From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1874556-1527163331-2-8666964808768788099 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1527163330; b=RQdU1D7IK65DOWz8pRlrA68JycWc+gfRO1A5v/ZPJ3TPeAsaAG myXceIeJdFopw/gzYEY4g5xVW9RAKasFOhtbvLOQyqcXb43N8FX4onjSED4dAbek XxgfLbMTAs0QCiwNGMaT/Puv1blkfaa5zvrawuRvYBWEU69SPztejCzLloJBFAHp dIrFZsYibQzSLbu/QzsiHC/ifH5ICtJSYBdKdGtht5aD178azDkMNQ7Q/f86hNGY tNoCO/ZM5Kxs4x72GDxpSx2U6aMr38UoRR8M59Rx9zqUG1HkSwdPdRl4P2dCBbc+ LQrX7aQ1ExgkGTLSg6qzAhtoNheZgJx8Hy2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=fm2; t=1527163330; bh=WrCrO6LpLPMKD+ZtlUiuKe/3MuHRLW aHrp8DtDgcrM0=; b=VQWOOShLMsg5E630sDXoPPaeLlACewE8nBUMqRkqbPsjMe 3/jdnpqdEc3zTlhxxevOC/WHf6VcvQDfxSEU7EHY1jayBkfS6XlnyR/Z3PZQVwYy pcm9USkyifltR/CFn13ckHp8Q/L3airUDJGBXzquFPxqV6tFqvtq3ZWNvs2E7o3b edQpLO/gFQhbRK0AR/OnDM/Ds2BInckuz6OaFLWKbQecNxvCaY0H1nC+0juxSAne 9/3yv9Jn1lt/FcJApZuFkCiiYy8P0RFltZOjJyRY29AFKkvDWR9gt+3QAsrLiEgO YaCyxSkeKKVe8T1KJYn2pT+uRzCkNLmaVV4FO/Og== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=ngfDPH8m x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=default; dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=ngfDPH8m x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=default; dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfDu0LYUGQV3jngSBo0V2pnliX11sFCOKunoBIHYFiAZkQwruqOYWZ8HoHhvw/TPiv7O35R0ByPqsb0Wrwj/LhJPpfgq3mLKRCMeaTxTScAgkZxn3JpWJ xT2LT6RPlOiAl+cSZTzcfe/+fFb29ksM3zS93JICydg7iwNCdT4qVwRRnixKTKumMtmK+6D7StHqyPjLpbfa4aekKaZtNm+FhuvkauFfkvbSybwM+i8kUs+k X-CM-Analysis: v=2.3 cv=E8HjW5Vl c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=VUJBJC2UJ8kA:10 a=meVymXHHAAAA:8 a=VwQbUJbxAAAA:8 a=iox4zFpeAAAA:8 a=ag1SF4gXAAAA:8 a=XRH7TU2YvASs1ZvYd64A:9 a=QEXdDO2ut3YA:10 a=2JgSa4NbpEOStq-L5dxp:22 a=AjGcO6oz07-iQ99wixmX:22 a=WzC6qhA0u3u7Ye7llzcV:22 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966744AbeEXMCE (ORCPT ); Thu, 24 May 2018 08:02:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:56108 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966367AbeEXJoy (ORCPT ); Thu, 24 May 2018 05:44:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Juergen Gross , "Steven Rostedt (VMware)" Subject: [PATCH 4.4 53/92] tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all} Date: Thu, 24 May 2018 11:38:30 +0200 Message-Id: <20180524093204.465524453@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180524093159.286472249@linuxfoundation.org> References: <20180524093159.286472249@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (VMware) commit 45dd9b0666a162f8e4be76096716670cf1741f0e upstream. Doing an audit of trace events, I discovered two trace events in the xen subsystem that use a hack to create zero data size trace events. This is not what trace events are for. Trace events add memory footprint overhead, and if all you need to do is see if a function is hit or not, simply make that function noinline and use function tracer filtering. Worse yet, the hack used was: __array(char, x, 0) Which creates a static string of zero in length. There's assumptions about such constructs in ftrace that this is a dynamic string that is nul terminated. This is not the case with these tracepoints and can cause problems in various parts of ftrace. Nuke the trace events! Link: http://lkml.kernel.org/r/20180509144605.5a220327@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 95a7d76897c1e ("xen/mmu: Use Xen specific TLB flush instead of the generic one.") Reviewed-by: Juergen Gross Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- arch/x86/xen/mmu.c | 4 ---- include/trace/events/xen.h | 16 ---------------- 2 files changed, 20 deletions(-) --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -1316,8 +1316,6 @@ void xen_flush_tlb_all(void) struct mmuext_op *op; struct multicall_space mcs; - trace_xen_mmu_flush_tlb_all(0); - preempt_disable(); mcs = xen_mc_entry(sizeof(*op)); @@ -1335,8 +1333,6 @@ static void xen_flush_tlb(void) struct mmuext_op *op; struct multicall_space mcs; - trace_xen_mmu_flush_tlb(0); - preempt_disable(); mcs = xen_mc_entry(sizeof(*op)); --- a/include/trace/events/xen.h +++ b/include/trace/events/xen.h @@ -377,22 +377,6 @@ DECLARE_EVENT_CLASS(xen_mmu_pgd, DEFINE_XEN_MMU_PGD_EVENT(xen_mmu_pgd_pin); DEFINE_XEN_MMU_PGD_EVENT(xen_mmu_pgd_unpin); -TRACE_EVENT(xen_mmu_flush_tlb_all, - TP_PROTO(int x), - TP_ARGS(x), - TP_STRUCT__entry(__array(char, x, 0)), - TP_fast_assign((void)x), - TP_printk("%s", "") - ); - -TRACE_EVENT(xen_mmu_flush_tlb, - TP_PROTO(int x), - TP_ARGS(x), - TP_STRUCT__entry(__array(char, x, 0)), - TP_fast_assign((void)x), - TP_printk("%s", "") - ); - TRACE_EVENT(xen_mmu_flush_tlb_single, TP_PROTO(unsigned long addr), TP_ARGS(addr),