Self tests added for new helper Signed-off-by: Carlos Neira <cneirabustos@xxxxxxxxx> --- tools/testing/selftests/bpf/bpf_helpers.h | 3 + .../bpf/prog_tests/get_ns_current_pid_tgid.c | 85 +++++++++++++++++++ .../bpf/progs/get_ns_current_pid_tgid_kern.c | 47 ++++++++++ 3 files changed, 135 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/get_ns_current_pid_tgid.c create mode 100644 tools/testing/selftests/bpf/progs/get_ns_current_pid_tgid_kern.c diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 54a50699bbfd..19c03ba066b1 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -233,6 +233,9 @@ static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal; static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip, int ip_len, void *tcp, int tcp_len) = (void *) BPF_FUNC_tcp_gen_syncookie; +static unsigned long long (*bpf_get_ns_current_pid_tgid)(__u64 dev, __u64 inum) = + (void *) BPF_FUNC_get_ns_current_pid_tgid; + /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions diff --git a/tools/testing/selftests/bpf/prog_tests/get_ns_current_pid_tgid.c b/tools/testing/selftests/bpf/prog_tests/get_ns_current_pid_tgid.c new file mode 100644 index 000000000000..4d8ec524d373 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/get_ns_current_pid_tgid.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Carlos Neira cneirabustos@xxxxxxxxx */ +#include <test_progs.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <sys/syscall.h> + +void test_get_ns_current_pid_tgid(void) +{ + const char *probe_name = "syscalls/sys_enter_nanosleep"; + const char *file = "get_ns_current_pid_tgid_kern.o"; + int ns_data_map_fd, duration = 0; + struct perf_event_attr attr = {}; + int err, efd, prog_fd, pmu_fd; + __u64 ino, dev, id, nspid; + struct bpf_object *obj; + struct stat st; + __u32 key = 0; + char buf[256]; + + err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); + if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) + return; + + ns_data_map_fd = bpf_find_map(__func__, obj, "ns_data_map"); + if (CHECK_FAIL(ns_data_map_fd < 0)) + goto close_prog; + + pid_t tid = syscall(SYS_gettid); + pid_t pid = getpid(); + + id = (__u64) tid << 32 | pid; + bpf_map_update_elem(ns_data_map_fd, &key, &id, 0); + + if (stat("/proc/self/ns/pid", &st)) + goto close_prog; + + dev = st.st_dev; + ino = st.st_ino; + key = 1; + bpf_map_update_elem(ns_data_map_fd, &key, &dev, 0); + key = 2; + bpf_map_update_elem(ns_data_map_fd, &key, &ino, 0); + + snprintf(buf, sizeof(buf), + "/sys/kernel/debug/tracing/events/%s/id", probe_name); + efd = open(buf, O_RDONLY, 0); + read(efd, buf, sizeof(buf)); + close(efd); + attr.config = strtol(buf, NULL, 0); + attr.type = PERF_TYPE_TRACEPOINT; + attr.sample_type = PERF_SAMPLE_RAW; + attr.sample_period = 1; + attr.wakeup_events = 1; + + pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); + if (CHECK_FAIL(pmu_fd < 0)) + goto cleanup; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); + if (CHECK_FAIL(err)) + goto cleanup; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); + if (CHECK_FAIL(err)) + goto cleanup; + + /* trigger some syscalls */ + sleep(1); + key = 3; + err = bpf_map_lookup_elem(ns_data_map_fd, &key, &nspid); + if (CHECK_FAIL(err)) + goto cleanup; + + if (CHECK(id != nspid, "Compare user pid/tgid %llu vs. bpf pid/tgid %llu", + "Userspace pid/tgid %llu EBPF pid/tgid %llu\n", id, nspid)) + goto cleanup; + +cleanup: + close(pmu_fd); +close_prog: + bpf_object__close(obj); +} diff --git a/tools/testing/selftests/bpf/progs/get_ns_current_pid_tgid_kern.c b/tools/testing/selftests/bpf/progs/get_ns_current_pid_tgid_kern.c new file mode 100644 index 000000000000..00a325e85e8c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/get_ns_current_pid_tgid_kern.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Carlos Neira cneirabustos@xxxxxxxxx */ + +#include <linux/bpf.h> +#include "bpf_helpers.h" + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 4); + __type(key, __u32); + __type(value, __u64); +} ns_data_map SEC(".maps"); + + +SEC("tracepoint/syscalls/sys_enter_nanosleep") +int trace(void *ctx) +{ + __u64 *val, *inum, *dev, nspid, *expected_pid; + __u32 key = 1; + + dev = bpf_map_lookup_elem(&ns_data_map, &key); + if (!dev) + return 0; + key = 2; + inum = bpf_map_lookup_elem(&ns_data_map, &key); + + if (!inum) + return 0; + + nspid = bpf_get_ns_current_pid_tgid(*dev, *inum); + key = 0; + expected_pid = bpf_map_lookup_elem(&ns_data_map, &key); + + if (!expected_pid || *expected_pid != nspid) + return 0; + + key = 3; + val = bpf_map_lookup_elem(&ns_data_map, &key); + + if (val) + *val = nspid; + + return 0; +} + +char _license[] SEC("license") = "GPL"; +__u32 _version SEC("version") = 1; -- 2.20.1