From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD4F3C2BB1D for ; Fri, 13 Mar 2020 11:52:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8802F206EB for ; Fri, 13 Mar 2020 11:52:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gBHg7tRu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726713AbgCMLww (ORCPT ); Fri, 13 Mar 2020 07:52:52 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:34776 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726682AbgCMLwv (ORCPT ); Fri, 13 Mar 2020 07:52:51 -0400 Received: by mail-pg1-f194.google.com with SMTP id t3so4879786pgn.1; Fri, 13 Mar 2020 04:52:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4TWzdpqSMn20ygSdwtyFCcqWtUo8JP4puvTIn/hvZGQ=; b=gBHg7tRuZExNyuV9se7rNGIdK7w7N2pczy0vAyL1mwwDBaErVOdQJST9cjpRvIEPsg 8upWweufOmWquiwlmIvZ/hf82WUm1xyxkweCX+n+7s05bgS7vZ4Qerno6JFoSQnKeahm 45N3L/HW9gMG2DCJs5NE+3n9VYVfLdRPuyr0qCWssL6lzlTBxJ5s1il5LM6hHrwTt3lf HPNXaNCade89pm+Rsao1LmErVbgt5ioTAuSNXHd7K7pnosIc1dMm+56n236pMgeoPHv4 vy2UqGLXsmnEVhq/lqdd9UJlQTrCGDAaKN+mRG4UyALHJdUf2zJCFzM0kyXAHV94Odf+ 7acw== 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:mime-version:content-transfer-encoding; bh=4TWzdpqSMn20ygSdwtyFCcqWtUo8JP4puvTIn/hvZGQ=; b=cPfkyfAvqna1Tp6ufZ/uH+agQvY/hfrBzUBuiVPFhdmrBuB7hSHnpzgw28j0hGU1wg Sq2Gi9VLos9n+K+LVPfsJV4UVWko6RV+hePKNzJeS5TTdV58oqasqcv7FIvqDkkExt4D cUuVTE54fAWxJeC8qvzA3F9UhIi0ay0n6CTJYIj3eBzAHCdwrbTh/JBjAICQslLFtbKo pZH8ApPX8PCp20h8p0aNaByelgFGatQ5nQ+PLKGqP/RP4r61rXWZE3tA4Su1jW3LokY6 yPD8HlDnVqNnOdljf5lDbTf/AbZT7nEOSCk4dyK5Qz3fAlbWJ2oYMKAolC3gs5k0vQd5 QsvQ== X-Gm-Message-State: ANhLgQ2P1oAjSKyULfUuwhgfLXcoVOtaVPRAx9TfOLSxK/xLLIN1ZRlW 7XgOh1KQFcTsxEu9xH0qAg== X-Google-Smtp-Source: ADFU+vvnkP5m+Z9fw1ofpNM21xBTJaJ7MKYCxZWEljrvhSvrXpTlWF+GvzqnntpfRrENDONKy+OMXQ== X-Received: by 2002:a05:6a00:c8:: with SMTP id e8mr10442771pfj.131.1584100370339; Fri, 13 Mar 2020 04:52:50 -0700 (PDT) Received: from localhost.localdomain ([110.35.161.54]) by smtp.gmail.com with ESMTPSA id r14sm2095151pjj.48.2020.03.13.04.52.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Mar 2020 04:52:49 -0700 (PDT) From: "Daniel T. Lee" To: Daniel Borkmann , Alexei Starovoitov Cc: John Fastabend , Andrii Nakryiko , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH bpf-next v3 2/2] samples: bpf: refactor perf_event user program with libbpf bpf_link Date: Fri, 13 Mar 2020 20:52:20 +0900 Message-Id: <20200313115220.29073-3-danieltimlee@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200313115220.29073-1-danieltimlee@gmail.com> References: <20200313115220.29073-1-danieltimlee@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The bpf_program__attach of libbpf(using bpf_link) is much more intuitive than the previous method using ioctl. bpf_program__attach_perf_event manages the enable of perf_event and attach of BPF programs to it, so there's no neeed to do this directly with ioctl. In addition, bpf_link provides consistency in the use of API because it allows disable (detach, destroy) for multiple events to be treated as one bpf_link__destroy. Also, bpf_link__destroy manages the close() of perf_event fd. This commit refactors samples that attach the bpf program to perf_event by using libbbpf instead of ioctl. Also the bpf_load in the samples were removed and migrated to use libbbpf API. Signed-off-by: Daniel T. Lee --- Changes in v2: - check memory allocation is successful - clean up allocated memory on error Changes in v3: - Improve pointer error check (IS_ERR()) - change to calloc for easier destroy of bpf_link - remove perf_event fd list since bpf_link handles fd - use newer bpf_object__{open/load} API instead of bpf_prog_load - perf_event for _SC_NPROCESSORS_ONLN instead of _SC_NPROCESSORS_CONF - find program with name explicitly instead of bpf_program__next - unconditional bpf_link__destroy() on cleanup - return error code on int_exit samples/bpf/Makefile | 4 +- samples/bpf/sampleip_user.c | 100 ++++++++++++++++++++++----------- samples/bpf/trace_event_user.c | 89 ++++++++++++++++++++--------- 3 files changed, 131 insertions(+), 62 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index ff0061467dd3..424f6fe7ce38 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -88,8 +88,8 @@ xdp2-objs := xdp1_user.o xdp_router_ipv4-objs := xdp_router_ipv4_user.o test_current_task_under_cgroup-objs := bpf_load.o $(CGROUP_HELPERS) \ test_current_task_under_cgroup_user.o -trace_event-objs := bpf_load.o trace_event_user.o $(TRACE_HELPERS) -sampleip-objs := bpf_load.o sampleip_user.o $(TRACE_HELPERS) +trace_event-objs := trace_event_user.o $(TRACE_HELPERS) +sampleip-objs := sampleip_user.o $(TRACE_HELPERS) tc_l2_redirect-objs := bpf_load.o tc_l2_redirect_user.o lwt_len_hist-objs := bpf_load.o lwt_len_hist_user.o xdp_tx_iptunnel-objs := xdp_tx_iptunnel_user.o diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c index b0f115f938bc..05eca7b00e22 100644 --- a/samples/bpf/sampleip_user.c +++ b/samples/bpf/sampleip_user.c @@ -10,21 +10,23 @@ #include #include #include -#include #include #include #include -#include +#include #include -#include "bpf_load.h" #include "perf-sys.h" #include "trace_helpers.h" +#define __must_check +#include + #define DEFAULT_FREQ 99 #define DEFAULT_SECS 5 #define MAX_IPS 8192 #define PAGE_OFFSET 0xffff880000000000 +static int map_fd; static int nr_cpus; static void usage(void) @@ -34,9 +36,10 @@ static void usage(void) printf(" duration # sampling duration (seconds), default 5\n"); } -static int sampling_start(int *pmu_fd, int freq) +static int sampling_start(int freq, struct bpf_program *prog, + struct bpf_link *links[]) { - int i; + int i, pmu_fd; struct perf_event_attr pe_sample_attr = { .type = PERF_TYPE_SOFTWARE, @@ -47,26 +50,29 @@ static int sampling_start(int *pmu_fd, int freq) }; for (i = 0; i < nr_cpus; i++) { - pmu_fd[i] = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i, + pmu_fd = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i, -1 /* group_fd */, 0 /* flags */); - if (pmu_fd[i] < 0) { + if (pmu_fd < 0) { fprintf(stderr, "ERROR: Initializing perf sampling\n"); return 1; } - assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, - prog_fd[0]) == 0); - assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0); + links[i] = bpf_program__attach_perf_event(prog, pmu_fd); + if (IS_ERR(links[i])) { + fprintf(stderr, "ERROR: Attach perf event\n"); + close(pmu_fd); + return 1; + } } return 0; } -static void sampling_end(int *pmu_fd) +static void sampling_end(struct bpf_link *links[]) { int i; for (i = 0; i < nr_cpus; i++) - close(pmu_fd[i]); + bpf_link__destroy(links[i]); } struct ipcount { @@ -128,14 +134,17 @@ static void print_ip_map(int fd) static void int_exit(int sig) { printf("\n"); - print_ip_map(map_fd[0]); + print_ip_map(map_fd); exit(0); } int main(int argc, char **argv) { + int opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS, error = 0; + struct bpf_program *prog; + struct bpf_object *obj; + struct bpf_link **links; char filename[256]; - int *pmu_fd, opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS; /* process arguments */ while ((opt = getopt(argc, argv, "F:h")) != -1) { @@ -163,38 +172,61 @@ int main(int argc, char **argv) } /* create perf FDs for each CPU */ - nr_cpus = sysconf(_SC_NPROCESSORS_CONF); - pmu_fd = malloc(nr_cpus * sizeof(int)); - if (pmu_fd == NULL) { - fprintf(stderr, "ERROR: malloc of pmu_fd\n"); - return 1; + nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); + links = calloc(nr_cpus, sizeof(struct bpf_link *)); + if (!links) { + fprintf(stderr, "ERROR: malloc of links\n"); + error = 1; + goto cleanup; } - /* load BPF program */ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); - if (load_bpf_file(filename)) { - fprintf(stderr, "ERROR: loading BPF program (errno %d):\n", - errno); - if (strcmp(bpf_log_buf, "") == 0) - fprintf(stderr, "Try: ulimit -l unlimited\n"); - else - fprintf(stderr, "%s", bpf_log_buf); - return 1; + obj = bpf_object__open_file(filename, NULL); + if (IS_ERR(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + error = 1; + goto cleanup; + } + + prog = bpf_object__find_program_by_name(obj, "do_sample"); + if (!prog) { + fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); + error = 1; + goto cleanup; } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + error = 1; + goto cleanup; + } + + map_fd = bpf_object__find_map_fd_by_name(obj, "ip_map"); + if (map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + error = 1; + goto cleanup; + } + signal(SIGINT, int_exit); signal(SIGTERM, int_exit); /* do sampling */ printf("Sampling at %d Hertz for %d seconds. Ctrl-C also ends.