Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751796AbbD3Vj5 (ORCPT ); Thu, 30 Apr 2015 17:39:57 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46184 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751483AbbD3Vjz (ORCPT ); Thu, 30 Apr 2015 17:39:55 -0400 Message-ID: <5542A0FB.50707@zytor.com> Date: Thu, 30 Apr 2015 14:39:07 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Borislav Petkov , Linus Torvalds CC: Andy Lutomirski , Andy Lutomirski , X86 ML , Denys Vlasenko , Brian Gerst , Denys Vlasenko , Ingo Molnar , Steven Rostedt , Oleg Nesterov , Frederic Weisbecker , Alexei Starovoitov , Will Drewry , Kees Cook , Linux Kernel Mailing List , Mel Gorman Subject: Re: [PATCH] x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue References: <20150427183854.GG28871@pd.tnic> <20150427185344.GI28871@pd.tnic> <61BCF405-8000-43EB-A6B1-2BF5677E4ADE@zytor.com> <20150427200329.GL28871@pd.tnic> <2F6CA156-F03F-4F49-A6B9-7D1D1E1D805B@zytor.com> <20150428155511.GF19025@pd.tnic> <20150428165807.GI19025@pd.tnic> <20150428183820.GJ19025@pd.tnic> In-Reply-To: <20150428183820.GJ19025@pd.tnic> Content-Type: multipart/mixed; boundary="------------000407020700040500060300" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4086 Lines: 71 This is a multi-part message in MIME format. --------------000407020700040500060300 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit This is the microbenchmark I used. For the record, Intel's intention going forward is that 0F 1F will always be as fast or faster than any other alternative. -hpa --------------000407020700040500060300 Content-Type: text/plain; charset=UTF-8; name="nopltest.c" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="nopltest.c" I2RlZmluZSBfR05VX1NPVVJDRQ0KI2luY2x1ZGUgPHN0ZGlvLmg+DQojaW5jbHVkZSA8c3Rk bGliLmg+DQojaW5jbHVkZSA8dGltZS5oPg0KI2luY2x1ZGUgPHN0ZGJvb2wuaD4NCiNpbmNs dWRlIDxzeXMvdGltZS5oPg0KDQpzdGF0aWMgdm9pZCBub3BfcDYodm9pZCkNCnsNCiAgYXNt IHZvbGF0aWxlKCIucmVwdCAxMDAwXG4iDQoJICAgICAgICIuYnl0ZSAweDBmLDB4MWYsMHg0 NCwweDAwLDB4MDBcbiINCgkgICAgICAgIi5lbmRyIik7DQp9DQoNCnN0YXRpYyB2b2lkIG5v cF9rOCh2b2lkKQ0Kew0KICBhc20gdm9sYXRpbGUoIi5yZXB0IDEwMDBcbiINCgkgICAgICAg Ii5ieXRlIDB4NjYsMHg2NiwweDY2LDB4NjYsMHg5MFxuIg0KCSAgICAgICAiLmVuZHIiKTsN Cn0NCg0Kc3RhdGljIHZvaWQgbm9wX2xlYSh2b2lkKQ0Kew0KI2lmZGVmIF9feDg2XzY0X18N CiAgYXNtIHZvbGF0aWxlKCIucmVwdCAxMDAwXG4iDQoJICAgICAgICIuYnl0ZSAweDQ4LDB4 OGQsMHg3NCwweDI2LDB4MDBcbiINCgkgICAgICAgIi5lbmRyIik7DQojZWxzZQ0KICBhc20g dm9sYXRpbGUoIi5yZXB0IDEwMDBcbiINCgkgICAgICAgIi5ieXRlIDB4M2UsMHg4ZCwweDc0 