On Mon, Dec 20, 2021 at 9:54 PM Hengqi Chen <hengqi.chen@xxxxxxxxx> wrote:
>
> Add tests for the newly added BPF_KPROBE_SYSCALL/BPF_KRETPROBE_SYSCALL macros.
>
> Signed-off-by: Hengqi Chen <hengqi.chen@xxxxxxxxx>
> ---
> .../selftests/bpf/prog_tests/kprobe_syscall.c | 40 ++++++++++++++++++
> .../selftests/bpf/progs/test_kprobe_syscall.c | 41 +++++++++++++++++++
> 2 files changed, 81 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/kprobe_syscall.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_kprobe_syscall.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/kprobe_syscall.c
> new file mode 100644
> index 000000000000..a1fad70bbb69
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_syscall.c
> @@ -0,0 +1,40 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Hengqi Chen */
> +
> +#include <test_progs.h>
> +#include <sys/types.h>
> +#include <sys/socket.h>
> +#include "test_kprobe_syscall.skel.h"
> +
> +void test_kprobe_syscall(void)
> +{
> + struct test_kprobe_syscall *skel;
> + int err, fd = 0;
> +
> + skel = test_kprobe_syscall__open();
> + if (!ASSERT_OK_PTR(skel, "could not open BPF object"))
> + return;
> +
> + skel->rodata->my_pid = getpid();
> +
> + err = test_kprobe_syscall__load(skel);
> + if (!ASSERT_OK(err, "could not load BPF object"))
> + goto cleanup;
> +
> + err = test_kprobe_syscall__attach(skel);
> + if (!ASSERT_OK(err, "could not attach BPF object"))
> + goto cleanup;
> +
> + fd = socket(AF_UNIX, SOCK_STREAM, 0);
> +
> + ASSERT_GT(fd, 0, "socket failed");
> + ASSERT_EQ(skel->bss->domain, AF_UNIX, "BPF_KPROBE_SYSCALL failed");
> + ASSERT_EQ(skel->bss->type, SOCK_STREAM, "BPF_KPROBE_SYSCALL failed");
> + ASSERT_EQ(skel->bss->protocol, 0, "BPF_KPROBE_SYSCALL failed");
> + ASSERT_EQ(skel->bss->fd, fd, "BPF_KRETPROBE_SYSCALL failed");
> +
> +cleanup:
> + if (fd)
> + close(fd);
> + test_kprobe_syscall__destroy(skel);
> +}
> diff --git a/tools/testing/selftests/bpf/progs/test_kprobe_syscall.c b/tools/testing/selftests/bpf/progs/test_kprobe_syscall.c
> new file mode 100644
> index 000000000000..ecef9d19007c
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_kprobe_syscall.c
> @@ -0,0 +1,41 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Hengqi Chen */
> +
> +#include "vmlinux.h"
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include <bpf/bpf_core_read.h>
> +
> +const volatile pid_t my_pid = 0;
> +int domain = 0;
> +int type = 0;
> +int protocol = 0;
> +int fd = 0;
> +
> +SEC("kprobe/__x64_sys_socket")
> +int BPF_KPROBE_SYSCALL(socket_enter, int d, int t, int p)
> +{
> + pid_t pid = bpf_get_current_pid_tgid() >> 32;
> +
> + if (pid != my_pid)
> + return 0;
> +
> + domain = d;
> + type = t;
> + protocol = p;
> + return 0;
> +}
> +
> +SEC("kretprobe/__x64_sys_socket")
oh, please also use SYS_PREFIX instead of hard-coding __x64. This is
very x86-64-specific and we have other architectures tested by
selftests, so this makes it automatically fail on non-x86_64.
If you get a chance, try also cleaning up other __x64_ uses in the
selftests as a separate patch. Thank you!
> +int BPF_KRETPROBE_SYSCALL(socket_exit, int ret)
> +{
> + pid_t pid = bpf_get_current_pid_tgid() >> 32;
> +
> + if (pid != my_pid)
> + return 0;
> +
> + fd = ret;
> + return 0;
> +}
> +
> +char _license[] SEC("license") = "GPL";
> --
> 2.30.2
