From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-564561-1519835417-2-14412990368578377379 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 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='uk', 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=arctest; t=1519835415; b=Zk+bwCT0Adjsb6NNl6dtJVhVJCVknThlnz5loRlKiEbtDnE pi0WECLVzL7nUOknysIjkrSo+oARt4/XNYoIoa/VyqKz4pwilSewp7uL0jprg08M D1bZBrvvAzPDMC7dd3Et1TeOMXP20DXWg34M27Btlkuyagr/Gf11FLc2jSO9DWd0 hAHM5c4aGDgAadFMoTQ7Xzsp4dgC5HxQFZOsaSCopPiMbFc6ejrTGHmyhnvJCCob SrQAMXpN+RM6JfP/0YXqggbJ/aO7yb+Pvndr2f3hlaIGbIyPK0LmaLzizlFX6W4V ZxIOlV1HhY53eSKc+agvTDjg+wz6oz8z2Ac7sPA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1519835415; bh=ud4XTHsc1Juhg2zrvLW H1oE6lWQaH1fhpiSgS08ehoo=; b=mWeqURVE/K8VpCRgYn4TvAGkXmz8RYOlUFK ZtqbD9Xc2VJDeGKhVbDs/hzdp51nbfOyeTy5EoTuxaBBDmT7IElBfZlN7ynJJtJF TOVnL/+E4pcrXpUcSwAGAt2fBHXA1U1jA6qV738bbOeXDcKlGk/gmLc1OAvCPA+q w7LmQSXZmS9cG4+/p0F0YiwPlVTHme6kyul0QpR287+NFGIsfuhIPbarcv7ijuk0 TouCSerZwft/3WtqZBJ6sRXeuJFHkGw04EgTnYA90cZIEcxqpcUyJkqwLsM1IF79 boYlpE3S1nHezwg65bZVcNpO2zy3dIntkD45dWEWdjxuccyU7xA== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; 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-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=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; 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-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=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934785AbeB1QPQ (ORCPT ); Wed, 28 Feb 2018 11:15:16 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35163 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934530AbeB1QPN (ORCPT ); Wed, 28 Feb 2018 11:15:13 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Maciej W. Rozycki" , linux-mips@linux-mips.org, "Ralf Baechle" Date: Wed, 28 Feb 2018 15:20:18 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 097/254] MIPS: Always clear FCSR cause bits after emulation In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false 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: 3.16.55-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Maciej W. Rozycki" commit 443c44032a54f9acf027a8e688380fddc809bc19 upstream. Clear any FCSR cause bits recorded in the saved FPU context after emulation in all cases rather than in `do_fpe' only, so that any unmasked IEEE 754 exception left from emulation does not cause a fatal kernel-mode FPE hardware exception with the CTC1 instruction used by the kernel to subsequently restore FCSR hardware from the saved FPU context. Signed-off-by: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9704/ Signed-off-by: Ralf Baechle [bwh: Backported to 3.16: drop changes in mips-r2-to-r6-emul and simulate_fp()] Signed-off-by: Ben Hutchings --- --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -775,7 +775,7 @@ asmlinkage void do_fpe(struct pt_regs *r /* * We can't allow the emulated instruction to leave any of - * the cause bit set in $fcr31. + * the cause bits set in $fcr31. */ current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X; @@ -1292,6 +1292,13 @@ asmlinkage void do_cpu(struct pt_regs *r sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 0, &fault_addr); + + /* + * We can't allow the emulated instruction to leave + * any of the cause bits set in $fcr31. + */ + current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X; + if (!process_fpemu_return(sig, fault_addr) && !err) mt_ase_fp_affinity(); }