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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 563BAC43461 for ; Wed, 16 Sep 2020 17:44:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14E12206DC for ; Wed, 16 Sep 2020 17:44:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600278277; bh=KHuglKLcKtYICMFeenAq3DvHYF00j0yYiXqdTbisipw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=t1x0xOACBnmB9Vw/3qxgkBqfHU/Ay/0PkNYrECi0oXeGOMtHuQpNbjNRJwfOLZnLo BFqS1CZkfIrJ8T1Iz1Lhlrppp6Z8psqZIGfdOJKpW482AYNk2vJbet98yykr81I4Qn YAcxsxfvmkohqxZl7L9cmmDFPO/sR2zht5QfGUD8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727344AbgIPRof (ORCPT ); Wed, 16 Sep 2020 13:44:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:56298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727335AbgIPRkl (ORCPT ); Wed, 16 Sep 2020 13:40:41 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A0F41223C8; Wed, 16 Sep 2020 14:07:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600265266; bh=KHuglKLcKtYICMFeenAq3DvHYF00j0yYiXqdTbisipw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vVEApFj0yzYYodJ/TmxoXbAwb/XPSO7sOlGGqvPJhLfrTL8aF4+u8zUS6p1CJH9yZ RWhoeXWDewsS4v/5zeyrCUoCgHR8NdcSRt3e3jvcBmq/5EUpsz7cUIqfABe3PSGdty eKpM/Xk3+JMnrUt5KlW3OQpaHyfUm/bWkXE9drew= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id B4666400E9; Wed, 16 Sep 2020 11:07:44 -0300 (-03) Date: Wed, 16 Sep 2020 11:07:44 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Ian Rogers , Jiri Olsa , lkml , Peter Zijlstra , Ingo Molnar , Mark Rutland , Namhyung Kim , Alexander Shishkin , Michael Petlan , Song Liu , "Frank Ch. Eigler" , Stephane Eranian , Alexey Budankov , Andi Kleen , Adrian Hunter Subject: Re: [PATCH 16/26] perf tools: Synthesize modules with mmap3 Message-ID: <20200916140744.GR720847@kernel.org> References: <20200913210313.1985612-1-jolsa@kernel.org> <20200913210313.1985612-17-jolsa@kernel.org> <20200914160758.GK160517@kernel.org> <20200916082018.GA2301783@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200916082018.GA2301783@krava> X-Url: http://acmel.wordpress.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Wed, Sep 16, 2020 at 10:20:18AM +0200, Jiri Olsa escreveu: > On Tue, Sep 15, 2020 at 01:17:44PM -0700, Ian Rogers wrote: > > SNIP > > > > > /* > > > > * kernel uses 0 for user space maps, see kernel/perf_event.c > > > > * __perf_event_mmap > > > > @@ -631,17 +629,30 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t > > > > continue; > > > > > > > > size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64)); > > > > - event->mmap.header.type = PERF_RECORD_MMAP; > > > > - event->mmap.header.size = (sizeof(event->mmap) - > > > > - (sizeof(event->mmap.filename) - size)); > > > > - memset(event->mmap.filename + size, 0, machine->id_hdr_size); > > > > - event->mmap.header.size += machine->id_hdr_size; > > > > - event->mmap.start = pos->start; > > > > - event->mmap.len = pos->end - pos->start; > > > > - event->mmap.pid = machine->pid; > > > > - > > > > - memcpy(event->mmap.filename, pos->dso->long_name, > > > > + event->mmap3.header.type = PERF_RECORD_MMAP3; > > > > + event->mmap3.header.size = (sizeof(event->mmap3) - > > > > + (sizeof(event->mmap3.filename) - size)); > > > > + memset(event->mmap3.filename + size, 0, machine->id_hdr_size); > > > > + event->mmap3.header.size += machine->id_hdr_size; > > > > + event->mmap3.start = pos->start; > > > > + event->mmap3.len = pos->end - pos->start; > > > > + event->mmap3.pid = machine->pid; > > > > + > > > > + memcpy(event->mmap3.filename, pos->dso->long_name, > > > > pos->dso->long_name_len + 1); > > > > + > > > > + rc = filename__read_build_id(event->mmap3.filename, event->mmap3.buildid, > > > > + BUILD_ID_SIZE); > > > > + if (rc != BUILD_ID_SIZE) { > > > > IIRC BUILD_ID_SIZE is 20 bytes which is the correct size for SHA-1. A > > build ID may be 128-bits (16 bytes) if md5 or uuid hashes are used. > > Should this test just be "> 0" ? > > ah right, will check on that And how do you deal with this in the kernel? I.e. to inform userspace, via the PERF_RECORD_MMAP3 (or MMAP2 with that misc bit trick) the size of the build-id? - Arnaldo