From 05e59e5fb0064c97a1c10921ecd549f2d4a58565 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 09 Oct 2024 06:14:40 +0000
Subject: [PATCH] add REDIRECT
---
kernel/samples/bpf/trace_output_user.c | 103 ++++++++++++++++++++++++++-------------------------
1 files changed, 52 insertions(+), 51 deletions(-)
diff --git a/kernel/samples/bpf/trace_output_user.c b/kernel/samples/bpf/trace_output_user.c
index 4837d73..364b987 100644
--- a/kernel/samples/bpf/trace_output_user.c
+++ b/kernel/samples/bpf/trace_output_user.c
@@ -1,29 +1,10 @@
-/* This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- */
+// SPDX-License-Identifier: GPL-2.0-only
#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdbool.h>
-#include <string.h>
#include <fcntl.h>
#include <poll.h>
-#include <linux/perf_event.h>
-#include <linux/bpf.h>
-#include <errno.h>
-#include <assert.h>
-#include <sys/syscall.h>
-#include <sys/ioctl.h>
-#include <sys/mman.h>
#include <time.h>
#include <signal.h>
-#include <libbpf.h>
-#include "bpf_load.h"
-#include "perf-sys.h"
-#include "trace_helpers.h"
-
-static int pmu_fd;
+#include <bpf/libbpf.h>
static __u64 time_get_ns(void)
{
@@ -34,12 +15,12 @@
}
static __u64 start_time;
+static __u64 cnt;
#define MAX_CNT 100000ll
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
{
- static __u64 cnt;
struct {
__u64 pid;
__u64 cookie;
@@ -48,7 +29,7 @@
if (e->cookie != 0x12345678) {
printf("BUG pid %llx cookie %llx sized %d\n",
e->pid, e->cookie, size);
- return LIBBPF_PERF_EVENT_ERROR;
+ return;
}
cnt++;
@@ -56,51 +37,71 @@
if (cnt == MAX_CNT) {
printf("recv %lld events per sec\n",
MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
- return LIBBPF_PERF_EVENT_DONE;
+ return;
}
-
- return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(void)
-{
- struct perf_event_attr attr = {
- .sample_type = PERF_SAMPLE_RAW,
- .type = PERF_TYPE_SOFTWARE,
- .config = PERF_COUNT_SW_BPF_OUTPUT,
- };
- int key = 0;
-
- pmu_fd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
-
- assert(pmu_fd >= 0);
- assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fd, BPF_ANY) == 0);
- ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
}
int main(int argc, char **argv)
{
+ struct perf_buffer_opts pb_opts = {};
+ struct bpf_link *link = NULL;
+ struct bpf_program *prog;
+ struct perf_buffer *pb;
+ struct bpf_object *obj;
+ int map_fd, ret = 0;
char filename[256];
FILE *f;
- int ret;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
-
- if (load_bpf_file(filename)) {
- printf("%s", bpf_log_buf);
- return 1;
+ obj = bpf_object__open_file(filename, NULL);
+ if (libbpf_get_error(obj)) {
+ fprintf(stderr, "ERROR: opening BPF object file failed\n");
+ return 0;
}
- test_bpf_perf_event();
+ /* load BPF program */
+ if (bpf_object__load(obj)) {
+ fprintf(stderr, "ERROR: loading BPF object file failed\n");
+ goto cleanup;
+ }
- if (perf_event_mmap(pmu_fd) < 0)
+ map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+ if (map_fd < 0) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+ if (libbpf_get_error(prog)) {
+ fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+ goto cleanup;
+ }
+
+ link = bpf_program__attach(prog);
+ if (libbpf_get_error(link)) {
+ fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+ link = NULL;
+ goto cleanup;
+ }
+
+ pb_opts.sample_cb = print_bpf_output;
+ pb = perf_buffer__new(map_fd, 8, &pb_opts);
+ ret = libbpf_get_error(pb);
+ if (ret) {
+ printf("failed to setup perf_buffer: %d\n", ret);
return 1;
+ }
f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
(void) f;
start_time = time_get_ns();
- ret = perf_event_poller(pmu_fd, print_bpf_output);
+ while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+ }
kill(0, SIGINT);
+
+cleanup:
+ bpf_link__destroy(link);
+ bpf_object__close(obj);
return ret;
}
--
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