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Shutemov" Subject: RE: [PATCH v3 2/6] x86/uaccess: Avoid barrier_nospec() in 64-bit __get_user() Thread-Topic: [PATCH v3 2/6] x86/uaccess: Avoid barrier_nospec() in 64-bit __get_user() Thread-Index: AQHbKc6je06svG7vU0mpJNDFnNBsh7Ktq5PQ Date: Fri, 8 Nov 2024 17:12:53 +0000 Message-ID: <76bb85ceeb854e3ab68d87f846515306@AcuMS.aculab.com> References: <82cbb9983fef5ecf6f1cb33661e977172d40a7e6.1730166635.git.jpoimboe@kernel.org> <20241029032735.pw3bg64bpneqnfhk@treble.attlocal.net> In-Reply-To: <20241029032735.pw3bg64bpneqnfhk@treble.attlocal.net> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 6EzCnmUf2xL8WnHlINObZ2s3wcN5h3Np277CcPRrvDs_1731085973 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 RnJvbTogSm9zaCBQb2ltYm9ldWYNCj4gU2VudDogMjkgT2N0b2JlciAyMDI0IDAzOjI4DQo+IA0K PiBPbiBNb24sIE9jdCAyOCwgMjAyNCBhdCAwNjo1NjoxNVBNIC0wNzAwLCBKb3NoIFBvaW1ib2V1 ZiB3cm90ZToNCj4gPiBUaGUgYmFycmllcl9ub3NwZWMoKSBpbiA2NC1iaXQgX19nZXRfdXNlcigp IGlzIHNsb3cuICBJbnN0ZWFkIHVzZQ0KPiA+IHBvaW50ZXIgbWFza2luZyB0byBmb3JjZSB0aGUg dXNlciBwb2ludGVyIHRvIGFsbCAxJ3MgaWYgYSBwcmV2aW91cw0KPiA+IGFjY2Vzc19vaygpIG1p c3ByZWRpY3RlZCB0cnVlIGZvciBhbiBpbnZhbGlkIGFkZHJlc3MuDQo+IA0KPiBMaW51cyBwb2lu dGVkIG91dCB0aGF0IF9fZ2V0X3VzZXIoKSBtYXkgYmUgdXNlZCBieSBzb21lIGNvZGUgdG8gYWNj ZXNzDQo+IGJvdGgga2VybmVsIGFuZCB1c2VyIHNwYWNlIGFuZCBpbiBmYWN0IEkgZm91bmQgb25l IHN1Y2ggdXNhZ2UgaW4NCj4gdmNfcmVhZF9tZW0oKS4uLi4NCj4gDQo+IFNvIEkgc2VsZi1OQUsg dGhpcyBwYXRjaCBmb3Igbm93Lg0KPiANCj4gU3RpbGwsIGl0IHdvdWxkIGJlIGdyZWF0IGlmIHBh dGNoIDEgY291bGQgZ2V0IG1lcmdlZCBhcyB0aGF0IGdpdmVzIGENCj4gc2lnbmlmaWNhbnQgcGVy Zm9ybWFuY2UgYm9vc3QuDQoNCkknbSBhIGJpdCBsYXRlIHRvIHRoZSBwYXJ0eSBhbmQgc3RpbGwg YSB3ZWVrIGJlaGluZCA6LSgNCg0KQnV0IEkndmUgd29uZGVyZWQgaWYgYWNjZXNzX29rKCkgb3Vn aHQgdG8gYmUgaW1wbGVtZW50ZWQgdXNpbmcgYW4NCidhc20gZ290byB3aXRoIG91dHB1dCcgLSBt dWNoIGxpa2UgZ2V0X3VzZXIoKS4NCg0KVGhlbiB0aGUgdXNlIHdvdWxkIGJlOg0KCW1hc2tlZF9h ZGRyZXNzID0gYWNjZXNzX29rKG1heWJlX2JhZF9hZGRyZXNzLCBzaXplLCBqdW1wX2xhYmVsKTsN CndpdGggbGF0ZXIgdXNlciBhY2Nlc3NlcyB1c2luZyB0aGUgbWFza2VkX2FkZHJlc3MuDQoNCk9u Y2UgeW91J3ZlIGRvbmUgdGhhdCBfX2dldF91c2VyKCkgZG9lc24ndCBuZWVkIHRvIGNvbnRhaW4g YWRkcmVzcyBtYXNraW5nLg0KDQpHaXZlbiB0aGF0IGNsYWMvc3RhYyBpYXJlIHNvIHNsb3cgc2hv dWxkIHRoZXJlIGFyZSBiZSBzb21ldGhpbmcgdGhhdA0KY29tYmluZXMgc3RhYyB3aXRoIGFjY2Vz c19vaygpIGJyYWNrZXRlZCB3aXRoIGEgJ3VzZXJfYWNjZXNzX2VuZCcNCm9yIGFuIGFjdHVhbCBm YXVsdC4NCg0KSSd2ZSBzdXJlIHRoZXJlIGlzIGNvZGUgKG1heWJlIHJlYWRpbmcgaW92ZWNbXSBv ciBpbiBzeXNfcG9sbCgpKQ0KdGhhdCB3YW50cyB0byBkbyBtdWx0aXBsZSBnZXQvcHV0X3VzZXIg aW4gYSBzaG9ydCBsb29wIHJhdGhlciB0aGF0DQpjYWxsaW5nIGNvcHlfdG8vZnJvbV91c2VyKCku DQoNCglEYXZpZA0KDQotDQpSZWdpc3RlcmVkIEFkZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9h ZCwgTW91bnQgRmFybSwgTWlsdG9uIEtleW5lcywgTUsxIDFQVCwgVUsNClJlZ2lzdHJhdGlvbiBO bzogMTM5NzM4NiAoV2FsZXMpDQo=