From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Thu, 3 May 2018 18:37:16 -0700
Subject: tools: bpftool: add simple perf event output reader
Patch-mainline: v4.18-rc1
Git-commit: f412eed9dfdeeb6becd7de2ffe8b5d0a8b3f81ca
References: bsc#1109837
Users of BPF sooner or later discover perf_event_output() helpers
and BPF_MAP_TYPE_PERF_EVENT_ARRAY. Dumping this array type is
not possible, however, we can add simple reading of perf events.
Create a new event_pipe subcommand for maps, this sub command
will only work with BPF_MAP_TYPE_PERF_EVENT_ARRAY maps.
Parts of the code from samples/bpf/trace_output_user.c.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
tools/bpf/bpftool/Documentation/bpftool-map.rst | 29 +-
tools/bpf/bpftool/Documentation/bpftool.rst | 2
tools/bpf/bpftool/Makefile | 7
tools/bpf/bpftool/bash-completion/bpftool | 36 ++
tools/bpf/bpftool/common.c | 19 +
tools/bpf/bpftool/main.h | 4
tools/bpf/bpftool/map.c | 19 -
tools/bpf/bpftool/map_perf_ring.c | 347 ++++++++++++++++++++++++
8 files changed, 444 insertions(+), 19 deletions(-)
create mode 100644 tools/bpf/bpftool/map_perf_ring.c
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -22,12 +22,13 @@ MAP COMMANDS
=============
| **bpftool** **map { show | list }** [*MAP*]
-| **bpftool** **map dump** *MAP*
-| **bpftool** **map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*]
-| **bpftool** **map lookup** *MAP* **key** *DATA*
-| **bpftool** **map getnext** *MAP* [**key** *DATA*]
-| **bpftool** **map delete** *MAP* **key** *DATA*
-| **bpftool** **map pin** *MAP* *FILE*
+| **bpftool** **map dump** *MAP*
+| **bpftool** **map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*]
+| **bpftool** **map lookup** *MAP* **key** *DATA*
+| **bpftool** **map getnext** *MAP* [**key** *DATA*]
+| **bpftool** **map delete** *MAP* **key** *DATA*
+| **bpftool** **map pin** *MAP* *FILE*
+| **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]
| **bpftool** **map help**
|
| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
@@ -76,6 +77,22 @@ DESCRIPTION
Note: *FILE* must be located in *bpffs* mount.
+ **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]
+ Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map.
+
+ Install perf rings into a perf event array map and dump
+ output of any bpf_perf_event_output() call in the kernel.
+ By default read the number of CPUs on the system and
+ install perf ring for each CPU in the corresponding index
+ in the array.
+
+ If **cpu** and **index** are specified, install perf ring
+ for given **cpu** at **index** in the array (single ring).
+
+ Note that installing a perf ring into an array will silently
+ replace any existing ring. Any other application will stop
+ receiving events if it installed its rings earlier.
+
**bpftool map help**
Print short help message.
--- a/tools/bpf/bpftool/Documentation/bpftool.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool.rst
@@ -23,7 +23,7 @@ SYNOPSIS
*MAP-COMMANDS* :=
{ **show** | **list** | **dump** | **update** | **lookup** | **getnext** | **delete**
- | **pin** | **help** }
+ | **pin** | **event_pipe** | **help** }
*PROG-COMMANDS* := { **show** | **list** | **dump jited** | **dump xlated** | **pin**
| **load** | **help** }
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -39,7 +39,12 @@ CC = gcc
CFLAGS += -O2
CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow -Wno-missing-field-initializers
-CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/
+CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
+ -I$(srctree)/kernel/bpf/ \
+ -I$(srctree)/tools/include \
+ -I$(srctree)/tools/include/uapi \
+ -I$(srctree)/tools/lib/bpf \
+ -I$(srctree)/tools/perf
CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"'
LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -1,6 +1,6 @@
# bpftool(8) bash completion -*- shell-script -*-
#
-# Copyright (C) 2017 Netronome Systems, Inc.
+# Copyright (C) 2017-2018 Netronome Systems, Inc.
