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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
5bacd780 | 2 | #include <stdio.h> |
bc1a8597 | 3 | #include <stdlib.h> |
5bacd780 AS |
4 | #include <unistd.h> |
5 | #include <linux/filter.h> | |
6 | #include <linux/seccomp.h> | |
7 | #include <sys/prctl.h> | |
2bf3e2ef | 8 | #include <bpf/bpf.h> |
bc1a8597 | 9 | #include <bpf/libbpf.h> |
973d94d8 | 10 | #include <sys/resource.h> |
24a6034a | 11 | #include "trace_helpers.h" |
5bacd780 | 12 | |
bc1a8597 DL |
13 | #ifdef __mips__ |
14 | #define MAX_ENTRIES 6000 /* MIPS n64 syscalls start at 5000 */ | |
15 | #else | |
16 | #define MAX_ENTRIES 1024 | |
17 | #endif | |
18 | ||
5bacd780 AS |
19 | /* install fake seccomp program to enable seccomp code path inside the kernel, |
20 | * so that our kprobe attached to seccomp_phase1() can be triggered | |
21 | */ | |
22 | static void install_accept_all_seccomp(void) | |
23 | { | |
24 | struct sock_filter filter[] = { | |
25 | BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), | |
26 | }; | |
27 | struct sock_fprog prog = { | |
28 | .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])), | |
29 | .filter = filter, | |
30 | }; | |
31 | if (prctl(PR_SET_SECCOMP, 2, &prog)) | |
32 | perror("prctl"); | |
33 | } | |
34 | ||
35 | int main(int ac, char **argv) | |
36 | { | |
bc1a8597 DL |
37 | struct bpf_link *link = NULL; |
38 | struct bpf_program *prog; | |
39 | struct bpf_object *obj; | |
40 | int key, fd, progs_fd; | |
698584df | 41 | const char *section; |
bc1a8597 | 42 | char filename[256]; |
bc1a8597 | 43 | FILE *f; |
5bacd780 | 44 | |
bc1a8597 DL |
45 | snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); |
46 | obj = bpf_object__open_file(filename, NULL); | |
47 | if (libbpf_get_error(obj)) { | |
48 | fprintf(stderr, "ERROR: opening BPF object file failed\n"); | |
49 | return 0; | |
50 | } | |
51 | ||
52 | prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); | |
53 | if (!prog) { | |
54 | printf("finding a prog in obj file failed\n"); | |
55 | goto cleanup; | |
56 | } | |
57 | ||
58 | /* load BPF program */ | |
59 | if (bpf_object__load(obj)) { | |
60 | fprintf(stderr, "ERROR: loading BPF object file failed\n"); | |
61 | goto cleanup; | |
62 | } | |
63 | ||
64 | link = bpf_program__attach(prog); | |
65 | if (libbpf_get_error(link)) { | |
66 | fprintf(stderr, "ERROR: bpf_program__attach failed\n"); | |
67 | link = NULL; | |
68 | goto cleanup; | |
69 | } | |
70 | ||
71 | progs_fd = bpf_object__find_map_fd_by_name(obj, "progs"); | |
72 | if (progs_fd < 0) { | |
73 | fprintf(stderr, "ERROR: finding a map in obj file failed\n"); | |
74 | goto cleanup; | |
75 | } | |
76 | ||
77 | bpf_object__for_each_program(prog, obj) { | |
698584df | 78 | section = bpf_program__section_name(prog); |
bc1a8597 | 79 | /* register only syscalls to PROG_ARRAY */ |
698584df | 80 | if (sscanf(section, "kprobe/%d", &key) != 1) |
bc1a8597 DL |
81 | continue; |
82 | ||
83 | fd = bpf_program__fd(prog); | |
84 | bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY); | |
5bacd780 AS |
85 | } |
86 | ||
87 | install_accept_all_seccomp(); | |
88 | ||
89 | f = popen("dd if=/dev/zero of=/dev/null count=5", "r"); | |
90 | (void) f; | |
91 | ||
92 | read_trace_pipe(); | |
93 | ||
bc1a8597 DL |
94 | cleanup: |
95 | bpf_link__destroy(link); | |
96 | bpf_object__close(obj); | |
5bacd780 AS |
97 | return 0; |
98 | } |