Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754536AbaAJAmh (ORCPT ); Thu, 9 Jan 2014 19:42:37 -0500 Received: from mail-ea0-f175.google.com ([209.85.215.175]:53496 "EHLO mail-ea0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751929AbaAJAmf (ORCPT ); Thu, 9 Jan 2014 19:42:35 -0500 MIME-Version: 1.0 In-Reply-To: <20140109225815.GI11594@pd.tnic> References: <52C0C9F4.50101@zytor.com> <52C196C3.1040300@halfdog.net> <52C31027.2030101@zytor.com> <20131231192106.GA22535@phenom.dumpdata.com> <52C347F0.8070902@zytor.com> <52CD022E.9040107@halfdog.net> <52CD8E10.3010204@zytor.com> <20140108193655.GD5098@pd.tnic> <52CDC316.4050503@halfdog.net> <52CDD3AE.4030301@zytor.com> <20140109225815.GI11594@pd.tnic> Date: Fri, 10 Jan 2014 08:42:33 +0800 X-Google-Sender-Auth: m3Ew6sk1YIyTMVjb-g12BQ-O_cQ Message-ID: Subject: Re: Sanitize CPU-state when switching tasks (was sanitize CPU-state when switching from virtual-8086 mode to other task) From: Linus Torvalds To: Borislav Petkov Cc: "H. Peter Anvin" , halfdog , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , "the arch/x86 maintainers" , Linux Kernel Mailing List , Ben Hutchings Content-Type: multipart/mixed; boundary=001a11c290de767d9904ef9300e4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --001a11c290de767d9904ef9300e4 Content-Type: text/plain; charset=UTF-8 On Fri, Jan 10, 2014 at 6:58 AM, Borislav Petkov wrote: > > Ok, I was able to reproduce Looking at this, I think this is just a bug in our restore_fpu_checking() hackery for X86_FEATURE_FXSAVE_LEAK.. Which also explains why it only triggers on E-350 - it's only relevant for those K7/K8 CPU's that use this. Maybe just add a fcnlex to before the emms? Something like this (TOTALLY UNTESTED!!) attached patch. Linus --001a11c290de767d9904ef9300e4 Content-Type: text/plain; charset=US-ASCII; name="patch.diff" Content-Disposition: attachment; filename="patch.diff" Content-Transfer-Encoding: base64 X-Attachment-Id: f_hq8pxcn00 IGFyY2gveDg2L2luY2x1ZGUvYXNtL2ZwdS1pbnRlcm5hbC5oIHwgMTMgKysrKysrKy0tLS0tLQog MSBmaWxlIGNoYW5nZWQsIDcgaW5zZXJ0aW9ucygrKSwgNiBkZWxldGlvbnMoLSkKCmRpZmYgLS1n aXQgYS9hcmNoL3g4Ni9pbmNsdWRlL2FzbS9mcHUtaW50ZXJuYWwuaCBiL2FyY2gveDg2L2luY2x1 ZGUvYXNtL2ZwdS1pbnRlcm5hbC5oCmluZGV4IGM0OWE2MTNjNjQ1Mi4uY2VhMWM3NmQ0OWJmIDEw MDY0NAotLS0gYS9hcmNoL3g4Ni9pbmNsdWRlL2FzbS9mcHUtaW50ZXJuYWwuaAorKysgYi9hcmNo L3g4Ni9pbmNsdWRlL2FzbS9mcHUtaW50ZXJuYWwuaApAQCAtMjkzLDEyICsyOTMsMTMgQEAgc3Rh dGljIGlubGluZSBpbnQgcmVzdG9yZV9mcHVfY2hlY2tpbmcoc3RydWN0IHRhc2tfc3RydWN0ICp0 c2spCiAJLyogQU1EIEs3L0s4IENQVXMgZG9uJ3Qgc2F2ZS9yZXN0b3JlIEZEUC9GSVAvRk9QIHVu bGVzcyBhbiBleGNlcHRpb24KIAkgICBpcyBwZW5kaW5nLiAgQ2xlYXIgdGhlIHg4NyBzdGF0ZSBo ZXJlIGJ5IHNldHRpbmcgaXQgdG8gZml4ZWQKIAkgICB2YWx1ZXMuICJtIiBpcyBhIHJhbmRvbSB2 YXJpYWJsZSB0aGF0IHNob3VsZCBiZSBpbiBMMSAqLwotCWFsdGVybmF0aXZlX2lucHV0KAotCQlB U01fTk9QOCBBU01fTk9QMiwKLQkJImVtbXNcblx0IgkJLyogY2xlYXIgc3RhY2sgdGFncyAqLwot CQkiZmlsZGwgJVBbYWRkcl0iLAkvKiBzZXQgRj9QIHRvIGRlZmluZWQgdmFsdWUgKi8KLQkJWDg2 X0ZFQVRVUkVfRlhTQVZFX0xFQUssCi0JCVthZGRyXSAibSIgKHRzay0+dGhyZWFkLmZwdS5oYXNf ZnB1KSk7CisJaWYgKHVubGlrZWx5KHN0YXRpY19jcHVfaGFzKFg4Nl9GRUFUVVJFX0ZYU0FWRV9M RUFLKSkpIHsKKwkJYXNtIHZvbGF0aWxlKAorCQkJImZuY2xleFxuXHQiCisJCQkiZW1tc1xuXHQi CisJCQkiZmlsZGwgJVBbYWRkcl0iCS8qIHNldCBGP1AgdG8gZGVmaW5lZCB2YWx1ZSAqLworCQkJ OiA6IFthZGRyXSAibSIgKHRzay0+dGhyZWFkLmZwdS5oYXNfZnB1KSk7CisJfQogCiAJcmV0dXJu IGZwdV9yZXN0b3JlX2NoZWNraW5nKCZ0c2stPnRocmVhZC5mcHUpOwogfQo= --001a11c290de767d9904ef9300e4-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/