From patchwork Mon Mar 27 07:58:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13188757 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B78ECC761AF for ; Mon, 27 Mar 2023 08:27:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233351AbjC0I1G (ORCPT ); Mon, 27 Mar 2023 04:27:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233115AbjC0I0W (ORCPT ); Mon, 27 Mar 2023 04:26:22 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F83E5FC3; Mon, 27 Mar 2023 01:24:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679905492; x=1711441492; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qlKMvNMl6phwDM/NFmlFjCkIxGABaABfFRVavP867bI=; b=NEserNeaek6yzaixPJBN4iyfZ8SxQl4y3g9koSN3zMM7T6hpKzGq7t9S xaOhLvE730k/NDbglyFqkXbMrOU8sMNmBKYbnglKrj6EJcNY3YFbTsVuV 5f5agu6r9eJLTHhkigND+//z14gV6i/KTTf2Ssd0nd7aSfGSTrOaxMbPH jvEllAGHG3vqW2XxogesV4HsCA4RmOV/PlRsnsK2mQmKtnZysYpbTjvH2 25twTTMwOIIBEV0MsHiJ+cL/ozOq3cfgU3vGW3HkPW4V9zBbIUS/31YXa 8hjpiA3sZ+EwUeAXjAkSZCgRvBQRzb+XhC823M9p49eH17Wq3V+Nzub3T A==; X-IronPort-AV: E=McAfee;i="6600,9927,10661"; a="338930418" X-IronPort-AV: E=Sophos;i="5.98,294,1673942400"; d="scan'208";a="338930418" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2023 01:24:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10661"; a="713787159" X-IronPort-AV: E=Sophos;i="5.98,294,1673942400"; d="scan'208";a="713787159" Received: from unknown (HELO fred..) ([172.25.112.68]) by orsmga008.jf.intel.com with ESMTP; 27 Mar 2023 01:24:41 -0700 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com, jiangshanlai@gmail.com, shan.kang@intel.com Subject: [PATCH v6 31/33] x86/fred: BUG() when ERETU with %rsp not equal to that when the ring 3 event was just delivered Date: Mon, 27 Mar 2023 00:58:36 -0700 Message-Id: <20230327075838.5403-32-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230327075838.5403-1-xin3.li@intel.com> References: <20230327075838.5403-1-xin3.li@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org A FRED stack frame generated by a ring 3 event should never be messed up, and the first thing we must make sure is that at the time an ERETU instruction is executed, %rsp must have the same address as that when the user level event was just delivered. However we don't want to bother the normal code path of ERETU because it's on the hotest code path, a good choice is to do this check when ERETU faults. Suggested-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/mm/extable.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index a5d75b27a993..bf8005558935 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -204,6 +204,14 @@ static bool ex_handler_eretu(const struct exception_table_entry *fixup, unsigned short ss = uregs->ss; unsigned short cs = uregs->cs; + /* + * A FRED stack frame generated by a ring 3 event should never be + * messed up, and the first thing we must make sure is that at the + * time an ERETU instruction is executed, %rsp must have the same + * address as that when the user level event was just delivered. + */ + BUG_ON(uregs != current->thread_info.user_pt_regs); + /* * Move the NMI bit from the invalid stack frame, which caused ERETU * to fault, to the fault handler's stack frame, thus to unblock NMI