[v3,1/8] perf bpf-filter: Make filters map a single entry hashmap

Message ID	20240703223035.2024586-2-namhyung@kernel.org (mailing list archive)
State	Not Applicable
Delegated to:	BPF
Headers	show Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD6D0191F70; Wed, 3 Jul 2024 22:30:37 +0000 (UTC) From: Namhyung Kim <namhyung@kernel.org> To: Arnaldo Carvalho de Melo <acme@kernel.org>, Ian Rogers <irogers@google.com>, Kan Liang <kan.liang@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org>, Adrian Hunter <adrian.hunter@intel.com>, Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>, LKML <linux-kernel@vger.kernel.org>, linux-perf-users@vger.kernel.org, KP Singh <kpsingh@kernel.org>, Song Liu <song@kernel.org>, bpf@vger.kernel.org, Stephane Eranian <eranian@google.com> Subject: [PATCH v3 1/8] perf bpf-filter: Make filters map a single entry hashmap Date: Wed, 3 Jul 2024 15:30:28 -0700 Message-ID: <20240703223035.2024586-2-namhyung@kernel.org> In-Reply-To: <20240703223035.2024586-1-namhyung@kernel.org> References: <20240703223035.2024586-1-namhyung@kernel.org> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	perf record: Use a pinned BPF program for filter \| expand [PATCHSET,v3,0/8] perf record: Use a pinned BPF program for filter [v3,1/8] perf bpf-filter: Make filters map a single entry hashmap [v3,2/8] perf bpf-filter: Pass 'target' to perf_bpf_filter__prepare() [v3,3/8] perf bpf-filter: Split per-task filter use case [v3,4/8] perf bpf-filter: Support pin/unpin BPF object [v3,5/8] perf bpf-filter: Support separate lost counts for each filter [v3,6/8] perf record: Fix a potential error handling issue [v3,7/8] perf record: Add --setup-filter option [v3,8/8] perf test: Update sample filtering test

