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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: AQHbKc6je06svG7vU0mpJNDFnNBsh7Ktq5PQgBYsN/GAAufo0A== Date: Sun, 24 Nov 2024 16:11:04 +0000 Message-ID: <2d7744d7ce504b288c3f1356f27910ec@AcuMS.aculab.com> References: <82cbb9983fef5ecf6f1cb33661e977172d40a7e6.1730166635.git.jpoimboe@kernel.org> <20241029032735.pw3bg64bpneqnfhk@treble.attlocal.net> <76bb85ceeb854e3ab68d87f846515306@AcuMS.aculab.com> <20241115230653.hfvzyf3aqqntgp63@jpoimboe> <20241121214011.iiup2fdwsys7hhts@jpoimboe> <20241122001223.t4uywacusrplpefq@jpoimboe> <20241122031115.5aasuktqrp2sidfj@jpoimboe> In-Reply-To: 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: kpEwDBHaq8EOCIbwspxirPcjN0C17oicXWgvPV-CY9M_1732464666 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 RnJvbTogTGludXMgVG9ydmFsZHMNCj4gU2VudDogMjIgTm92ZW1iZXIgMjAyNCAxOTozNQ0KPiAN Cj4gT24gRnJpLCAyMiBOb3YgMjAyNCBhdCAxMToxMywgTGludXMgVG9ydmFsZHMNCj4gPHRvcnZh bGRzQGxpbnV4LWZvdW5kYXRpb24ub3JnPiB3cm90ZToNCj4gPg0KPiA+IEkndmUgb25seSBjb21w aWxlZCBpdCBzbyBmYXIsIGFib3V0IHRvIGFjdHVhbGx5IGJvb3QgaW50byBpdC4NCj4gDQo+IExv b2tzIGZpbmUuIFNlbnQgb3V0IGEgcHJvcGVyIHBhdGNoIHdpdGggY29tbWl0IG1lc3NhZ2UgZXRj IGF0DQo+IA0KPiAgICBodHRwczovL2xvcmUua2VybmVsLm9yZy9hbGwvMjAyNDExMjIxOTMzMDUu NzMxNi0xLXRvcnZhbGRzQGxpbnV4LWZvdW5kYXRpb24ub3JnLw0KPiANCj4gYmVjYXVzZSBpdCBs b29rcyBnb29kIHRvIG1lLiBDb21tZW50cz8NCg0KK3N0YXRpYyBfX2Fsd2F5c19pbmxpbmUgaW50 IGZ1dGV4X3JlYWRfaW5hdG9taWModTMyICpkZXN0LCB1MzIgX191c2VyICpmcm9tKQ0KK3sNCisJ dTMyIHZhbDsNCisNCisJaWYgKGNhbl9kb19tYXNrZWRfdXNlcl9hY2Nlc3MoKSkNCisJCWZyb20g PSBtYXNrZWRfdXNlcl9hY2Nlc3NfYmVnaW4oZnJvbSk7DQorCWVsc2UgaWYgKCF1c2VyX3JlYWRf YWNjZXNzX2JlZ2luKGZyb20sIHNpemVvZigqZnJvbSkpKQ0KKwkJcmV0dXJuIC1FRkFVTFQ7DQor CXVuc2FmZV9nZXRfdXNlcih2YWwsIGZyb20sIEVmYXVsdCk7DQorCXVzZXJfYWNjZXNzX2VuZCgp Ow0KKwkqZGVzdCA9IHZhbDsNCisJcmV0dXJuIDA7DQorRWZhdWx0Og0KKwl1c2VyX2FjY2Vzc19l bmQoKTsNCisJcmV0dXJuIC1FRkFVTFQ7DQorfQ0KKw0KK3N0YXRpYyBpbmxpbmUgaW50IGZ1dGV4 X2dldF92YWx1ZV9sb2NrZWQodTMyICpkZXN0LCB1MzIgX191c2VyICpmcm9tKQ0KK3sNCisJaW50 IHJldDsNCisNCisJcGFnZWZhdWx0X2Rpc2FibGUoKTsNCisJcmV0ID0gZnV0ZXhfcmVhZF9pbmF0 b21pYyhkZXN0LCBmcm9tKTsNCisJcGFnZWZhdWx0X2VuYWJsZSgpOw0KKw0KKwlyZXR1cm4gcmV0 Ow0KK30NCg0KSXMgdGhlcmUgYW4gJ3Vuc2FmZV9nZXRfdXNlcl9ub2ZhdWx0KCknIHRoYXQgdXNl cyBhIHRyYXAgaGFuZGxlcg0KdGhhdCB3b24ndCBmYXVsdCBpbiBhIHBhZ2U/DQpUaGF0IHdvdWxk IHNhdmUgdGhlIGluYy9kZWMgZG9uZSBieSBwYWdlZmF1bHRfZW4vZGlzYWJsZSgpLg0KDQpJJ2Qg YWxzbyBoYXZlIHRob3VnaHQgdGhhdCB0aGUgdHJhcCBoYW5kbGVyIGZvciB1bnNhZmVfZ2V0X3Vz ZXIoKQ0Kd291bGQganVtcCB0byB0aGUgRWZhdWx0IGxhYmVsIGhhdmluZyBhbHJlYWR5IGRvbmUg dXNlcl9hY2Nlc3NfZW5kKCkuDQpCdXQgbWF5YmUgaXQgZG9lc24ndCB3b3JrIG91dCB0aGF0IHdh eT8NCg0KCURhdmlkDQoNCi0NClJlZ2lzdGVyZWQgQWRkcmVzcyBMYWtlc2lkZSwgQnJhbWxleSBS b2FkLCBNb3VudCBGYXJtLCBNaWx0b24gS2V5bmVzLCBNSzEgMVBULCBVSw0KUmVnaXN0cmF0aW9u IE5vOiAxMzk3Mzg2IChXYWxlcykNCg==