2026-09-11 10:51 UTC+0800 ~ Tianyi Chen <[email protected]>
> From: Tianyi Chen <[email protected]>
>
> Produce known ring buffer records and check complete plain, JSON and
> pretty JSON output. Exercise ID and pinned map selection, SIGINT and
> SIGTERM shutdown, empty streams and invalid map types or selectors.
>
> Also produce a perf event sample and check its existing header and raw
> payload output. Use a payload whose size plus the raw sample length
> field is aligned to eight bytes so the expected bytes exclude implicit
> perf padding.
>
> Assisted-by: LLM
> Signed-off-by: Tianyi Chen <[email protected]>
> ---
> .../bpf/prog_tests/bpftool_ringbuf.c | 425 ++++++++++++++++++
> .../selftests/bpf/progs/bpftool_ringbuf.c | 47 ++
> 2 files changed, 472 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/bpftool_ringbuf.c
> create mode 100644 tools/testing/selftests/bpf/progs/bpftool_ringbuf.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/bpftool_ringbuf.c
> b/tools/testing/selftests/bpf/prog_tests/bpftool_ringbuf.c
> new file mode 100644
> index 000000000000..1a4ae88c05a0
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/bpftool_ringbuf.c
> @@ -0,0 +1,425 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <ctype.h>
> +#include <fcntl.h>
> +#include <poll.h>
> +#include <signal.h>
> +#include <sys/mman.h>
> +#include <sys/wait.h>
> +#include <test_progs.h>
> +#include "bpftool_ringbuf.skel.h"
> +
> +#define WAIT_STEPS 500
> +#define WAIT_US 10000
> +
> +struct consumer {
> + pid_t pid;
> + int fd;
> +};
> +
> +static const char *bpftool_path(void)
> +{
> + const char *path = getenv("BPFTOOL");
> +
> + if (path)
> + return access(path, X_OK) ? NULL : path;
> + if (!access("./tools/sbin/bpftool", X_OK))
> + return "./tools/sbin/bpftool";
> + if (!access("../tools/sbin/bpftool", X_OK))
> + return "../tools/sbin/bpftool";
> + return NULL;
> +}
As bpf-ci's review says, please look into reusing the existing helpers
if possible.
> +
> +static void consumer_cleanup(struct consumer *child)
> +{
> + if (child->pid > 0) {
> + kill(child->pid, SIGKILL);
> + while (waitpid(child->pid, NULL, 0) < 0 && errno == EINTR)
> + ;
> + child->pid = -1;
> + }
> + if (child->fd >= 0) {
> + close(child->fd);
> + child->fd = -1;
> + }
> +}
> +
> +static bool consumer_start(struct consumer *child, int map_fd, const char
> *format,
> + const char *pin_path, const char *option,
> + bool pair, bool capture_errors)
> +{
> + struct bpf_map_info info = {};
> + __u32 len = sizeof(info);
> + const char *path = bpftool_path();
> + char *argv[12], id[16];
> + int out[2], ready[2], n = 0, err, err_fd;
> + struct pollfd pfd;
> +
> + if (!ASSERT_OK_PTR(path, "bpftool path (set BPFTOOL to override)") ||
> + !ASSERT_OK(bpf_map_get_info_by_fd(map_fd, &info, &len), "map info"))
> + return false;
> + snprintf(id, sizeof(id), "%u", info.id);
> + argv[n++] = (char *)path;
> + if (format)
> + argv[n++] = (char *)format;
> + argv[n++] = "map";
> + argv[n++] = "event_pipe";
> + argv[n++] = pin_path ? "pinned" : "id";
> + argv[n++] = pin_path ? (char *)pin_path : id;
> + if (option) {
> + argv[n++] = (char *)option;
> + argv[n++] = "0";
> + if (pair) {
> + argv[n++] = "index";
> + argv[n++] = "0";
> + }
> + }
> + argv[n] = NULL;
> + if (!ASSERT_OK(pipe2(out, O_CLOEXEC), "output pipe"))
> + return false;
> + if (!ASSERT_OK(pipe2(ready, O_CLOEXEC), "exec pipe")) {
> + close(out[0]);
> + close(out[1]);
> + return false;
> + }
> + child->pid = fork();
> + if (!child->pid) {
> + close(out[0]);
> + close(ready[0]);
> + err_fd = capture_errors ? out[1] : open("/dev/null", O_WRONLY);
> + if (dup2(out[1], STDOUT_FILENO) < 0 ||
> + dup2(err_fd, STDERR_FILENO) < 0)
> + goto exec_fail;
> + if (!capture_errors)
> + close(err_fd);
> + close(out[1]);
> + execv(path, argv);
> +exec_fail:
> + err = errno;
> + write(ready[1], &err, sizeof(err));
I think that ignoring the return value from write() can produce a
compiler warning (-Wunused-result).
[...]
Looks OK otherwise, thank you
