From patchwork Wed Jul 5 18:12:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Valentin Schneider X-Patchwork-Id: 13302557 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 D9C75134A7 for ; Wed, 5 Jul 2023 18:15:57 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9326019A1 for ; Wed, 5 Jul 2023 11:15:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688580955; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EWVIdw42kvaUEVB9fypVLDqQXfw7FfQjjY+1yjJwfjg=; b=FnKs0PdDgbjFf1FMZNWkI5dda48M2XYMm35ApvBNjyYUcx22JkBNXWCGib9Ac6YKtzlcaB eEZpDo0IezqoxUGoNre1364UzXVosZhnown6hLt5batZ5NqX8NdqBEcryiA89UCrsAJdM1 QX6+DHsh5r8skSFxdyjPuhrzhhcQrow= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-615-gN3SJfgUNXa5eGtNW0oHxQ-1; Wed, 05 Jul 2023 14:15:51 -0400 X-MC-Unique: gN3SJfgUNXa5eGtNW0oHxQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 87DBC2808E6A; Wed, 5 Jul 2023 18:15:49 +0000 (UTC) Received: from vschneid.remote.csb (unknown [10.42.28.164]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8CD04F5CFA; Wed, 5 Jul 2023 18:15:44 +0000 (UTC) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, x86@kernel.org Cc: Steven Rostedt , Masami Hiramatsu , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Andy Lutomirski , Peter Zijlstra , Frederic Weisbecker , "Paul E. McKenney" , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Josh Poimboeuf , Kees Cook , Sami Tolvanen , Ard Biesheuvel , Nicholas Piggin , Juerg Haefliger , Nicolas Saenz Julienne , "Kirill A. Shutemov" , Nadav Amit , Dan Carpenter , Chuang Wang , Yang Jihong , Petr Mladek , "Jason A. Donenfeld" , Song Liu , Julian Pidancet , Tom Lendacky , Dionna Glaze , =?utf-8?q?Thomas_Wei=C3=9Fschuh?= , Juri Lelli , Daniel Bristot de Oliveira , Marcelo Tosatti , Yair Podemsky Subject: [RFC PATCH 02/14] tracing/filters: Enable filtering a cpumask field by another cpumask Date: Wed, 5 Jul 2023 19:12:44 +0100 Message-Id: <20230705181256.3539027-3-vschneid@redhat.com> In-Reply-To: <20230705181256.3539027-1-vschneid@redhat.com> References: <20230705181256.3539027-1-vschneid@redhat.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-State: RFC The recently introduced ipi_send_cpumask trace event contains a cpumask field, but it currently cannot be used in filter expressions. Make event filtering aware of cpumask fields, and allow these to be filtered by a user-provided cpumask. The user-provided cpumask is to be given in cpulist format and wrapped as: "MASK{$cpulist}". The use of curly braces instead of parentheses is to prevent predicate_parse() from parsing the contents of MASK{...} as a full-fledged predicate subexpression. This enables e.g.: $ trace-cmd record -e 'ipi_send_cpumask' -f 'cpu & MASK{2,4,6,8-32}' Signed-off-by: Valentin Schneider --- include/linux/trace_events.h | 1 + kernel/trace/trace_events_filter.c | 85 +++++++++++++++++++++++++++++- 2 files changed, 84 insertions(+), 2 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 7c4a0b72334eb..974ef37a06c83 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -804,6 +804,7 @@ enum { FILTER_RDYN_STRING, FILTER_PTR_STRING, FILTER_TRACE_FN, + FILTER_CPUMASK, FILTER_COMM, FILTER_CPU, FILTER_STACKTRACE, diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index d999a218fe833..8af00caa363f7 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -64,6 +64,7 @@ enum filter_pred_fn { FILTER_PRED_FN_PCHAR_USER, FILTER_PRED_FN_PCHAR, FILTER_PRED_FN_CPU, + FILTER_PRED_FN_CPUMASK, FILTER_PRED_FN_FUNCTION, FILTER_PRED_FN_, FILTER_PRED_TEST_VISITED, @@ -71,6 +72,7 @@ enum filter_pred_fn { struct filter_pred { struct regex *regex; + struct cpumask *mask; unsigned short *ops; struct ftrace_event_field *field; u64 val; @@ -94,6 +96,8 @@ struct filter_pred { C(TOO_MANY_OPEN, "Too many '('"), \ C(TOO_MANY_CLOSE, "Too few '('"), \ C(MISSING_QUOTE, "Missing matching quote"), \ + C(MISSING_BRACE_OPEN, "Missing '{'"), \ + C(MISSING_BRACE_CLOSE, "Missing '}'"), \ C(OPERAND_TOO_LONG, "Operand too long"), \ C(EXPECT_STRING, "Expecting string field"), \ C(EXPECT_DIGIT, "Expecting numeric field"), \ @@ -103,6 +107,7 @@ struct filter_pred { C(BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \ C(TOO_MANY_PREDS, "Too many terms in predicate expression"), \ C(INVALID_FILTER, "Meaningless filter expression"), \ + C(INVALID_CPULIST, "Invalid cpulist"), \ C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \ C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), \ C(NO_FUNCTION, "Function not found"), \ @@ -189,6 +194,7 @@ enum { static void free_predicate(struct filter_pred *pred) { kfree(pred->regex); + kfree(pred->mask); kfree(pred); } @@ -875,6 +881,26 @@ static int filter_pred_cpu(struct filter_pred *pred, void *event) } } +/* Filter predicate for cpumasks. */ +static int filter_pred_cpumask(struct filter_pred *pred, void *event) +{ + u32 item = *(u32 *)(event + pred->offset); + int loc = item & 0xffff; + const struct cpumask *mask = (event + loc); + const struct cpumask *cmp = pred->mask; + + switch (pred->op) { + case OP_EQ: + return cpumask_equal(mask, cmp); + case OP_NE: + return !cpumask_equal(mask, cmp); + case OP_BAND: + return cpumask_intersects(mask, cmp); + default: + return 0; + } +} + /* Filter predicate for COMM. */ static int filter_pred_comm(struct filter_pred *pred, void *event) { @@ -1242,8 +1268,12 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir, int filter_assign_type(const char *type) { - if (strstr(type, "__data_loc") && strstr(type, "char")) - return FILTER_DYN_STRING; + if (strstr(type, "__data_loc")) { + if (strstr(type, "char")) + return FILTER_DYN_STRING; + if (strstr(type, "cpumask_t")) + return FILTER_CPUMASK; + } if (strstr(type, "__rel_loc") && strstr(type, "char")) return FILTER_RDYN_STRING; @@ -1355,6 +1385,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event) return filter_pred_pchar(pred, event); case FILTER_PRED_FN_CPU: return filter_pred_cpu(pred, event); + case FILTER_PRED_FN_CPUMASK: + return filter_pred_cpumask(pred, event); case FILTER_PRED_FN_FUNCTION: return filter_pred_function(pred, event); case FILTER_PRED_TEST_VISITED: @@ -1566,6 +1598,55 @@ static int parse_pred(const char *str, void *data, strncpy(pred->regex->pattern, str + s, len); pred->regex->pattern[len] = 0; + } else if (!strncmp(str + i, "MASK", 4)) { + unsigned int maskstart; + char *tmp; + + if (field->filter_type != FILTER_CPUMASK) { + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + goto err_free; + } + + /* Skip MASK */ + i += 4; + if (str[i++] != '{') { + parse_error(pe, FILT_ERR_MISSING_BRACE_OPEN, pos + i); + goto err_free; + } + maskstart = i; + + /* Walk the cpulist until closing } */ + for (; str[i] && str[i] != '}'; i++); + if (str[i] != '}') { + parse_error(pe, FILT_ERR_MISSING_BRACE_CLOSE, pos + i); + goto err_free; + } + + if (maskstart == i) { + parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i); + goto err_free; + } + + /* Copy the cpulist between { and } */ + tmp = kmalloc(i - maskstart + 1, GFP_KERNEL); + strncpy(tmp, str + maskstart, i - maskstart); + tmp[i - maskstart] = '\0'; + + pred->mask = kzalloc(cpumask_size(), GFP_KERNEL); + if (!pred->mask) + goto err_mem; + + /* Now parse it */ + if (cpulist_parse(tmp, pred->mask)) { + parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i); + goto err_free; + } + + /* Move along */ + i++; + if (field->filter_type == FILTER_CPUMASK) + pred->fn_num = FILTER_PRED_FN_CPUMASK; + /* This is either a string, or an integer */ } else if (str[i] == '\'' || str[i] == '"') { char q = str[i];