LDB4MjYsMHgwMFxuIg0KCSAgICAgICAiLmVuZHIiKTsNCiNlbmRpZg0KfQ0KDQpzdGF0aWMg dm9pZCBub3Bfam1wNSh2b2lkKQ0Kew0KICBhc20gdm9sYXRpbGUoIi5yZXB0IDEwMDBcbiIN CgkgICAgICAgIi5ieXRlIDB4ZTksMCwwLDAsMFxuIg0KCSAgICAgICAiLmVuZHIiKTsNCn0N Cg0Kc3RhdGljIHZvaWQgbm9wX2ptcDIodm9pZCkNCnsNCiAgYXNtIHZvbGF0aWxlKCIucmVw dCAxMDAwXG4iDQoJICAgICAgICIuYnl0ZSAweGViLDMsMHg5MCwweDkwLDB4OTBcbiINCgkg ICAgICAgIi5lbmRyIik7DQp9DQoNCnN0YXRpYyB2b2lkIG5vcF94Y2hnKHZvaWQpDQp7DQog IGFzbSB2b2xhdGlsZSgiLnJlcHQgMTAwMFxuIg0KCSAgICAgICAiLmJ5dGUgMHg2NiwweDY2 LDB4NjYsMHg4NywweGMwXG4iDQoJICAgICAgICIuZW5kciIpOw0KfQ0KDQpzdGF0aWMgdm9p ZCBub3BfbW92KHZvaWQpDQp7DQogIGFzbSB2b2xhdGlsZSgiLnJlcHQgMTAwMFxuIg0KCSAg ICAgICAiLmJ5dGUgMHg2NiwweDY2LDB4NjYsMHg4OSwweGMwXG4iDQoJICAgICAgICIuZW5k ciIpOw0KfQ0KDQpzdGF0aWMgdm9pZCBub3BfZmRpc2kodm9pZCkNCnsNCiAgYXNtIHZvbGF0 aWxlKCIucmVwdCAxMDAwXG4iDQoJICAgICAgICIuYnl0ZSAweDY2LDB4NjYsMHg2NiwweGRi LDB4ZTFcbiINCgkgICAgICAgIi5lbmRyIik7DQp9DQogIA0Kc3RhdGljIHZvaWQgbm9wX2Zl bmkodm9pZCkNCnsNCiAgYXNtIHZvbGF0aWxlKCIucmVwdCAxMDAwXG4iDQoJICAgICAgICIu Ynl0ZSAweDY2LDB4NjYsMHg2NiwweGRiLDB4ZTBcbiINCgkgICAgICAgIi5lbmRyIik7DQp9 DQoNCnN0cnVjdCB0ZXN0X2xpc3Qgew0KICBjb25zdCBjaGFyICpuYW1lOw0KICB2b2lkICgq ZnVuYykodm9pZCk7DQp9Ow0KDQpzdGF0aWMgY29uc3Qgc3RydWN0IHRlc3RfbGlzdCB0ZXN0 c1tdID0gew0KICB7ICJQNiBOT1BzIChOT1BMKSIsIG5vcF9wNiB9LA0KICB7ICJLOCBOT1Bz ICg2NiA5MCkiLCBub3BfazggfSwNCiAgeyAiTEVBIiwgbm9wX2xlYSB9LA0KICB7ICJYQ0hH Iiwgbm9wX3hjaGcgfSwNCiAgeyAiTU9WIiwgbm9wX21vdiB9LA0KICB7ICJGRElTSSIsIG5v cF9mZGlzaSB9LA0KICB7ICJGRU5JIiwgbm9wX2ZlbmkgfSwNCiAgeyAiRTkgSk1QIiwgbm9w X2ptcDUgfSwNCiAgeyAiRUIgSk1QIiwgbm9wX2ptcDIgfSwNCiAgeyBOVUxMLCBOVUxMIH0N Cn07DQoNCnN0YXRpYyB2b2lkIGJlbmNobWFyayhjb25zdCBzdHJ1Y3QgdGVzdF9saXN0ICp0 ZXN0LCBib29sIHdhcm11cCkNCnsNCiAgc3RydWN0IHRpbWV2YWwgdHYwLCB0djE7DQogIGlu dCBpOw0KICBjb25zdCBpbnQgcmVwcyA9IDEwMDAwMDsNCiAgdW5zaWduZWQgbG9uZyBsb25n IHVzOw0KICANCiAgZ2V0dGltZW9mZGF5KCZ0djAsIE5VTEwpOw0KICBmb3IgKGkgPSAwOyBp IDwgcmVwczsgaSsrKQ0KICAgIHRlc3QtPmZ1bmMoKTsNCiAgZ2V0dGltZW9mZGF5KCZ0djEs IE5VTEwpOw0KDQogIHVzID0gKHR2MS50dl9zZWMgLSB0djAudHZfc2VjKSAqIDEwMDAwMDBV TEwgKw0KICAgICgoaW50KXR2MS50dl91c2VjIC0gKGludCl0djAudHZfdXNlYyk7DQoNCiAg aWYgKCF3YXJtdXApDQogICAgcHJpbnRmKCIlczogJWQgcmVwZXRpdGlvbnMgYXQgJWxsdSB1 c1xuIiwgdGVzdC0+bmFtZSwgcmVwcywgdXMpOw0KfQ0KDQppbnQgbWFpbih2b2lkKQ0Kew0K ICBjb25zdCBzdHJ1Y3QgdGVzdF9saXN0ICp0ZXN0Ow0KICANCiAgZm9yICh0ZXN0ID0gdGVz dHM7IHRlc3QtPmZ1bmM7IHRlc3QrKykgew0KICAgIGJlbmNobWFyayh0ZXN0LCB0cnVlKTsN CiAgICBiZW5jaG1hcmsodGVzdCwgZmFsc2UpOw0KICB9DQoNCiAgcmV0dXJuIDA7DQp9DQo= --------------000407020700040500060300-- -- 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/