1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */ 3 #include <test_progs.h> 4 #include <sys/stat.h> 5 #include <sys/types.h> 6 #include <unistd.h> 7 #include <sys/syscall.h> 8 9 struct bss { 10 __u64 dev; 11 __u64 ino; 12 __u64 pid_tgid; 13 __u64 user_pid_tgid; 14 }; 15 16 void test_ns_current_pid_tgid(void) 17 { 18 const char *probe_name = "raw_tracepoint/sys_enter"; 19 const char *file = "test_ns_current_pid_tgid.o"; 20 int err, key = 0, duration = 0; 21 struct bpf_link *link = NULL; 22 struct bpf_program *prog; 23 struct bpf_map *bss_map; 24 struct bpf_object *obj; 25 struct bss bss; 26 struct stat st; 27 __u64 id; 28 29 obj = bpf_object__open_file(file, NULL); 30 if (CHECK(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj))) 31 return; 32 33 err = bpf_object__load(obj); 34 if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) 35 goto cleanup; 36 37 bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss"); 38 if (CHECK(!bss_map, "find_bss_map", "failed\n")) 39 goto cleanup; 40 41 prog = bpf_object__find_program_by_title(obj, probe_name); 42 if (CHECK(!prog, "find_prog", "prog '%s' not found\n", 43 probe_name)) 44 goto cleanup; 45 46 memset(&bss, 0, sizeof(bss)); 47 pid_t tid = syscall(SYS_gettid); 48 pid_t pid = getpid(); 49 50 id = (__u64) tid << 32 | pid; 51 bss.user_pid_tgid = id; 52 53 if (CHECK_FAIL(stat("/proc/self/ns/pid", &st))) { 54 perror("Failed to stat /proc/self/ns/pid"); 55 goto cleanup; 56 } 57 58 bss.dev = st.st_dev; 59 bss.ino = st.st_ino; 60 61 err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0); 62 if (CHECK(err, "setting_bss", "failed to set bss : %d\n", err)) 63 goto cleanup; 64 65 link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); 66 if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", 67 PTR_ERR(link))) { 68 link = NULL; 69 goto cleanup; 70 } 71 72 /* trigger some syscalls */ 73 usleep(1); 74 75 err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss); 76 if (CHECK(err, "set_bss", "failed to get bss : %d\n", err)) 77 goto cleanup; 78 79 if (CHECK(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid", 80 "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid)) 81 goto cleanup; 82 cleanup: 83 bpf_link__destroy(link); 84 bpf_object__close(obj); 85 } 86