tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */
3#define _GNU_SOURCE
4#include <sys/stat.h>
5#include <sys/types.h>
6#include <unistd.h>
7#include <sys/syscall.h>
8#include <sched.h>
9#include <sys/wait.h>
10#include <sys/mount.h>
11#include "test_progs.h"
12
13#define CHECK_NEWNS(condition, tag, format...) ({ \
14 int __ret = !!(condition); \
15 if (__ret) { \
16 printf("%s:FAIL:%s ", __func__, tag); \
17 printf(format); \
18 } else { \
19 printf("%s:PASS:%s\n", __func__, tag); \
20 } \
21 __ret; \
22})
23
24struct bss {
25 __u64 dev;
26 __u64 ino;
27 __u64 pid_tgid;
28 __u64 user_pid_tgid;
29};
30
31int main(int argc, char **argv)
32{
33 pid_t pid;
34 int exit_code = 1;
35 struct stat st;
36
37 printf("Testing bpf_get_ns_current_pid_tgid helper in new ns\n");
38
39 if (stat("/proc/self/ns/pid", &st)) {
40 perror("stat failed on /proc/self/ns/pid ns\n");
41 printf("%s:FAILED\n", argv[0]);
42 return exit_code;
43 }
44
45 if (CHECK_NEWNS(unshare(CLONE_NEWPID | CLONE_NEWNS),
46 "unshare CLONE_NEWPID | CLONE_NEWNS", "error errno=%d\n", errno))
47 return exit_code;
48
49 pid = fork();
50 if (pid == -1) {
51 perror("Fork() failed\n");
52 printf("%s:FAILED\n", argv[0]);
53 return exit_code;
54 }
55
56 if (pid > 0) {
57 int status;
58
59 usleep(5);
60 waitpid(pid, &status, 0);
61 return 0;
62 } else {
63
64 pid = fork();
65 if (pid == -1) {
66 perror("Fork() failed\n");
67 printf("%s:FAILED\n", argv[0]);
68 return exit_code;
69 }
70
71 if (pid > 0) {
72 int status;
73 waitpid(pid, &status, 0);
74 return 0;
75 } else {
76 if (CHECK_NEWNS(mount("none", "/proc", NULL, MS_PRIVATE|MS_REC, NULL),
77 "Unmounting proc", "Cannot umount proc! errno=%d\n", errno))
78 return exit_code;
79
80 if (CHECK_NEWNS(mount("proc", "/proc", "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL),
81 "Mounting proc", "Cannot mount proc! errno=%d\n", errno))
82 return exit_code;
83
84 const char *probe_name = "raw_tracepoint/sys_enter";
85 const char *file = "test_ns_current_pid_tgid.o";
86 struct bpf_link *link = NULL;
87 struct bpf_program *prog;
88 struct bpf_map *bss_map;
89 struct bpf_object *obj;
90 int exit_code = 1;
91 int err, key = 0;
92 struct bss bss;
93 struct stat st;
94 __u64 id;
95
96 obj = bpf_object__open_file(file, NULL);
97 if (CHECK_NEWNS(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj)))
98 return exit_code;
99
100 err = bpf_object__load(obj);
101 if (CHECK_NEWNS(err, "obj_load", "err %d errno %d\n", err, errno))
102 goto cleanup;
103
104 bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss");
105 if (CHECK_NEWNS(!bss_map, "find_bss_map", "failed\n"))
106 goto cleanup;
107
108 prog = bpf_object__find_program_by_title(obj, probe_name);
109 if (CHECK_NEWNS(!prog, "find_prog", "prog '%s' not found\n",
110 probe_name))
111 goto cleanup;
112
113 memset(&bss, 0, sizeof(bss));
114 pid_t tid = syscall(SYS_gettid);
115 pid_t pid = getpid();
116
117 id = (__u64) tid << 32 | pid;
118 bss.user_pid_tgid = id;
119
120 if (CHECK_NEWNS(stat("/proc/self/ns/pid", &st),
121 "stat new ns", "Failed to stat /proc/self/ns/pid errno=%d\n", errno))
122 goto cleanup;
123
124 bss.dev = st.st_dev;
125 bss.ino = st.st_ino;
126
127 err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0);
128 if (CHECK_NEWNS(err, "setting_bss", "failed to set bss : %d\n", err))
129 goto cleanup;
130
131 link = bpf_program__attach_raw_tracepoint(prog, "sys_enter");
132 if (CHECK_NEWNS(IS_ERR(link), "attach_raw_tp", "err %ld\n",
133 PTR_ERR(link))) {
134 link = NULL;
135 goto cleanup;
136 }
137
138 /* trigger some syscalls */
139 usleep(1);
140
141 err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss);
142 if (CHECK_NEWNS(err, "set_bss", "failed to get bss : %d\n", err))
143 goto cleanup;
144
145 if (CHECK_NEWNS(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid",
146 "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid))
147 goto cleanup;
148
149 exit_code = 0;
150 printf("%s:PASS\n", argv[0]);
151cleanup:
152 if (!link) {
153 bpf_link__destroy(link);
154 link = NULL;
155 }
156 bpf_object__close(obj);
157 }
158 }
159}