\n", freq, secs); - if (sampling_start(pmu_fd, freq) != 0) - return 1; + if (sampling_start(freq, prog, links) != 0) { + error = 1; + goto cleanup; + } sleep(secs); - sampling_end(pmu_fd); - free(pmu_fd); +cleanup: + sampling_end(links); /* output sample counts */ - print_ip_map(map_fd[0]); + if (!error) + print_ip_map(map_fd); - return 0; + free(links); + return error; } diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c index 356171bc392b..5f64ff524cc3 100644 --- a/samples/bpf/trace_event_user.c +++ b/samples/bpf/trace_event_user.c @@ -6,22 +6,24 @@ #include #include #include -#include -#include -#include #include #include #include -#include #include #include +#include #include -#include "bpf_load.h" #include "perf-sys.h" #include "trace_helpers.h" +#define __must_check +#include + #define SAMPLE_FREQ 50 +/* counts, stackmap */ +static int map_fd[2]; +struct bpf_program *prog; static bool sys_read_seen, sys_write_seen; static void print_ksym(__u64 addr) @@ -136,23 +138,34 @@ static inline int generate_load(void) static void test_perf_event_all_cpu(struct perf_event_attr *attr) { - int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); - int *pmu_fd = malloc(nr_cpus * sizeof(int)); - int i, error = 0; + int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); + struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *)); + int i, pmu_fd, error = 0; + + if (!links) { + printf("malloc of links failed\n"); + error = 1; + goto err; + } /* system wide perf event, no need to inherit */ attr->inherit = 0; /* open perf_event on all cpus */ for (i = 0; i < nr_cpus; i++) { - pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0); - if (pmu_fd[i] < 0) { + pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0); + if (pmu_fd < 0) { printf("sys_perf_event_open failed\n"); error = 1; goto all_cpu_err; } - assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0); - assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0); + links[i] = bpf_program__attach_perf_event(prog, pmu_fd); + if (IS_ERR(links[i])) { + printf("bpf_program__attach_perf_event failed\n"); + close(pmu_fd); + error = 1; + goto all_cpu_err; + } } if (generate_load() < 0) { @@ -161,18 +174,18 @@ static void test_perf_event_all_cpu(struct perf_event_attr *attr) } print_stacks(); all_cpu_err: - for (i--; i >= 0; i--) { - ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE); - close(pmu_fd[i]); - } - free(pmu_fd); + for (i--; i >= 0; i--) + bpf_link__destroy(links[i]); +err: + free(links); if (error) - int_exit(0); + int_exit(error); } static void test_perf_event_task(struct perf_event_attr *attr) { int pmu_fd, error = 0; + struct bpf_link *link; /* per task perf event, enable inherit so the "dd ..." command can be traced properly. * Enabling inherit will cause bpf_perf_prog_read_time helper failure. @@ -185,8 +198,12 @@ static void test_perf_event_task(struct perf_event_attr *attr) printf("sys_perf_event_open failed\n"); int_exit(0); } - assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0); - assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0); + link = bpf_program__attach_perf_event(prog, pmu_fd); + if (IS_ERR(link)) { + printf("bpf_program__attach_perf_event failed\n"); + close(pmu_fd); + int_exit(0); + } if (generate_load() < 0) { error = 1; @@ -194,10 +211,9 @@ static void test_perf_event_task(struct perf_event_attr *attr) } print_stacks(); err: - ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); - close(pmu_fd); + bpf_link__destroy(link); if (error) - int_exit(0); + int_exit(error); } static void test_bpf_perf_event(void) @@ -282,6 +298,7 @@ static void test_bpf_perf_event(void) int main(int argc, char **argv) { struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_object *obj; char filename[256]; snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); @@ -295,9 +312,29 @@ int main(int argc, char **argv) return 1; } - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 2; + obj = bpf_object__open_file(filename, NULL); + if (IS_ERR(obj)) { + printf("opening BPF object file failed\n"); + return 1; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (!prog) { + printf("finding a prog in obj file failed\n"); + return 1; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + printf("loading BPF object file failed\n"); + return 1; + } + + map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts"); + map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap"); + if (map_fd[0] < 0 || map_fd[1] < 0) { + printf("finding a counts/stackmap map in obj file failed\n"); + return 1; } if (fork() == 0) { -- 2.25.1