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=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 F3FF1C04EB8 for ; Wed, 12 Dec 2018 12:06:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA2A320879 for ; Wed, 12 Dec 2018 12:06:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="o96bmAUR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA2A320879 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727410AbeLLMGn (ORCPT ); Wed, 12 Dec 2018 07:06:43 -0500 Received: from merlin.infradead.org ([205.233.59.134]:58362 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727067AbeLLMGm (ORCPT ); Wed, 12 Dec 2018 07:06:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=KE0Uju2EMJOC0Ptn9MvAloDfVA2Vqan93O5UwJjfey0=; b=o96bmAURhLugHIhEhZ+ahhCoy g/6GRTbJ/F5OE8BlNy/ZILDpjVVe7ZqyMOXp80cjq29zYG0xxVaPltpiBopdExsNJpKuSseinO9Fd oSRKsztgz0BTZ2rpAZHpoMaSv/WUdvlGao8UTeHL8RD8yWscayQctg4RbjiRsCaz3LJBCcIgygF9C sMw70C0ZRYqXO4p9L3ys8DhOffXziRCmHXNj2qfXGddWiKZyA/CATnoWm7otWUOT2V6LNgn+nnFES pXwCAutDtbTjMxajUZxYn1j93c0A+C7y7Nc6QwH4PXaARg+HI8OuVMgNpxz45dI4TgYuQPYLpt9bC LyiF9Fz/w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gX3Hf-0007iV-Jg; Wed, 12 Dec 2018 12:06:35 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 031992075BD0D; Wed, 12 Dec 2018 13:06:32 +0100 (CET) Date: Wed, 12 Dec 2018 13:06:32 +0100 From: Peter Zijlstra To: Song Liu Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, kernel-team@fb.com, acme@kernel.org Subject: Re: [PATCH v3 perf, bpf-next 1/4] perf, bpf: Introduce PERF_RECORD_BPF_EVENT Message-ID: <20181212120632.GY5289@hirez.programming.kicks-ass.net> References: <20181211233351.4036381-1-songliubraving@fb.com> <20181211233351.4036381-2-songliubraving@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181211233351.4036381-2-songliubraving@fb.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 11, 2018 at 03:33:47PM -0800, Song Liu wrote: > +static void perf_event_bpf_output(struct perf_event *event, > + void *data) > +{ > + struct perf_bpf_event *bpf_event = data; > + struct perf_output_handle handle; > + struct perf_sample_data sample; > + char name[KSYM_NAME_LEN]; > + int name_len; > + int ret; > + > + if (!perf_event_bpf_match(event)) > + return; > + > + /* get prog name and round up to 64 bit aligned */ > + bpf_get_prog_name(bpf_event->prog, name); > + name_len = strlen(name) + 1; > + while (!IS_ALIGNED(name_len, sizeof(u64))) > + name[name_len++] = '\0'; Does this not require something like: BUILD_BUG_ON(KSYM_NAME_LEN % sizeof(u64));