From acbd06206bbbe59ffd2415c0b902dd244910e42e Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 13 Mar 2020 10:23:36 -0700 Subject: selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls Add vmlinux.h generation to selftest/bpf's Makefile. Use it from newly added test_vmlinux to trace nanosleep syscall using 5 different types of programs: - tracepoint; - raw tracepoint; - raw tracepoint w/ direct memory reads (tp_btf); - kprobe; - fentry. These programs are realistic variants of real-life tracing programs, excercising vmlinux.h's usage with tracing applications. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200313172336.1879637-5-andriin@fb.com --- tools/testing/selftests/bpf/prog_tests/vmlinux.c | 43 ++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/vmlinux.c (limited to 'tools/testing/selftests/bpf/prog_tests/vmlinux.c') diff --git a/tools/testing/selftests/bpf/prog_tests/vmlinux.c b/tools/testing/selftests/bpf/prog_tests/vmlinux.c new file mode 100644 index 000000000000..04939eda1325 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/vmlinux.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include "test_vmlinux.skel.h" + +#define MY_TV_NSEC 1337 + +static void nsleep() +{ + struct timespec ts = { .tv_nsec = MY_TV_NSEC }; + + (void)nanosleep(&ts, NULL); +} + +void test_vmlinux(void) +{ + int duration = 0, err; + struct test_vmlinux* skel; + struct test_vmlinux__bss *bss; + + skel = test_vmlinux__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + bss = skel->bss; + + err = test_vmlinux__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + /* trigger everything */ + nsleep(); + + CHECK(!bss->tp_called, "tp", "not called\n"); + CHECK(!bss->raw_tp_called, "raw_tp", "not called\n"); + CHECK(!bss->tp_btf_called, "tp_btf", "not called\n"); + CHECK(!bss->kprobe_called, "kprobe", "not called\n"); + CHECK(!bss->fentry_called, "fentry", "not called\n"); + +cleanup: + test_vmlinux__destroy(skel); +} -- cgit v1.2.3-70-g09d2 From 41078907eef0dd508d0999996d10683ae114c21a Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 13 Mar 2020 17:27:43 -0700 Subject: selftests/bpf: Fix nanosleep for real this time Amazingly, some libc implementations don't call __NR_nanosleep syscall from their nanosleep() APIs. Hammer it down with explicit syscall() call and never get back to it again. Also simplify code for timespec initialization. I verified that nanosleep is called w/ printk and in exactly same Linux image that is used in Travis CI. So it should both sleep and call correct syscall. v1->v2: - math is too hard, fix usec -> nsec convertion (Martin); - test_vmlinux has explicit nanosleep() call, convert that one as well. Fixes: 4e1fd25d19e8 ("selftests/bpf: Fix usleep() implementation") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200314002743.3782677-1-andriin@fb.com --- tools/testing/selftests/bpf/prog_tests/vmlinux.c | 2 +- tools/testing/selftests/bpf/test_progs.c | 16 ++++++---------- 2 files changed, 7 insertions(+), 11 deletions(-) (limited to 'tools/testing/selftests/bpf/prog_tests/vmlinux.c') diff --git a/tools/testing/selftests/bpf/prog_tests/vmlinux.c b/tools/testing/selftests/bpf/prog_tests/vmlinux.c index 04939eda1325..72310cfc6474 100644 --- a/tools/testing/selftests/bpf/prog_tests/vmlinux.c +++ b/tools/testing/selftests/bpf/prog_tests/vmlinux.c @@ -11,7 +11,7 @@ static void nsleep() { struct timespec ts = { .tv_nsec = MY_TV_NSEC }; - (void)nanosleep(&ts, NULL); + (void)syscall(__NR_nanosleep, &ts, NULL); } void test_vmlinux(void) diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index f85a06512541..dc12fd0de1c2 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -35,16 +35,12 @@ struct prog_test_def { */ int usleep(useconds_t usec) { - struct timespec ts; - - if (usec > 999999) { - ts.tv_sec = usec / 1000000; - ts.tv_nsec = usec % 1000000; - } else { - ts.tv_sec = 0; - ts.tv_nsec = usec; - } - return nanosleep(&ts, NULL); + struct timespec ts = { + .tv_sec = usec / 1000000, + .tv_nsec = (usec % 1000000) * 1000, + }; + + return syscall(__NR_nanosleep, &ts, NULL); } static bool should_run(struct test_selector *sel, int num, const char *name) -- cgit v1.2.3-70-g09d2