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Silva" CC: LKML Subject: RE: struct_size() using sizeof() vs offsetof() Thread-Topic: struct_size() using sizeof() vs offsetof() Thread-Index: AQHZ0KEzXPZ5QWstfUGUK20udA0j8K/0arpg Date: Mon, 21 Aug 2023 08:16:17 +0000 Message-ID: <55bb7e4f633340db9a9c013b91afedd6@AcuMS.aculab.com> References: <74e8cf91-d095-33e3-c548-34d80b691089@kernel.org> In-Reply-To: <74e8cf91-d095-33e3-c548-34d80b691089@kernel.org> 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 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RnJvbTogQWxlamFuZHJvIENvbG9tYXINCj4gU2VudDogVGh1cnNkYXksIEF1Z3VzdCAxNywgMjAy MyAxOjIzIEFNDQo+IA0KPiBIaSBLZWVzLCBHdXN0YXZvLA0KPiANCj4gSSd2ZSBiZWVuIGRpc2N1 c3Npbmcgd2l0aCBhIGZyaWVuZCBhYm91dCB0aGUgYXBwcm9wcmlhdGVuZXNzIG9mIHNpemVvZigp DQo+IHZzIG9mZnNldG9mKCkgZm9yIGNhbGN1bGF0aW5nIHRoZSBzaXplIG9mIGEgc3RydWN0dXJl IHdpdGggYSBmbGV4aWJsZQ0KPiBhcnJheSBtZW1iZXIgKEZBTSkuDQo+IA0KPiBBZnRlciByZWFk aW5nIEplbnMgR3VzdGVkdCdzIGJsb2cgcG9zdCBhYm91dCBpdFsxXSwgd2UgdHJpZWQgc29tZSB0 ZXN0cywNCj4gYW5kIHdlIGdvdCBzb21lIGludGVyZXN0aW5nIHJlc3VsdHMgdGhhdCBkaXNjb3Vy YWdlZCBtZSBmcm9tIHVzaW5nIHNpemVvZigpLg0KPiBTZWUgYmVsb3cuDQo+IA0KPiBCdXQgdGhl biwgc2FpZCBmcmllbmQgcG9pbnRlZCB0byBtZSB0aGF0IHRoZSBrZXJuZWwgdXNlcyBzaXplb2Yo KSBpbg0KPiBzdHJ1Y3Rfc2l6ZSgpLCBhbmQgd2Ugd29uZGVyZWQgd2h5IHlvdSB3b3VsZCBoYXZl IGNob3NlbiBpdC4gIEl0J3Mgc2FmZQ0KPiBhcyBsb25nIGFzIHlvdSBfa25vd18gdGhhdCB0aGVy ZSdzIG5vIHBhZGRpbmcsIG9yIHRoYXQgdGhlIGFsaWdubWVudCBvZg0KPiB0aGUgRkFNIGlzIGFz IGxhcmdlIGFzIHRoZSBwYWRkaW5nICh3aGljaCB5b3UgcHJvYmFibHkga25vdyBpbiB0aGUga2Vy bmVsKSwNCj4gYnV0IGl0IHNlZW1zIHNhZmVyIHRvIHVzZQ0KPiANCj4gCU1BWChzaXplb2Yocyks IG9mZnNldG9mKHMsIGZhbSkgKyBzaXplb2ZfbWVtYmVyKHMsIGZhbSkgKiBjb3VudCkNCj4gDQo+ IFRoZSB0aGluZyBpcywgaWYgdGhlcmUncyBhbnkgdHJhaWxpbmcgcGFkZGluZyBpbiB0aGUgc3Ry