From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1340521-1526937504-2-8314166552757597614 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 0.248, 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= 1526937503; b=jQFfggvmoxKvAxYnQGnxI0FjnkzAcRXgGQS33EugYBzCNaeiWu fVBuAWdcE7jaQo1ogTM+3BGotz3LAvZAIo9NB5VperO2BaDNFO0ASQyw78uQ2Bhe eLBR9XPHqgKOGxQexKcyrxaxrzKDYUl3xV2WMNVjYztchZ1AvIQHr2Kqb9VEsysy A4XngrSSh+m/zwTZZU37aHo/fdGXhMFhjMFpdUCysmXHQSuIx8WqEQQU64e1yKpv wrx6obbVCpICp6vkOGBeILlv0ENvRAl7BnXSSmgmwIWpHEHr7iaCLftvV4bb5iJh RSWi66kKt8EYDEr7a9Kz6TCt25sLSti2GStA== 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=1526937503; bh=U1RfPhFKzf8aetq9SGqGQgCUoLzCNd OeWaz80ZxVVkE=; b=Agk1H5v5diAYPhda5wRLtLZMBdRmdxDTm+GQkKDl2eP2Tk L8eLPleP74uDslMk088Amdd4JtstxJG/PevgcqUQJnQWMVNFmD9XMoSfML6t0SP0 xWn63CLx6bjZXbOpMea7hkJqM1mX78xLFC9XdOhq0VenwrgYXfigosm/fyvRtnQt YPdBVUKMNvflaRjvg7NkU+rGc8vCwrh/aqWf1wJVGhDOFi7FodhuQjNDDrZ2Cx2f +JdlyOQSIpJkvRjDKD/yZDKcLM37q6XkKjE4URb7Tacomp19Sb2WbquKJpTfZ5r5 fgtYP/6L7L73c3aVIE+ZMUAW6uFU716C1mkFm1lw== ARC-Authentication-Results: i=1; mx6.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=1HCef8CW 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: mx6.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=1HCef8CW 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: MS4wfGM6aoPW7FSDsoYpVYxvFM30dzLJHRTNWHjPgwW5CMCkJoi0t19gc5BpIIKyxGcHT4zEybMLczMEKG/dWujfHsYB6AHKLJj4WRrYuQvVRrEKl6MXiyPd FGDNDM96J6O5L/yQCY8m0BhcSvwy8SCvbQGhdsXS7184hH/Z8h7mAQzlSN5lOY+n5M5H0jSsIMZdlSQ6ve6+gaA9NQgNIYJIUJohSwvn+KD2Im2VvarghxCi X-CM-Analysis: v=2.3 cv=FKU1Odgs 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 S1752986AbeEUVSU (ORCPT ); Mon, 21 May 2018 17:18:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:33414 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753409AbeEUVSR (ORCPT ); Mon, 21 May 2018 17:18:17 -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 4.14 16/95] tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all} Date: Mon, 21 May 2018 23:11:06 +0200 Message-Id: <20180521210451.010144485@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180521210447.219380974@linuxfoundation.org> References: <20180521210447.219380974@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: 4.14-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 +--- arch/x86/xen/mmu_pv.c | 4 +--- include/trace/events/xen.h | 16 ---------------- 3 files changed, 2 insertions(+), 22 deletions(-) --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -42,13 +42,11 @@ xmaddr_t arbitrary_virt_to_machine(void } EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine); -static void xen_flush_tlb_all(void) +static noinline 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)); --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -1280,13 +1280,11 @@ unsigned long xen_read_cr2_direct(void) return this_cpu_read(xen_vcpu_info.arch.cr2); } -static void xen_flush_tlb(void) +static noinline 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 @@ -349,22 +349,6 @@ 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_one_user, TP_PROTO(unsigned long addr), TP_ARGS(addr),