From patchwork Wed Dec 1 18:25:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beau Belgrave X-Patchwork-Id: 12650743 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32309C433F5 for ; Wed, 1 Dec 2021 18:25:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229547AbhLAS2n (ORCPT ); Wed, 1 Dec 2021 13:28:43 -0500 Received: from linux.microsoft.com ([13.77.154.182]:48018 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352370AbhLAS2l (ORCPT ); Wed, 1 Dec 2021 13:28:41 -0500 Received: from localhost.localdomain (c-73-140-2-214.hsd1.wa.comcast.net [73.140.2.214]) by linux.microsoft.com (Postfix) with ESMTPSA id 40ECA20E5817; Wed, 1 Dec 2021 10:25:20 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 40ECA20E5817 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1638383120; bh=wzV6gNPzbresSOz0x+IMa87evygVUZ/A81N4s6+ijpA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fa40V8EbSnw7z/LKpdN7mwLDCUHjlENJepkkKndYmuQzNSvtVM2YccvcBqeTfVqzc AAi+jsfY2nypzTw0KOkjHwy7Vz/NACZWTWZqBDww4Hh+WAbghmeqS6+Sj+N5TIQVBe Ae8RUit49faF1pxHwTSAQmzAcmcJBXlq86JtjhCE= From: Beau Belgrave To: rostedt@goodmis.org, mhiramat@kernel.org Cc: linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org, beaub@linux.microsoft.com Subject: [PATCH v6 05/13] user_events: Add basic perf and eBPF support Date: Wed, 1 Dec 2021 10:25:07 -0800 Message-Id: <20211201182515.2446-6-beaub@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211201182515.2446-1-beaub@linux.microsoft.com> References: <20211201182515.2446-1-beaub@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org Adds support to write out user_event data to perf_probe/perf files as well as to any attached eBPF program. Signed-off-by: Beau Belgrave --- kernel/trace/trace_events_user.c | 63 ++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index 04d72e491d02..9978cebf2a00 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -541,6 +541,50 @@ static void user_event_ftrace(struct user_event *user, void *data, u32 datalen, trace_event_buffer_commit(&event_buffer); } +#ifdef CONFIG_PERF_EVENTS +/* + * Writes the user supplied payload out to perf ring buffer or eBPF program. + */ +static void user_event_perf(struct user_event *user, void *data, u32 datalen, + void *tpdata) +{ + struct hlist_head *perf_head; + + if (bpf_prog_array_valid(&user->call)) { + struct user_bpf_context context = {0}; + + context.data_len = datalen; + context.data_type = USER_BPF_DATA_KERNEL; + context.kdata = data; + + trace_call_bpf(&user->call, &context); + } + + perf_head = this_cpu_ptr(user->call.perf_events); + + if (perf_head && !hlist_empty(perf_head)) { + struct trace_entry *perf_entry; + struct pt_regs *regs; + size_t size = sizeof(*perf_entry) + datalen; + int context; + + perf_entry = perf_trace_buf_alloc(ALIGN(size, 8), + ®s, &context); + + if (unlikely(!perf_entry)) + return; + + perf_fetch_caller_regs(regs); + + memcpy(perf_entry + 1, data, datalen); + + perf_trace_buf_submit(perf_entry, size, context, + user->call.event.type, 1, regs, + perf_head, NULL); + } +} +#endif + /* * Update the register page that is shared between user processes. */ @@ -563,6 +607,10 @@ static void update_reg_page_for(struct user_event *user) if (probe_func == user_event_ftrace) status |= EVENT_STATUS_FTRACE; +#ifdef CONFIG_PERF_EVENTS + else if (probe_func == user_event_perf) + status |= EVENT_STATUS_PERF; +#endif else status |= EVENT_STATUS_OTHER; } while ((++probe_func_ptr)->func); @@ -604,7 +652,19 @@ static int user_event_reg(struct trace_event_call *call, #ifdef CONFIG_PERF_EVENTS case TRACE_REG_PERF_REGISTER: + ret = tracepoint_probe_register(call->tp, + call->class->perf_probe, + data); + if (!ret) + goto inc; + break; + case TRACE_REG_PERF_UNREGISTER: + tracepoint_probe_unregister(call->tp, + call->class->perf_probe, + data); + goto dec; + case TRACE_REG_PERF_OPEN: case TRACE_REG_PERF_CLOSE: case TRACE_REG_PERF_ADD: @@ -862,6 +922,9 @@ static int user_event_parse(char *name, char *args, char *flags, user->class.get_fields = user_event_get_fields; user->class.reg = user_event_reg; user->class.probe = user_event_ftrace; +#ifdef CONFIG_PERF_EVENTS + user->class.perf_probe = user_event_perf; +#endif mutex_lock(&event_mutex); ret = user_event_trace_register(user);