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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 BF35DC282DA for ; Mon, 15 Apr 2019 19:05:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D8F92087C for ; Mon, 15 Apr 2019 19:05:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355102; bh=mF2BBxg4kqXaj9f2hI7ltrvsQ2w8gbMjYgy+7a7ZDXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N2wNO/aaUJ8VeKtikGNYjAsHlUVCgJ4QyKtwXoYnDLqiexXXK5CgyJUriz0x1west yBUdR7jEjZ1A+PrCPxIN6msHjXPe7wiLojvA69vKtnFl4JZARhNJ6IRyiGCzBe1w54 dTRB2lgBufXuxScyb80aKxhJDwiLydltaTQ4YxRU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728571AbfDOTFB (ORCPT ); Mon, 15 Apr 2019 15:05:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:38434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729640AbfDOTFB (ORCPT ); Mon, 15 Apr 2019 15:05:01 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 24357218A1; Mon, 15 Apr 2019 19:04:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355100; bh=mF2BBxg4kqXaj9f2hI7ltrvsQ2w8gbMjYgy+7a7ZDXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q7DcZdj3PjWL4T2yXwjh+2Rwo1ntPaI3c1g3w+I5KOEckgcYLAZyKi/LBBYs+kSY/ iwTekA+vOlO0Hl8HJXEIanJsqinyO38T/LBmqtcUgE8wxt2iQO8VDSHYlMhr5AUbbl SVEVjSraVMc08p8IzoInyxWSnWf6WEbcGbnJ4s2g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Biedl , Breno Leitao , Michael Ellerman , Michael Neuling , Sasha Levin Subject: [PATCH 4.19 003/101] powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM Date: Mon, 15 Apr 2019 20:58:01 +0200 Message-Id: <20190415183740.520791587@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183740.341577907@linuxfoundation.org> References: <20190415183740.341577907@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 897bc3df8c5aebb54c32d831f917592e873d0559 upstream. Commit e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint") moved a code block around and this block uses a 'msr' variable outside of the CONFIG_PPC_TRANSACTIONAL_MEM, however the 'msr' variable is declared inside a CONFIG_PPC_TRANSACTIONAL_MEM block, causing a possible error when CONFIG_PPC_TRANSACTION_MEM is not defined. error: 'msr' undeclared (first use in this function) This is not causing a compilation error in the mainline kernel, because 'msr' is being used as an argument of MSR_TM_ACTIVE(), which is defined as the following when CONFIG_PPC_TRANSACTIONAL_MEM is *not* set: #define MSR_TM_ACTIVE(x) 0 This patch just fixes this issue avoiding the 'msr' variable usage outside the CONFIG_PPC_TRANSACTIONAL_MEM block, avoiding trusting in the MSR_TM_ACTIVE() definition. Cc: stable@vger.kernel.org Reported-by: Christoph Biedl Fixes: e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint") Signed-off-by: Breno Leitao Signed-off-by: Michael Ellerman Signed-off-by: Michael Neuling Signed-off-by: Sasha Levin --- arch/powerpc/kernel/signal_64.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index bbd1c73243d7..14b0f5b6a373 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -755,12 +755,25 @@ SYSCALL_DEFINE0(rt_sigreturn) if (restore_tm_sigcontexts(current, &uc->uc_mcontext, &uc_transact->uc_mcontext)) goto badframe; - } - else - /* Fall through, for non-TM restore */ + } else #endif - if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) - goto badframe; + { + /* + * Fall through, for non-TM restore + * + * Unset MSR[TS] on the thread regs since MSR from user + * context does not have MSR active, and recheckpoint was + * not called since restore_tm_sigcontexts() was not called + * also. + * + * If not unsetting it, the code can RFID to userspace with + * MSR[TS] set, but without CPU in the proper state, + * causing a TM bad thing. + */ + current->thread.regs->msr &= ~MSR_TS_MASK; + if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) + goto badframe; + } if (restore_altstack(&uc->uc_stack)) goto badframe; -- 2.19.1