1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <vmlinux.h> |
3 | #include <bpf/bpf_helpers.h> |
4 | |
5 | #include "bpf_misc.h" |
6 | |
7 | struct hmap_elem { |
8 | struct bpf_timer timer; |
9 | }; |
10 | |
11 | struct { |
12 | __uint(type, BPF_MAP_TYPE_HASH); |
13 | __uint(max_entries, 64); |
14 | __type(key, int); |
15 | __type(value, struct hmap_elem); |
16 | } hmap SEC(".maps" ); |
17 | |
18 | __attribute__((noinline)) |
19 | static int timer_cb(void *map, int *key, struct bpf_timer *timer) |
20 | { |
21 | volatile char buf[256] = {}; |
22 | return buf[69]; |
23 | } |
24 | |
25 | __attribute__((noinline)) |
26 | static int bad_timer_cb(void *map, int *key, struct bpf_timer *timer) |
27 | { |
28 | volatile char buf[300] = {}; |
29 | return buf[255] + timer_cb(map: NULL, key: NULL, timer: NULL); |
30 | } |
31 | |
32 | SEC("tc" ) |
33 | __failure __msg("combined stack size of 2 calls is" ) |
34 | int pseudo_call_check(struct __sk_buff *ctx) |
35 | { |
36 | struct hmap_elem *elem; |
37 | volatile char buf[256] = {}; |
38 | |
39 | elem = bpf_map_lookup_elem(&hmap, &(int){0}); |
40 | if (!elem) |
41 | return 0; |
42 | |
43 | timer_cb(NULL, NULL, NULL); |
44 | return bpf_timer_set_callback(&elem->timer, timer_cb) + buf[0]; |
45 | } |
46 | |
47 | SEC("tc" ) |
48 | __failure __msg("combined stack size of 2 calls is" ) |
49 | int async_call_root_check(struct __sk_buff *ctx) |
50 | { |
51 | struct hmap_elem *elem; |
52 | volatile char buf[256] = {}; |
53 | |
54 | elem = bpf_map_lookup_elem(&hmap, &(int){0}); |
55 | if (!elem) |
56 | return 0; |
57 | |
58 | return bpf_timer_set_callback(&elem->timer, bad_timer_cb) + buf[0]; |
59 | } |
60 | |
61 | char _license[] SEC("license" ) = "GPL" ; |
62 | |