diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/send_signal.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/send_signal.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c new file mode 100644 index 000000000..75b72c751 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include <sys/time.h> +#include <sys/resource.h> +#include "test_send_signal_kern.skel.h" + +static volatile int sigusr1_received = 0; + +static void sigusr1_handler(int signum) +{ + sigusr1_received++; +} + +static void test_send_signal_common(struct perf_event_attr *attr, + bool signal_thread, + const char *test_name) +{ + struct test_send_signal_kern *skel; + int pipe_c2p[2], pipe_p2c[2]; + int err = -1, pmu_fd = -1; + __u32 duration = 0; + char buf[256]; + pid_t pid; + + if (CHECK(pipe(pipe_c2p), test_name, + "pipe pipe_c2p error: %s\n", strerror(errno))) + return; + + if (CHECK(pipe(pipe_p2c), test_name, + "pipe pipe_p2c error: %s\n", strerror(errno))) { + close(pipe_c2p[0]); + close(pipe_c2p[1]); + return; + } + + pid = fork(); + if (CHECK(pid < 0, test_name, "fork error: %s\n", strerror(errno))) { + close(pipe_c2p[0]); + close(pipe_c2p[1]); + close(pipe_p2c[0]); + close(pipe_p2c[1]); + return; + } + + if (pid == 0) { + int old_prio; + + /* install signal handler and notify parent */ + signal(SIGUSR1, sigusr1_handler); + + close(pipe_c2p[0]); /* close read */ + close(pipe_p2c[1]); /* close write */ + + /* boost with a high priority so we got a higher chance + * that if an interrupt happens, the underlying task + * is this process. + */ + errno = 0; + old_prio = getpriority(PRIO_PROCESS, 0); + ASSERT_OK(errno, "getpriority"); + ASSERT_OK(setpriority(PRIO_PROCESS, 0, -20), "setpriority"); + + /* notify parent signal handler is installed */ + CHECK(write(pipe_c2p[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno); + + /* make sure parent enabled bpf program to send_signal */ + CHECK(read(pipe_p2c[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno); + + /* wait a little for signal handler */ + sleep(1); + + buf[0] = sigusr1_received ? '2' : '0'; + CHECK(write(pipe_c2p[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno); + + /* wait for parent notification and exit */ + CHECK(read(pipe_p2c[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno); + + /* restore the old priority */ + ASSERT_OK(setpriority(PRIO_PROCESS, 0, old_prio), "setpriority"); + + close(pipe_c2p[1]); + close(pipe_p2c[0]); + exit(0); + } + + close(pipe_c2p[1]); /* close write */ + close(pipe_p2c[0]); /* close read */ + + skel = test_send_signal_kern__open_and_load(); + if (CHECK(!skel, "skel_open_and_load", "skeleton open_and_load failed\n")) + goto skel_open_load_failure; + + if (!attr) { + err = test_send_signal_kern__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed\n")) { + err = -1; + goto destroy_skel; + } + } else { + pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1, + -1 /* group id */, 0 /* flags */); + if (CHECK(pmu_fd < 0, test_name, "perf_event_open error: %s\n", + strerror(errno))) { + err = -1; + goto destroy_skel; + } + + skel->links.send_signal_perf = + bpf_program__attach_perf_event(skel->progs.send_signal_perf, pmu_fd); + if (CHECK(IS_ERR(skel->links.send_signal_perf), "attach_perf_event", + "err %ld\n", PTR_ERR(skel->links.send_signal_perf))) + goto disable_pmu; + } + + /* wait until child signal handler installed */ + CHECK(read(pipe_c2p[0], buf, 1) != 1, "pipe_read", "err %d\n", -errno); + + /* trigger the bpf send_signal */ + skel->bss->pid = pid; + skel->bss->sig = SIGUSR1; + skel->bss->signal_thread = signal_thread; + + /* notify child that bpf program can send_signal now */ + CHECK(write(pipe_p2c[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno); + + /* wait for result */ + err = read(pipe_c2p[0], buf, 1); + if (CHECK(err < 0, test_name, "reading pipe error: %s\n", strerror(errno))) + goto disable_pmu; + if (CHECK(err == 0, test_name, "reading pipe error: size 0\n")) { + err = -1; + goto disable_pmu; + } + + CHECK(buf[0] != '2', test_name, "incorrect result\n"); + + /* notify child safe to exit */ + CHECK(write(pipe_p2c[1], buf, 1) != 1, "pipe_write", "err %d\n", -errno); + +disable_pmu: + close(pmu_fd); +destroy_skel: + test_send_signal_kern__destroy(skel); +skel_open_load_failure: + close(pipe_c2p[0]); + close(pipe_p2c[1]); + wait(NULL); +} + +static void test_send_signal_tracepoint(bool signal_thread) +{ + test_send_signal_common(NULL, signal_thread, "tracepoint"); +} + +static void test_send_signal_perf(bool signal_thread) +{ + struct perf_event_attr attr = { + .sample_period = 1, + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_CPU_CLOCK, + }; + + test_send_signal_common(&attr, signal_thread, "perf_sw_event"); +} + +static void test_send_signal_nmi(bool signal_thread) +{ + struct perf_event_attr attr = { + .sample_period = 1, + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + }; + int pmu_fd; + + /* Some setups (e.g. virtual machines) might run with hardware + * perf events disabled. If this is the case, skip this test. + */ + pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */, + -1 /* cpu */, -1 /* group_fd */, 0 /* flags */); + if (pmu_fd == -1) { + if (errno == ENOENT) { + printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", + __func__); + test__skip(); + return; + } + /* Let the test fail with a more informative message */ + } else { + close(pmu_fd); + } + + test_send_signal_common(&attr, signal_thread, "perf_hw_event"); +} + +void test_send_signal(void) +{ + if (test__start_subtest("send_signal_tracepoint")) + test_send_signal_tracepoint(false); + if (test__start_subtest("send_signal_perf")) + test_send_signal_perf(false); + if (test__start_subtest("send_signal_nmi")) + test_send_signal_nmi(false); + if (test__start_subtest("send_signal_tracepoint_thread")) + test_send_signal_tracepoint(true); + if (test__start_subtest("send_signal_perf_thread")) + test_send_signal_perf(true); + if (test__start_subtest("send_signal_nmi_thread")) + test_send_signal_nmi(true); +} |