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Lu" , "Moreira, Joao" , "Nuzman, Joseph" , "Steven Rostedt" , "Gross, Jurgen" , "Masami Hiramatsu" , Alexei Starovoitov , Daniel Borkmann , Peter Collingbourne , Kees Cook Subject: RE: [patch 00/38] x86/retbleed: Call depth tracking mitigation Thread-Topic: [patch 00/38] x86/retbleed: Call depth tracking mitigation Thread-Index: AQHYnSyhi03gNC/QIkePUsvbFv4MOq2JW8MQ Date: Thu, 21 Jul 2022 22:01:12 +0000 Message-ID: References: <87fsiyuhyz.ffs@tglx> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RnJvbTogTGludXMgVG9ydmFsZHMNCj4gU2VudDogMjEgSnVseSAyMDIyIDE5OjA3DQouLi4NCj4g IChiKSBzaW5jZSB5b3UgaGF2ZSB0aGF0IHIxMCB1c2UgYW55d2F5LCB3aHkgY2FuJ3QgeW91IGp1 c3QgZ2VuZXJhdGUgdGhlIHNpbXBsZXINCj4gDQo+ICAgICAgICAgbW92bCAkLUlNTSwlcjEwZA0K PiAgICAgICAgIGFkZGwgLTQoJWNhbGxkZXN0KSwlcjEwZA0KPiANCj4gICAgICBpbnN0ZWFkPyBZ b3Ugb25seSBuZWVkIFpGIGFueXdheS4NCj4gDQo+ICAgICAgTWF5YmUgeW91IG5lZWQgdG8gYWRk IHNvbWUgInIxMCBpcyBjbG9iYmVyZWQiIHRoaW5nLCBJIGRvbid0IGtub3cuDQo+IA0KPiBCdXQg YWdhaW46IEkgZG9uJ3Qga25vdyBsbHZtLCBzbyB0aGUgYWJvdmUgaXMgYmFzaWNhbGx5IG1lIGp1 c3QgZG9pbmcNCj4gdGhlICJwYXR0ZXJuIG1hdGNoaW5nIG1vbmtleSIgdGhpbmcuDQo+IA0KPiAg ICAgICAgICAgICAgTGludXMNCg0KU2luY2U6ICJJZiB0aGUgY2FsbGVlIGlzIGEgdmFyaWFkaWMg ZnVuY3Rpb24sIHRoZW4gdGhlIG51bWJlciBvZiBmbG9hdGluZw0KcG9pbnQgYXJndW1lbnRzIHBh c3NlZCB0byB0aGUgZnVuY3Rpb24gaW4gdmVjdG9yIHJlZ2lzdGVycyBtdXN0IGJlIHByb3ZpZGVk DQpieSB0aGUgY2FsbGVyIGluIHRoZSBBTCByZWdpc3Rlci4iDQoNCkFuZCB0aGF0IHRoYXQgbmV2 ZXIgaGFwcGVucyBpbiB0aGUga2VybmVsIHlvdSBjYW4gdXNlICVlYXggaW5zdGVhZA0Kb2YgJXIx MGQuDQoNCkV2ZW4gaW4gdXNlcnNwYWNlICVhbCBjYW4gYmUgc2V0IG5vbi16ZXJvIGFmdGVyIHRo ZSBzaWduYXR1cmUgY2hlY2suDQoNCklmIHlvdSBhcmUgd2lsbGluZyB0byBjdXQgdGhlIHNpZ25h dHVyZSBkb3duIHRvIDI2IGJpdHMgYW5kDQp0aGVuIGVuc3VyZSB0aGF0IG9uZSBvZiB0aGUgYnl0 ZXMgb2YgLUlNTSAob3IgfklNTSBpZiB5b3UNCnVzZSB4b3IpIGlzIDB4Y2MgYW5kIGp1bXAgYmFj ayB0byB0aGF0IG9uIGVycm9yIHRoZSBjaGVjaw0KYmVjb21lczoNCgltb3ZsCSQtSU1NLCVlYXgN CjE6CWFkZGwJLTQoJWNhbGxkZXN0KSwlZWF4DQoJam56CTFiLTEJLy8gb3IgLTIsIC0zLCAtNA0K CWFkZAkkbnVtX2ZwX2FyZ3MsJWVheAkvLyBJZiBuZWVkZWQgbm9uLXplcm8NCgljYWxsCSVjYWxs ZGVzdA0KDQpJIHRoaW5rIHRoYXQgYWRkcyAxMCBieXRlcyB0byB0aGUgY2FsbCBzaXRlLg0KQWx0 aG91Z2ggd2l0aCByZXRwb2xpbmUgdGh1bmtzIChhbmQgbm8gZnAgdmFyYXJncyBjYWxscykNCmFs bCBidXQgdGhlIGluaXRpYWwgbW92bCBjYW4gZ28gaW50byB0aGUgdGh1bmsuDQoNCglEYXZpZA0K DQotDQpSZWdpc3RlcmVkIEFkZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9hZCwgTW91bnQgRmFy bSwgTWlsdG9uIEtleW5lcywgTUsxIDFQVCwgVUsNClJlZ2lzdHJhdGlvbiBObzogMTM5NzM4NiAo V2FsZXMpDQo=