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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: AQHbKc6je06svG7vU0mpJNDFnNBsh7Ktq5PQgAuONbKAAUs+QA== Date: Sat, 16 Nov 2024 21:38:35 +0000 Message-ID: <4055e18be7ff4f1f83fb9a4b6a8bc312@AcuMS.aculab.com> References: <82cbb9983fef5ecf6f1cb33661e977172d40a7e6.1730166635.git.jpoimboe@kernel.org> <20241029032735.pw3bg64bpneqnfhk@treble.attlocal.net> <76bb85ceeb854e3ab68d87f846515306@AcuMS.aculab.com> <20241115230653.hfvzyf3aqqntgp63@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: Hj-nizpus-nveCwF3X3PaXcJjFhrlEu4K9JiB89Ca7I_1731793115 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 RnJvbTogTGludXMgVG9ydmFsZHMNCj4gU2VudDogMTYgTm92ZW1iZXIgMjAyNCAwMToyNw0KPiAN Cj4gT24gRnJpLCAxNSBOb3YgMjAyNCBhdCAxNTowNiwgSm9zaCBQb2ltYm9ldWYgPGpwb2ltYm9l QGtlcm5lbC5vcmc+IHdyb3RlOg0KPiA+DQo+ID4gSXQncyBzYWQgdGhhdCBfX2dldF91c2VyKCkg aXMgbm93IHNsb3dlciB0aGFuIGdldF91c2VyKCkgb24geDg2LCBpdCBraW5kDQo+ID4gb2YgZGVm ZWF0cyB0aGUgd2hvbGUgcG9pbnQhDQo+IA0KPiBXZWxsLCBob25lc3RseSwgd2UndmUgYmVlbiB0 cnlpbmcgdG8gZ2V0IGF3YXkgZnJvbSBfX2dldF91c2VyKCkgYW5kDQo+IF9fcHV0X3VzZXIoKSBm b3IgYSBsb25nIGxvbmcgdGltZS4NCj4gDQo+IFdpdGggQ0xBQy9TVEFDLCBpdCdzIGJlZW4gcHJv YmFibHkgYSBkZWNhZGUgb3IgdHdvIHNpbmNlIF9fZ2V0X3VzZXIoKQ0KPiBhbmQgZnJpZW5kcyB3 ZXJlIGFjdHVhbGx5IGEgd29ydGh3aGlsZSBvcHRpbWl6YXRpb24sIHNvIGxldCdzIGp1c3QNCj4g c3RyaXZlIHRvIGdldCByaWQgb2YgdGhlIG9uZXMgdGhhdCBtYXR0ZXIuDQoNClRoaW5rcy4uLi4N Cg0KSWYgX19nZXRfdXNlcigpIGlzIHRoZSBzYW1lIGFzIGdldF91c2VyKCkgdGhlbiBhbGwgdGhl IGFjY2Vzc19vaygpDQpvdXRzaWRlIG9mIGdldC9wdXRfdXNlcigpIGFuZCBjb3B5X3RvL2Zyb21f dXNlcigpIGNhbiBiZSByZW1vdmVkDQpiZWNhdXNlIHRoZXkgYXJlIHBvaW50bGVzcyAoYW55b25l IHRoYXQgYnJhdmU/KS4NClRoZXJlIGlzIG5vIHBvaW50IG9wdGltaXNpbmcgdGhlIGNvZGUgdG8g ZmFzdC1wYXRoIGJhZCB1c2VyIHBvaW50ZXJzLg0KDQo+IFdlIGFscmVhZHkgaGF2ZSB0aGlzIHdp dGggdXNlcl9hY2Nlc3NfYmVnaW4oKSArIHVuc2FmZV9nZXRfdXNlcigpLg0KPiBUaGVyZSdzIGFs c28gYSB2ZXJzaW9uIHdoaWNoIG1hc2tzIHRoZSBhZGRyZXNzOiBtYXNrZWRfdXNlcl9hY2Nlc3Nf YmVnaW4oKS4NCg0KVGhhdCBzb3VuZHMgYXMgdGhvdWdoIGl0IGlzIGJlZ2dpbmcgZm9yIGEgc2lt cGxlIHRvIHVzZToNCgltYXNrZWRfYWRkciA9IHVzZXJfYWNjZXNzX2JlZ2luKGFkZHIsIHNpemUs IGVycm9yX2xhYmVsKTsNCmFuZA0KCXZhbCA9IHVuc2FmZV9nZXRfdXNlcihtYXNrZWRfYWRkciwg ZXJyb3JfbGFiZWwpOw0KZm9ybT8NClByb2JhYmx5IHdpdGggb2JqdG9vbCBjaGVja2luZyB0aGV5 IGFyZSBhbGwgaW4gYSB2YWxpZCBzZXF1ZW5jZQ0Kd2l0aCBubyBmdW5jdGlvbnMgY2FsbHMgKGV0 YykuDQoNCklmIGFkZHJlc3MgbWFza2luZyBpc24ndCBuZWVkZWQgKGJ5IGFuIGFyY2hpdGVjdHVy ZSkgdGhlIGFkZHJlc3MgY2FuIGJlIGxlZnQNCnVuY2hhbmdlZC4NCg0KQSBxdWljayBncmVwIHNo b3dzIGFjY2Vzc19vaygpIGluIDY2IC5jIGFuZCA4IC5oIGZpbGVzIG91dHNpZGUgdGhlIGFyY2gg Y29kZS4NCkFuZCA2OSAuYyBmaWxlIGluIGFyY2gsIG1vc3Qgb2YgdGhlIGFyY2ggLmggYXJlIHVh Y2Nlc3MuaCBhbmQgZnV0ZXguaC4NCkkgc3VzcGVjdCB0aGUgYXVkaXQgd291bGRuJ3QgdGFsZSB0 aGF0IGxvbmcuDQpHZXR0aW5nIGFueSBwYXRjaGVzIGFjY2VwdGVkIGlzIGFub3RoZXIgbWF0dGVy Lg0KDQoJRGF2aWQNCg0KLQ0KUmVnaXN0ZXJlZCBBZGRyZXNzIExha2VzaWRlLCBCcmFtbGV5IFJv YWQsIE1vdW50IEZhcm0sIE1pbHRvbiBLZXluZXMsIE1LMSAxUFQsIFVLDQpSZWdpc3RyYXRpb24g Tm86IDEzOTczODYgKFdhbGVzKQ0K