#
# This software is dual licensed under the GNU General License
# Version 2, June 1991 as shown in the file COPYING in the top-level
@@ -79,6 +79,14 @@ _bpftool_get_map_ids()
command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
}
+_bpftool_get_perf_map_ids()
+{
+ COMPREPLY+=( $( compgen -W "$( bpftool -jp map 2>&1 | \
+ command grep -C2 perf_event_array | \
+ command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
+}
+
+
_bpftool_get_prog_ids()
{
COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
@@ -359,10 +367,34 @@ _bpftool()
fi
return 0
;;
+ event_pipe)
+ case $prev in
+ $command)
+ COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )
+ return 0
+ ;;
+ id)
+ _bpftool_get_perf_map_ids
+ return 0
+ ;;
+ cpu)
+ return 0
+ ;;
+ index)
+ return 0
+ ;;
+ *)
+ _bpftool_once_attr 'cpu'
+ _bpftool_once_attr 'index'
+ return 0
+ ;;
+ esac
+ ;;
*)
[[ $prev == $object ]] && \
COMPREPLY=( $( compgen -W 'delete dump getnext help \
- lookup pin show list update' -- "$cur" ) )
+ lookup pin event_pipe show list update' -- \
+ "$cur" ) )
;;
esac
;;
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -331,6 +331,16 @@ char *get_fdinfo(int fd, const char *key
return NULL;
}
+void print_data_json(uint8_t *data, size_t len)
+{
+ unsigned int i;
+
+ jsonw_start_array(json_wtr);
+ for (i = 0; i < len; i++)
+ jsonw_printf(json_wtr, "%d", data[i]);
+ jsonw_end_array(json_wtr);
+}
+
void print_hex_data_json(uint8_t *data, size_t len)
{
unsigned int i;
@@ -421,6 +431,15 @@ void delete_pinned_obj_table(struct pinn
}
}
+unsigned int get_page_size(void)
+{
+ static int result;
+
+ if (!result)
+ result = getpagesize();
+ return result;
+}
+
unsigned int get_possible_cpus(void)
{
static unsigned int result;
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -117,14 +117,18 @@ int do_pin_fd(int fd, const char *name);
int do_prog(int argc, char **arg);
int do_map(int argc, char **arg);
+int do_event_pipe(int argc, char **argv);
int do_cgroup(int argc, char **arg);
int prog_parse_fd(int *argc, char ***argv);
+int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len);
void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
const char *arch);
+void print_data_json(uint8_t *data, size_t len);
void print_hex_data_json(uint8_t *data, size_t len);
+unsigned int get_page_size(void);
unsigned int get_possible_cpus(void);
const char *ifindex_to_bfd_name_ns(__u32 ifindex, __u64 ns_dev, __u64 ns_ino);
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -130,8 +130,7 @@ static int map_parse_fd(int *argc, char
return -1;
}
-static int
-map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
+int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
{
int err;
int fd;
@@ -817,12 +816,13 @@ static int do_help(int argc, char **argv
fprintf(stderr,
"Usage: %s %s { show | list } [MAP]\n"
- " %s %s dump MAP\n"
- " %s %s update MAP key DATA value VALUE [UPDATE_FLAGS]\n"
- " %s %s lookup MAP key DATA\n"
- " %s %s getnext MAP [key DATA]\n"
- " %s %s delete MAP key DATA\n"
- " %s %s pin MAP FILE\n"
+ " %s %s dump MAP\n"
+ " %s %s update MAP key DATA value VALUE [UPDATE_FLAGS]\n"
+ " %s %s lookup MAP key DATA\n"
+ " %s %s getnext MAP [key DATA]\n"
+ " %s %s delete MAP key DATA\n"
+ " %s %s pin MAP FILE\n"
+ " %s %s event_pipe MAP [cpu N index M]\n"
" %s %s help\n"
"\n"
" MAP := { id MAP_ID | pinned FILE }\n"
@@ -834,7 +834,7 @@ static int do_help(int argc, char **argv
"",
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
- bin_name, argv[-2], bin_name, argv[-2]);
+ bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
return 0;
}
@@ -849,6 +849,7 @@ static const struct cmd cmds[] = {
{ "getnext", do_getnext },
{ "delete", do_delete },
{ "pin", do_pin },
+ { "event_pipe", do_event_pipe },
{ 0 }
};
--- /dev/null
+++ b/tools/bpf/bpftool/map_perf_ring.c
@@ -0,0 +1,347 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2018 Netronome Systems, Inc. */
+/* 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.
