Received: by 2002:a25:868d:0:0:0:0:0 with SMTP id z13csp1463411ybk; Sun, 10 May 2020 17:57:31 -0700 (PDT) X-Google-Smtp-Source: APiQypJwzB0eIAXatRGQoLBvY6xYWanXVqc43aR/fWjVpcSAStLGLHOiPUSFwwwC9G9Xtwk95pld X-Received: by 2002:aa7:d1c6:: with SMTP id g6mr5299038edp.303.1589158651040; Sun, 10 May 2020 17:57:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1589158651; cv=none; d=google.com; s=arc-20160816; b=RWp8nKZ3OekbC2k2SNyp45Psnfz1rvmIuZWLQQf4qwO9ZGEvv9diRYiymZRiXJgV/A oq7i9QGq9Buk8HGyuj+vS+Crg5w1cuelQRwkFtOoSN/RuL+V4H7Abka5r0YHU2uIZr/s 6zGbSvl6CgHAHOT3ISNDfN9YuRX1oOigadQzG27MEp+wuzrK6QhDJUpwpD6haW1YAVaS mIv5yZ2gVzecgQax6j5QYGkZYtaFdyzS+dnZXN7Bjaeqjy++42Vg975lsjorLDg4oTp4 bRYKxke8yERbzfHORxRL5gWZSITIdb4jL4CS3MplQMmHvdTTH2MpthOquKRUQHABYwyQ +k2g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :ironport-sdr:ironport-sdr; bh=0dIaaArhA/cP+CxCQywa+duGMpXSJlq3Wia2d1GkrFw=; b=uLORqgIuRcvY9hmZ52WhzXqR9mCC1EO+v1P585+EhhGnZ78BGUqjonJUpvz/7+JbHt pFmoNCHqct4TgOKHNhqfQfZRlqM0zO0NQx2AmTHD0ogQtwy6g7F+5sPhx4zpVxnfPyNJ 7LVXwiEBX6Yzeu41P0fhuIhxI/hzQbg+27kZsOh1VOoYs1zN1Vz7LLhKohqOs14cFYZM qdScjcMzQxZh/odkjuaJCrLshaejM7JiSSeDjen+eBsXcBHxiRyv4gqkMKRG9J1KQbQR 7eubyn/IvopVCpzJb+NvfckbiuK97Z5LKHcLYb2h0ZyxNSNArxT049eTa/8HI/1NdxN7 cX0w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id m17si5466393eds.398.2020.05.10.17.57.01; Sun, 10 May 2020 17:57:31 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729376AbgEKAu3 (ORCPT + 99 others); Sun, 10 May 2020 20:50:29 -0400 Received: from mga01.intel.com ([192.55.52.88]:49691 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729095AbgEKAu2 (ORCPT ); Sun, 10 May 2020 20:50:28 -0400 IronPort-SDR: Y2L6yXiv3EE+O9ZJQv8YQ+9IqpsyuvNnSMoDl1S+AyDXlffwn9koFaIuNHx6n0mmLqT8IYEUG+ 7LvpLpbIbaaA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2020 17:50:28 -0700 IronPort-SDR: jBNw3LvyTYq9CTX3yjVAc8sa/ZR6hJ4vMGpoNTS80+685W83DLQYRP9A4zrnt4/ahijke6PhDn VMSo7FveWRgw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,377,1583222400"; d="scan'208";a="463204297" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.21]) by fmsmga006.fm.intel.com with ESMTP; 10 May 2020 17:50:28 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 72A19301C52; Sun, 10 May 2020 17:50:28 -0700 (PDT) Date: Sun, 10 May 2020 17:50:28 -0700 From: Andi Kleen To: Vegard Nossum Cc: Sasha Levin , linux-kernel@vger.kernel.org, tglx@linutronix.de, luto@kernel.org, tony.luck@intel.com, chang.seok.bae@intel.com Subject: Re: [PATCH v10 00/18] Enable FSGSBASE instructions Message-ID: <20200511005028.GA226400@tassilo.jf.intel.com> References: <20200423232207.5797-1-sashal@kernel.org> <5a6a0ef5-4dfc-d0b1-9181-5df4211cfcd9@oracle.com> <20200511004842.GJ3538@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200511004842.GJ3538@tassilo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > So this is a check that checks if you're running in user mode if > you have a debug trap with single step, but somehow it triggered > for a user segment. > > Probably the regs got corrupted. > > Sasha, I suspect you're missing a mov %rsp,%rdi somewhere in the > debug entry path that sets up the regs argument for the C code. ... Ah never mind. Thomas has a better explanation. -Andi