From patchwork Tue Apr 4 10:27:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13199611 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 6196BC6FD1D for ; Tue, 4 Apr 2023 10:56:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234889AbjDDK4o (ORCPT ); Tue, 4 Apr 2023 06:56:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234976AbjDDK4Y (ORCPT ); Tue, 4 Apr 2023 06:56:24 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 450CD4C23; Tue, 4 Apr 2023 03:54:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680605662; x=1712141662; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YkOYUeaNmXvaQHTm0febRcu8lP7lpU11uM/4zVeP9Zg=; b=F2koYtLcmj6pdNPwVoVYOA/Yzn0hnduoSt1J+EdHbxICoKyVgZjap+ME bP2soDjpaggiEZ5+37lELSwR+3X2XDtwYnDm5yIJ6BZHSIEHsqpwfnqhv PtfhamEq8Zldr9ZyKk/t5qksDn+8RAw7IVG6KBV0LHBKC15/muZEPI6Pt Lwue+5Nh1SlR70TnxzixaghjEOQiTJgXHUCxFYBqv27k9wXO7FCATCDWo gT2aBuo3GNyHEOpTlr576vYVfzSDiR408JdIWHA4xYiPnJ1shLnr/0Dj/ IkA7FBl+K+GAWD2vAHyXZaw6MQZQOmgcdPR4YYAt00BkZ3TLu2jkUVAzj Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10669"; a="330734242" X-IronPort-AV: E=Sophos;i="5.98,317,1673942400"; d="scan'208";a="330734242" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2023 03:53:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10669"; a="775597871" X-IronPort-AV: E=Sophos;i="5.98,317,1673942400"; d="scan'208";a="775597871" Received: from unknown (HELO fred..) ([172.25.112.68]) by FMSMGA003.fm.intel.com with ESMTP; 04 Apr 2023 03:53:06 -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 v7 31/33] x86/fred: BUG() when ERETU with %rsp not equal to that when the ring 3 event was just delivered Date: Tue, 4 Apr 2023 03:27:14 -0700 Message-Id: <20230404102716.1795-32-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230404102716.1795-1-xin3.li@intel.com> References: <20230404102716.1795-1-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 9d82193adf3c..be297d4b137b 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