1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * KUnit function redirection (static stubbing
4 *
5 * Copyright (C) 2022, Google LLC.
6 * Author: David Gow <davidgow@google.com>
7 */
8
9 #include <kunit/test.h>
10 #include <kunit/static_stub.h>
11 #include "hooks-impl.h"
12
13
14 /* Context for a static stub. This is stored i
15 struct kunit_static_stub_ctx {
16 void *real_fn_addr;
17 void *replacement_addr;
18 };
19
20 static void __kunit_static_stub_resource_free(
21 {
22 kfree(res->data);
23 }
24
25 /* Matching function for kunit_find_resource()
26 static bool __kunit_static_stub_resource_match
27
28
29 {
30 /* This pointer is only valid if res i
31 struct kunit_static_stub_ctx *ctx = re
32
33 /* Make sure the resource is a static
34 if (res->free != &__kunit_static_stub_
35 return false;
36
37 return ctx->real_fn_addr == match_real
38 }
39
40 /* Hook to return the address of the replaceme
41 void *__kunit_get_static_stub_address_impl(str
42 {
43 struct kunit_resource *res;
44 struct kunit_static_stub_ctx *ctx;
45 void *replacement_addr;
46
47 res = kunit_find_resource(test,
48 __kunit_stat
49 real_fn_addr
50
51 if (!res)
52 return NULL;
53
54 ctx = res->data;
55 replacement_addr = ctx->replacement_ad
56 kunit_put_resource(res);
57 return replacement_addr;
58 }
59
60 void kunit_deactivate_static_stub(struct kunit
61 {
62 struct kunit_resource *res;
63
64 KUNIT_ASSERT_PTR_NE_MSG(test, real_fn_
65 "Tried to deac
66
67 /* Look up the existing stub for this
68 res = kunit_find_resource(test,
69 __kunit_stat
70 real_fn_addr
71
72 /* Error out if the stub doesn't exist
73 KUNIT_ASSERT_PTR_NE_MSG(test, res, NUL
74 "Tried to deac
75
76 /* Free the stub. We 'put' twice, as w
77 * from kunit_find_resource()
78 */
79 kunit_remove_resource(test, res);
80 kunit_put_resource(res);
81 }
82 EXPORT_SYMBOL_GPL(kunit_deactivate_static_stub
83
84 /* Helper function for kunit_activate_static_s
85 * typechecking, so use it instead.
86 */
87 void __kunit_activate_static_stub(struct kunit
88 void *real_f
89 void *replac
90 {
91 struct kunit_static_stub_ctx *ctx;
92 struct kunit_resource *res;
93
94 KUNIT_ASSERT_PTR_NE_MSG(test, real_fn_
95 "Tried to acti
96
97 /* If the replacement address is NULL,
98 if (!replacement_addr) {
99 kunit_deactivate_static_stub(t
100 return;
101 }
102
103 /* Look up any existing stubs for this
104 res = kunit_find_resource(test,
105 __kunit_stat
106 real_fn_addr
107 if (res) {
108 ctx = res->data;
109 ctx->replacement_addr = replac
110
111 /* We got an extra reference f
112 kunit_put_resource(res);
113 } else {
114 ctx = kmalloc(sizeof(*ctx), GF
115 KUNIT_ASSERT_NOT_ERR_OR_NULL(t
116 ctx->real_fn_addr = real_fn_ad
117 ctx->replacement_addr = replac
118 res = kunit_alloc_resource(tes
119 &__kunit_
120 GFP_KERNE
121 }
122 }
123 EXPORT_SYMBOL_GPL(__kunit_activate_static_stub
124
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