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <libbpf.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <linux/bpf.h>
+#include <linux/perf_event.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+
+#include <bpf.h>
+#include <perf-sys.h>
+
+#include "main.h"
+
+#define MMAP_PAGE_CNT 16
+
+static bool stop;
+
+struct event_ring_info {
+ int fd;
+ int key;
+ unsigned int cpu;
+ void *mem;
+};
+
+struct perf_event_sample {
+ struct perf_event_header header;
+ __u32 size;
+ unsigned char data[];
+};
+
+static void int_exit(int signo)
+{
+ fprintf(stderr, "Stopping...\n");
+ stop = true;
+}
+
+static void
+print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e)
+{
+ struct {
+ struct perf_event_header header;
+ __u64 id;
+ __u64 lost;
+ } *lost = (void *)e;
+ struct timespec ts;
+
+ if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
+ perror("Can't read clock for timestamp");
+ return;
+ }
+
+ if (json_output) {
+ jsonw_start_object(json_wtr);
+ jsonw_name(json_wtr, "timestamp");
+ jsonw_uint(json_wtr, ts.tv_sec * 1000000000ull + ts.tv_nsec);
+ jsonw_name(json_wtr, "type");
+ jsonw_uint(json_wtr, e->header.type);
+ jsonw_name(json_wtr, "cpu");
+ jsonw_uint(json_wtr, ring->cpu);
+ jsonw_name(json_wtr, "index");
+ jsonw_uint(json_wtr, ring->key);
+ if (e->header.type == PERF_RECORD_SAMPLE) {
+ jsonw_name(json_wtr, "data");
+ print_data_json(e->data, e->size);
+ } else if (e->header.type == PERF_RECORD_LOST) {
+ jsonw_name(json_wtr, "lost");
+ jsonw_start_object(json_wtr);
+ jsonw_name(json_wtr, "id");
+ jsonw_uint(json_wtr, lost->id);
+ jsonw_name(json_wtr, "count");
+ jsonw_uint(json_wtr, lost->lost);
+ jsonw_end_object(json_wtr);
+ }
+ jsonw_end_object(json_wtr);
+ } else {
+ if (e->header.type == PERF_RECORD_SAMPLE) {
+ printf("== @%ld.%ld CPU: %d index: %d =====\n",
+ (long)ts.tv_sec, ts.tv_nsec,
+ ring->cpu, ring->key);
+ fprint_hex(stdout, e->data, e->size, " ");
+ printf("\n");
+ } else if (e->header.type == PERF_RECORD_LOST) {
+ printf("lost %lld events\n", lost->lost);
+ } else {
+ printf("unknown event type=%d size=%d\n",
+ e->header.type, e->header.size);
+ }
+ }
+}
+
+static void
+perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len)
+{
+ volatile struct perf_event_mmap_page *header = ring->mem;
+ __u64 buffer_size = MMAP_PAGE_CNT * get_page_size();
+ __u64 data_tail = header->data_tail;
+ __u64 data_head = header->data_head;
+ void *base, *begin, *end;
+
+ asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
+ if (data_head == data_tail)
+ return;
+
+ base = ((char *)header) + get_page_size();
+
+ begin = base + data_tail % buffer_size;
+ end = base + data_head % buffer_size;
+
+ while (begin != end) {
+ struct perf_event_sample *e;
+
+ e = begin;
+ if (begin + e->header.size > base + buffer_size) {
+ long len = base + buffer_size - begin;
+
+ if (*buf_len < e->header.size) {
+ free(*buf);
+ *buf = malloc(e->header.size);
+ if (!*buf) {
+ fprintf(stderr,
+ "can't allocate memory");
+ stop = true;
+ return;
+ }
+ *buf_len = e->header.size;
+ }
+
+ memcpy(*buf, begin, len);
+ memcpy(*buf + len, base, e->header.size - len);
+ e = (void *)*buf;
+ begin = base + e->header.size - len;
+ } else if (begin + e->header.size == base + buffer_size) {
+ begin = base;
+ } else {
+ begin += e->header.size;
+ }
+
+ print_bpf_output(ring, e);
+ }
+
+ __sync_synchronize(); /* smp_mb() */
+ header->data_tail = data_head;
+}
+
+static int perf_mmap_size(void)
+{
+ return get_page_size() * (MMAP_PAGE_CNT + 1);
+}
+
+static void *perf_event_mmap(int fd)
+{
+ int mmap_size = perf_mmap_size();
+ void *base;
+