dWN0LCB0aGUgRkFNIG1heQ0KPiBvdmVybGFwIHRoZSBwYWRkaW5nLCBhbmQgdGhlIGNhbGN1bGF0 aW9uIHdpdGggc2l6ZW9mKCkgd2lsbCB3YXN0ZSBhIGZldw0KPiBieXRlcywgYW5kIGlmIG1pc3Vz ZWQgdG8gZ2V0IHRoZSBsb2NhdGlvbiBvZiB0aGUgRkFNLCB0aGUgcHJvYmxlbSB3aWxsIGJlDQo+ IGJpZ2dlciwgYXMgeW91J2xsIGdldCBhIHdyb25nIGxvY2F0aW9uLg0KPiANCj4gU28sIEkganVz dCB3YW50ZWQgdG8gcHJ5IHdoYXQgYW5kIGVzcGVjaWFsbHkgd2h5IHRoZSBrZXJuZWwgY2hvc2Ug dG8gcHJlZmVyDQo+IGEgc2ltcGxlIHNpemVvZigpLg0KPiANCj4gQ2hlZXJzLA0KPiBBbGV4DQo+ IA0KPiAtLS0NCi4uLi4uDQo+IAlzdHJjcHkocy0+ZmFtLCAiSGVsbG8sIHNpemVvZiEiKTsNCj4g CXAgPSAoY2hhciAqKSBzICsgc2l6ZW9mKHN0cnVjdCBzKTsNCj4gCXB1dHMocCk7DQoNCldoeSBv biBlYXJ0aCB3b3VsZCB5b3UgZXhwZWN0IHRoZSBhYm92ZSB0byBkbyBhbnl0aGluZyBzZW5zaWJs ZT8NCg0KSXQgaXMgYSBzaGFtZSB5b3UgY2FuIGp1c3QgdXNlIG9mZnNldG9mKHR5cGUsIG1lbWJl cltjb3VudCArIDFdKS4NClRoYXQgaXMgZmluZSBmb3IgY29uc3RhbnRzLCBidXQgdGhlIEMgbGFu Z3VhZ2UgcmVxdWlyZXMgb2Zmc2V0b2YoKQ0KdG8gYmUgYSBjb21waWxlLXRpbWUgY29uc3RhbnQg LSBJIGNhbid0IGhlbHAgZmVlbGluZyB0aGUgc3RhbmRhcmRzDQpib2R5IGRpZG4ndCBjb25zaWRl ciBub24tY29uc3RhbnQgYXJyYXkgb2Zmc2V0cy4NCihUaGUgY29tcGlsZXIgZm9yIGEgd2VsbCBr bm93biBPUyB3b24ndCBjb21waWxlIHRoYXQgKG9yIGFueXRoaW5nDQp0aGF0IGxvb2tzIGxpa2Ug aXQpIGV2ZW4gZm9yIGEgY29uc3RhbnQgYXJyYXkgc3Vic2NyaXB0ISkNCg0KVGhlIGFjdHVhbCBw cm9ibGVtIHdpdGggdXNpbmcgb2Zmc2V0b2YoKSBpcyB0aGF0IHlvdSBtaWdodCBlbmQNCnVwIHdp dGggc29tZXRoaW5nIHNtYWxsZXIgdGhhbiB0aGUgc3RydWN0dXJlIHNpemUuDQooV2hlbiB0aGUg dmFyaWFibGUgc2l6ZWQgYXJyYXkgaXMgc21hbGxlciB0aGFuIHRoZSBwYWRkaW5nLikNCg0KV2hp bGUgbWF4KCkgd2lsbCBnZW5lcmF0ZSBhIGNvbnN0YW50IGZvciBjb25zdGFudCBpbnB1dCwgaXQN CndpbGwgYmUgYSByZWFsIGNvbXBhcmUgZm9yIG5vbi1jb25zdGFudCBpbnB1dC4NCg0KCURhdmlk DQoNCi0NClJlZ2lzdGVyZWQgQWRkcmVzcyBMYWtlc2lkZSwgQnJhbWxleSBSb2FkLCBNb3VudCBG YXJtLCBNaWx0b24gS2V5bmVzLCBNSzEgMVBULCBVSw0KUmVnaXN0cmF0aW9uIE5vOiAxMzk3Mzg2 IChXYWxlcykNCg==