From patchwork Fri May 4 01:37:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 908411 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=netronome.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="GR42Fh2c"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40cZQY183bz9s3D for ; Fri, 4 May 2018 11:37:57 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751419AbeEDBhz (ORCPT ); Thu, 3 May 2018 21:37:55 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:45842 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301AbeEDBhp (ORCPT ); Thu, 3 May 2018 21:37:45 -0400 Received: by mail-qt0-f195.google.com with SMTP id j42-v6so25483391qtj.12 for ; Thu, 03 May 2018 18:37:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=rNjKEEq7b5RV9jPf6sDXq4UsSR5b3KZud9DYT/jsuXk=; b=GR42Fh2cSIVw8ZfBcMCSJ4fY0tIM4ooBPrbhfWha1nu5d/Ursrlmwh4dQJaWpmAfWE SsRDvXsLPEDQqLMhJrylvQTdM1AU9AdQ5JJzJasODHIkhSYodmTscRqHkMhBHYSKc1Ep prcDZdtjdGKnbkNpIgdETCFfGXP+gLb7VCCfPn34PENHAfmsLROOlADAfk9nWWBlr70G DZLYtDgjkGW13RagqlO0DHwHzk6aeku4/iv0CLzmgMe/mLN504UyerdEiyDdaTioEpY/ 09im2eyuEA2pjuqUEIP7WIaHFKDW87vlhu01lkdTD6Zq1xR76Cd6SxgPbPU+muCBqK43 fv4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=rNjKEEq7b5RV9jPf6sDXq4UsSR5b3KZud9DYT/jsuXk=; b=rKffFcXW+gP8lFoB8lYIo5tlUCs/2ZRS/sl/Rzui1w5omAcaA2HU4LyrLEQhkO0jZq 7Js3ThpvByiDVnaCKVM22pr0TQ0rKiw1Op+tjssM4i4NyFtf0X8Xly5C/AY2O/zPqOVP xONJI2iREoNucPPBfFGGOcCQI7wbCoTTs2x8p641KzB4ciU6n11XZx8ReDI7giCxN15v H8EvtLmbhvdqStiosmjld/EhJKhR1EY2CpVoqvKqOh2Ss9XY5RIk6pAE8U4JorIhWoNC 6rNKrZrPFbPibxCOtSBZgg+OXwwGegOp6mooGYPkxj1Fcw/5KWViqYDJA/k4oHwlnaLn qvAQ== X-Gm-Message-State: ALQs6tC+JA8ufKHIgF6Q5SqL/IOwNYS6u8G/OpYiSwPQnjJw+mSw1687 8WAIfwjVn/yUXw05zNxkFfGpow== X-Google-Smtp-Source: AB8JxZpF3Ju04zBn8Qit43WGsA3u4I3tJzK8rZouWlVMjQCSJEN4MuCfhW9985jBcfgn+7J3jEdcnA== X-Received: by 2002:a0c:a106:: with SMTP id d6-v6mr5926724qva.5.1525397864689; Thu, 03 May 2018 18:37:44 -0700 (PDT) Received: from jkicinski-Precision-T1700.netronome.com ([75.53.12.129]) by smtp.gmail.com with ESMTPSA id i89sm1866294qkh.76.2018.05.03.18.37.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 May 2018 18:37:44 -0700 (PDT) From: Jakub Kicinski To: alexei.starovoitov@gmail.com, daniel@iogearbox.net Cc: oss-drivers@netronome.com, netdev@vger.kernel.org, Jakub Kicinski Subject: [PATCH bpf-next 09/10] tools: bpftool: add simple perf event output reader Date: Thu, 3 May 2018 18:37:16 -0700 Message-Id: <20180504013717.29317-10-jakub.kicinski@netronome.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180504013717.29317-1-jakub.kicinski@netronome.com> References: <20180504013717.29317-1-jakub.kicinski@netronome.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 Reviewed-by: Quentin Monnet Acked-by: Alexei Starovoitov --- .../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 diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index c3eef8c972cd..a6258bc8ec4f 100644 --- 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. diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst index 20689a321ffe..564cb0d9692b 100644 --- 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** } diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 4e69782c4a79..892dbf095bff 100644 --- 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) diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 852d84a98acd..b301c9b315f1 100644 --- 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 ;; diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 9c620770c6ed..32f9e397a6c0 100644 --- 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 pinned_obj_table *tab) } } +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; diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index cbf8985da362..6173cd997e7a 100644 --- 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); diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 5efefde5f578..af6766e956ba 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -130,8 +130,7 @@ static int map_parse_fd(int *argc, char ***argv) 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 } }; diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c new file mode 100644 index 000000000000..c5a2ced8552d --- /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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#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; +}