+ base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (base == MAP_FAILED) {
+ p_err("event mmap failed: %s\n", strerror(errno));
+ return NULL;
+ }
+
+ return base;
+}
+
+static void perf_event_unmap(void *mem)
+{
+ if (munmap(mem, perf_mmap_size()))
+ fprintf(stderr, "Can't unmap ring memory!\n");
+}
+
+static int bpf_perf_event_open(int map_fd, int key, int cpu)
+{
+ struct perf_event_attr attr = {
+ .sample_type = PERF_SAMPLE_RAW,
+ .type = PERF_TYPE_SOFTWARE,
+ .config = PERF_COUNT_SW_BPF_OUTPUT,
+ };
+ int pmu_fd;
+
+ pmu_fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
+ if (pmu_fd < 0) {
+ p_err("failed to open perf event %d for CPU %d", key, cpu);
+ return -1;
+ }
+
+ if (bpf_map_update_elem(map_fd, &key, &pmu_fd, BPF_ANY)) {
+ p_err("failed to update map for event %d for CPU %d", key, cpu);
+ goto err_close;
+ }
+ if (ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) {
+ p_err("failed to enable event %d for CPU %d", key, cpu);
+ goto err_close;
+ }
+
+ return pmu_fd;
+
+err_close:
+ close(pmu_fd);
+ return -1;
+}
+
+int do_event_pipe(int argc, char **argv)
+{
+ int i, nfds, map_fd, index = -1, cpu = -1;
+ struct bpf_map_info map_info = {};
+ struct event_ring_info *rings;
+ size_t tmp_buf_sz = 0;
+ void *tmp_buf = NULL;
+ struct pollfd *pfds;
+ __u32 map_info_len;
+ bool do_all = true;
+
+ map_info_len = sizeof(map_info);
+ map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
+ if (map_fd < 0)
+ return -1;
+
+ if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
+ p_err("map is not a perf event array");
+ goto err_close_map;
+ }
+
+ while (argc) {
+ if (argc < 2)
+ BAD_ARG();
+
+ if (is_prefix(*argv, "cpu")) {
+ char *endptr;
+
+ NEXT_ARG();
+ cpu = strtoul(*argv, &endptr, 0);
+ if (*endptr) {
+ p_err("can't parse %s as CPU ID", **argv);
+ goto err_close_map;
+ }
+
+ NEXT_ARG();
+ } else if (is_prefix(*argv, "index")) {
+ char *endptr;
+
+ NEXT_ARG();
+ index = strtoul(*argv, &endptr, 0);
+ if (*endptr) {
+ p_err("can't parse %s as index", **argv);
+ goto err_close_map;
+ }
+
+ NEXT_ARG();
+ } else {
+ BAD_ARG();
+ }
+
+ do_all = false;
+ }
+
+ if (!do_all) {
+ if (index == -1 || cpu == -1) {
+ p_err("cpu and index must be specified together");
+ goto err_close_map;
+ }
+
+ nfds = 1;
+ } else {
+ nfds = min(get_possible_cpus(), map_info.max_entries);
+ cpu = 0;
+ index = 0;
+ }
+
+ rings = calloc(nfds, sizeof(rings[0]));
+ if (!rings)
+ goto err_close_map;
+
+ pfds = calloc(nfds, sizeof(pfds[0]));
+ if (!pfds)
+ goto err_free_rings;
+
+ for (i = 0; i < nfds; i++) {
+ rings[i].cpu = cpu + i;
+ rings[i].key = index + i;
+
+ rings[i].fd = bpf_perf_event_open(map_fd, rings[i].key,
+ rings[i].cpu);
+ if (rings[i].fd < 0)
+ goto err_close_fds_prev;
+
+ rings[i].mem = perf_event_mmap(rings[i].fd);
+ if (!rings[i].mem)
+ goto err_close_fds_current;
+
+ pfds[i].fd = rings[i].fd;
+ pfds[i].events = POLLIN;
+ }
+
+ signal(SIGINT, int_exit);
+ signal(SIGHUP, int_exit);
+ signal(SIGTERM, int_exit);
+
+ if (json_output)
+ jsonw_start_array(json_wtr);
+
+ while (!stop) {
+ poll(pfds, nfds, 200);
+ for (i = 0; i < nfds; i++)
+ perf_event_read(&rings[i], &tmp_buf, &tmp_buf_sz);
+ }
+ free(tmp_buf);
+
+ if (json_output)
+ jsonw_end_array(json_wtr);
+
+ for (i = 0; i < nfds; i++) {
+ perf_event_unmap(rings[i].mem);
+ close(rings[i].fd);
+ }
+ free(pfds);
+ free(rings);
+ close(map_fd);
+
+ return 0;
+
+err_close_fds_prev:
+ while (i--) {
+ perf_event_unmap(rings[i].mem);
+err_close_fds_current:
+ close(rings[i].fd);
+ }
+ free(pfds);
+err_free_rings:
+ free(rings);
+err_close_map:
+ close(map_fd);
+ return -1;
+}