Context	Check	Description
netdev/tree_selection	success	Not a local patch

diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c index 04f98b6bb291..2510832d83f9 100644 --- a/tools/perf/util/bpf-filter.c +++ b/tools/perf/util/bpf-filter.c @@ -93,71 +93,102 @@ static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr * int perf_bpf_filter__prepare(struct evsel *evsel) { - int i, x, y, fd; + int i, x, y, fd, ret; struct sample_filter_bpf *skel; struct bpf_program *prog; struct bpf_link *link; struct perf_bpf_filter_expr *expr; + struct perf_bpf_filter_entry *entry; + + entry = calloc(MAX_FILTERS, sizeof(*entry)); + if (entry == NULL) + return -1; skel = sample_filter_bpf__open_and_load(); if (!skel) { pr_err("Failed to load perf sample-filter BPF skeleton\n"); - return -1; + ret = -EPERM; + goto err; } i = 0; fd = bpf_map__fd(skel->maps.filters); list_for_each_entry(expr, &evsel->bpf_filters, list) { - struct perf_bpf_filter_entry entry = { - .op = expr->op, - .part = expr->part, - .term = expr->term, - .value = expr->val, - }; + if (check_sample_flags(evsel, expr) < 0) { + ret = -EINVAL; + goto err; + } - if (check_sample_flags(evsel, expr) < 0) - return -1; + if (i == MAX_FILTERS) { + ret = -E2BIG; + goto err; + } - bpf_map_update_elem(fd, &i, &entry, BPF_ANY); + entry[i].op = expr->op; + entry[i].part = expr->part; + entry[i].term = expr->term; + entry[i].value = expr->val; i++; if (expr->op == PBF_OP_GROUP_BEGIN) { struct perf_bpf_filter_expr *group; list_for_each_entry(group, &expr->groups, list) { - struct perf_bpf_filter_entry group_entry = { - .op = group->op, - .part = group->part, - .term = group->term, - .value = group->val, - }; - bpf_map_update_elem(fd, &i, &group_entry, BPF_ANY); + if (i == MAX_FILTERS) { + ret = -E2BIG; + goto err; + } + + entry[i].op = group->op; + entry[i].part = group->part; + entry[i].term = group->term; + entry[i].value = group->val; i++; } - memset(&entry, 0, sizeof(entry)); - entry.op = PBF_OP_GROUP_END; - bpf_map_update_elem(fd, &i, &entry, BPF_ANY); + if (i == MAX_FILTERS) { + ret = -E2BIG; + goto err; + } + + entry[i].op = PBF_OP_GROUP_END; i++; } } - if (i > MAX_FILTERS) { - pr_err("Too many filters: %d (max = %d)\n", i, MAX_FILTERS); - return -1; + if (i < MAX_FILTERS) { + /* to terminate the loop early */ + entry[i].op = PBF_OP_DONE; + i++; + } + + /* The filters map has only one entry for now */ + i = 0; + if (bpf_map_update_elem(fd, &i, entry, BPF_ANY) < 0) { + ret = -errno; + pr_err("Failed to update the filter map\n"); + goto err; } + prog = skel->progs.perf_sample_filter; for (x = 0; x < xyarray__max_x(evsel->core.fd); x++) { for (y = 0; y < xyarray__max_y(evsel->core.fd); y++) { link = bpf_program__attach_perf_event(prog, FD(evsel, x, y)); if (IS_ERR(link)) { pr_err("Failed to attach perf sample-filter program\n"); - return PTR_ERR(link); + ret = PTR_ERR(link); + goto err; } } } + free(entry); evsel->bpf_skel = skel; return 0; + +err: + free(entry); + sample_filter_bpf__destroy(skel); + return ret; } int perf_bpf_filter__destroy(struct evsel *evsel) diff --git a/tools/perf/util/bpf_skel/sample-filter.h b/tools/perf/util/bpf_skel/sample-filter.h index 350efa121026..bb6a1b91f1df 100644 --- a/tools/perf/util/bpf_skel/sample-filter.h +++ b/tools/perf/util/bpf_skel/sample-filter.h @@ -14,6 +14,7 @@ enum perf_bpf_filter_op { PBF_OP_AND, PBF_OP_GROUP_BEGIN, PBF_OP_GROUP_END, + PBF_OP_DONE, }; enum perf_bpf_filter_term { diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c index f59985101973..0d56e52b922c 100644 --- a/tools/perf/util/bpf_skel/sample_filter.bpf.c +++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c @@ -9,10 +9,10 @@ /* BPF map that will be filled by user space */ struct filters { - __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(type, BPF_MAP_TYPE_HASH); __type(key, int); - __type(value, struct perf_bpf_filter_entry); - __uint(max_entries, MAX_FILTERS); + __type(value, struct perf_bpf_filter_entry[MAX_FILTERS]); + __uint(max_entries, 1); } filters SEC(".maps"); int dropped; @@ -179,39 +179,39 @@ int perf_sample_filter(void *ctx) __u64 sample_data; int in_group = 0; int group_result = 0; - int i; + int i, k; kctx = bpf_cast_to_kern_ctx(ctx); - for (i = 0; i < MAX_FILTERS; i++) { - int key = i; /* needed for verifier :( */ + k = 0; + entry = bpf_map_lookup_elem(&filters, &k); + if (entry == NULL) + goto drop; - entry = bpf_map_lookup_elem(&filters, &key); - if (entry == NULL) - break; - sample_data = perf_get_sample(kctx, entry); + for (i = 0; i < MAX_FILTERS; i++) { + sample_data = perf_get_sample(kctx, &entry[i]); - switch (entry->op) { + switch (entry[i].op) { case PBF_OP_EQ: - CHECK_RESULT(sample_data, ==, entry->value) + CHECK_RESULT(sample_data, ==, entry[i].value) break; case PBF_OP_NEQ: - CHECK_RESULT(sample_data, !=, entry->value) + CHECK_RESULT(sample_data, !=, entry[i].value) break; case PBF_OP_GT: - CHECK_RESULT(sample_data, >, entry->value) + CHECK_RESULT(sample_data, >, entry[i].value) break; case PBF_OP_GE: - CHECK_RESULT(sample_data, >=, entry->value) + CHECK_RESULT(sample_data, >=, entry[i].value) break; case PBF_OP_LT: - CHECK_RESULT(sample_data, <, entry->value) + CHECK_RESULT(sample_data, <, entry[i].value) break; case PBF_OP_LE: - CHECK_RESULT(sample_data, <=, entry->value) + CHECK_RESULT(sample_data, <=, entry[i].value) break; case PBF_OP_AND: - CHECK_RESULT(sample_data, &, entry->value) + CHECK_RESULT(sample_data, &, entry[i].value) break; case PBF_OP_GROUP_BEGIN: in_group = 1; @@ -222,6 +222,9 @@ int perf_sample_filter(void *ctx) goto drop; in_group = 0; break; + case PBF_OP_DONE: + /* no failures so far, accept it */ + return 1; } } /* generate sample data */

[v3,1/8] perf bpf-filter: Make filters map a single entry hashmap

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