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
cb1(void * map,void * key,void * value,void * ctx)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")
underflow_prog(void * ctx)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 return 0;
37 }
38
cb2(void * map,void * key,void * value,void * ctx)39 static __always_inline int cb2(void *map, void *key, void *value, void *ctx)
40 {
41 unsigned long sl = 0;
42
43 *(void **)ctx = bpf_kfunc_call_test_acquire(&sl);
44 /* Without the fix this would leak memory */
45 return 0;
46 }
47
48 SEC("?tc")
leak_prog(void * ctx)49 int leak_prog(void *ctx)
50 {
51 struct prog_test_ref_kfunc *p;
52 struct map_value *v;
53
54 v = bpf_map_lookup_elem(&array_map, &(int){0});
55 if (!v)
56 return 0;
57
58 p = NULL;
59 bpf_for_each_map_elem(&array_map, cb2, &p, 0);
60 p = bpf_kptr_xchg(&v->ptr, p);
61 if (p)
62 bpf_kfunc_call_test_release(p);
63 return 0;
64 }
65
cb(void * map,void * key,void * value,void * ctx)66 static __always_inline int cb(void *map, void *key, void *value, void *ctx)
67 {
68 return 0;
69 }
70
cb3(void * map,void * key,void * value,void * ctx)71 static __always_inline int cb3(void *map, void *key, void *value, void *ctx)
72 {
73 unsigned long sl = 0;
74 void *p;
75
76 bpf_kfunc_call_test_acquire(&sl);
77 bpf_for_each_map_elem(&array_map, cb, &p, 0);
78 /* It should only complain here, not in cb. This is why we need
79 * callback_ref to be set to frameno.
80 */
81 return 0;
82 }
83
84 SEC("?tc")
nested_cb(void * ctx)85 int nested_cb(void *ctx)
86 {
87 struct prog_test_ref_kfunc *p;
88 unsigned long sl = 0;
89 int sp = 0;
90
91 p = bpf_kfunc_call_test_acquire(&sl);
92 if (!p)
93 return 0;
94 bpf_for_each_map_elem(&array_map, cb3, &sp, 0);
95 bpf_kfunc_call_test_release(p);
96 return 0;
97 }
98
99 SEC("?tc")
non_cb_transfer_ref(void * ctx)100 int non_cb_transfer_ref(void *ctx)
101 {
102 struct prog_test_ref_kfunc *p;
103 unsigned long sl = 0;
104
105 p = bpf_kfunc_call_test_acquire(&sl);
106 if (!p)
107 return 0;
108 cb1(NULL, NULL, NULL, &p);
109 bpf_kfunc_call_test_acquire(&sl);
110 return 0;
111 }
112
113 char _license[] SEC("license") = "GPL";
114