91 check_for_held();
94 static void register_returns_held_funcs(void)
96 struct token *token;
97 const char *func;
99 token = get_tokens_file("kernel.returns_held_funcs");
100 if (!token)
101 return;
102 if (token_type(token) != TOKEN_STREAMBEGIN)
103 return;
104 token = token->next;
105 while (token_type(token) != TOKEN_STREAMEND) {
106 if (token_type(token) != TOKEN_IDENT)
107 return;
108 func = show_ident(token->ident);
109 return_implies_state(func, valid_ptr_min, valid_ptr_max,
110 &match_returns_held, NULL);
111 return_implies_state(func, 0, 0, &match_returns_null,
112 NULL);
113 token = token->next;
115 clear_token_alloc();
118 void check_hold_dev(int id)
120 if (option_project != PROJ_KERNEL)
121 return;
123 my_id = id;
124 add_function_hook("dev_hold", &match_dev_hold, NULL);
125 add_function_hook("dev_put", &match_dev_put, NULL);
126 register_returns_held_funcs();
127 add_hook(&match_return, RETURN_HOOK);