1 // SPDX-License-Identifier: GPL-2.0
2 #include <vmlinux.h>
3 #include <bpf/bpf_tracing.h>
4 #include <bpf/bpf_helpers.h>
5 #include "../bpf_testmod/bpf_testmod_kfunc.h"
6
7 struct map_value {
8 struct prog_test_ref_kfunc __kptr *ptr;
9 };
10
11 struct {
12 __uint(type, BPF_MAP_TYPE_ARRAY);
13 __type(key, int);
14 __type(value, struct map_value);
15 __uint(max_entries, 16);
16 } array_map SEC(".maps");
17
18 static __noinline int cb1(void *map, void *key, void *value, void *ctx)
19 {
20 void *p = *(void **)ctx;
21 bpf_kfunc_call_test_release(p);
22 /* Without the fix this would cause underflow */
23 return 0;
24 }
25
26 SEC("?tc")
27 int underflow_prog(void *ctx)
28 {
29 struct prog_test_ref_kfunc *p;
30 unsigned long sl = 0;
31
32 p = bpf_kfunc_call_test_acquire(&sl);
33 if (!p)
34 return 0;
35 bpf_for_each_map_elem(&array_map, cb1, &p, 0);
36 bpf_kfunc_call_test_release(p);
37 return 0;
38 }
39
40 static __always_inline int cb2(void *map, void *key, void *value, void *ctx)
41 {
42 unsigned long sl = 0;
43
44 *(void **)ctx = bpf_kfunc_call_test_acquire(&sl);
45 /* Without the fix this would leak memory */
46 return 0;
47 }
48
49 SEC("?tc")
50 int leak_prog(void *ctx)
51 {
52 struct prog_test_ref_kfunc *p;
53 struct map_value *v;
54
55 v = bpf_map_lookup_elem(&array_map, &(int){0});
56 if (!v)
57 return 0;
58
59 p = NULL;
60 bpf_for_each_map_elem(&array_map, cb2, &p, 0);
61 p = bpf_kptr_xchg(&v->ptr, p);
62 if (p)
63 bpf_kfunc_call_test_release(p);
64 return 0;
65 }
66
67 static __always_inline int cb(void *map, void *key, void *value, void *ctx)
68 {
69 return 0;
70 }
71
72 static __always_inline int cb3(void *map, void *key, void *value, void *ctx)
73 {
74 unsigned long sl = 0;
75 void *p;
76
77 bpf_kfunc_call_test_acquire(&sl);
78 bpf_for_each_map_elem(&array_map, cb, &p, 0);
79 /* It should only complain here, not in cb. This is why we need
80 * callback_ref to be set to frameno.
81 */
82 return 0;
83 }
84
85 SEC("?tc")
86 int nested_cb(void *ctx)
87 {
88 struct prog_test_ref_kfunc *p;
89 unsigned long sl = 0;
90 int sp = 0;
91
92 p = bpf_kfunc_call_test_acquire(&sl);
93 if (!p)
94 return 0;
95 bpf_for_each_map_elem(&array_map, cb3, &sp, 0);
96 bpf_kfunc_call_test_release(p);
97 return 0;
98 }
99
100 SEC("?tc")
101 int non_cb_transfer_ref(void *ctx)
102 {
103 struct prog_test_ref_kfunc *p;
104 unsigned long sl = 0;
105
106 p = bpf_kfunc_call_test_acquire(&sl);
107 if (!p)
108 return 0;
109 cb1(NULL, NULL, NULL, &p);
110 bpf_kfunc_call_test_acquire(&sl);
111 return 0;
112 }
113
114 char _license[] SEC("license") = "GPL";
115
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