From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 087C8EE57DF for ; Mon, 11 Sep 2023 16:39:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7D2A56B02A2; Mon, 11 Sep 2023 12:39:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 781D96B02A4; Mon, 11 Sep 2023 12:39:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 64A986B02A6; Mon, 11 Sep 2023 12:39:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 54FB66B02A2 for ; Mon, 11 Sep 2023 12:39:16 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 293D51409CF for ; Mon, 11 Sep 2023 16:39:16 +0000 (UTC) X-FDA: 81224876712.10.8F2DF25 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by imf16.hostedemail.com (Postfix) with ESMTP id 06823180024 for ; Mon, 11 Sep 2023 16:39:11 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=aculab.com; spf=pass (imf16.hostedemail.com: domain of david.laight@aculab.com designates 185.58.86.151 as permitted sender) smtp.mailfrom=david.laight@aculab.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1694450353; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a2Mv+LUaJ9b/RkhaXnqR2rywsm+C7whWGk5Vey6hvFA=; b=JtnpiKJbodYc+WVG1VMIS9RyeWJSIPL6TiaCYsv54V6H1rAlGtUNfm3fHdHMZmgXWD6Ptt P52/CC7ehoXs35pr6c7aCb7i4ipIF9frnB+vTlegWi2eZnedW7d4uJHcb6qZ3nFWhpqE8X VBv5kXzIRtk0jbRS6aWLYc8qFlfl7mc= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=aculab.com; spf=pass (imf16.hostedemail.com: domain of david.laight@aculab.com designates 185.58.86.151 as permitted sender) smtp.mailfrom=david.laight@aculab.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1694450353; a=rsa-sha256; cv=none; b=ymAEvFbFLPxctM5u5Ia2XPk+5sb7f2sUxf0CcK3cJjop+3r1ycsE7dGY9W9NC+JVt1+Oz7 6Zfsdg17bfad/a8zwVEA8KX/Jchz6J/ZSjmJjUTBundK5IYKBnvyb59kLkE2dKSX4bT7rt 7do3mIoLET0dZnEteu3p7LsrlmKLY+E= Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-93-0C-wAUcbNBCmRkvM2PftBQ-1; Mon, 11 Sep 2023 17:38:59 +0100 X-MC-Unique: 0C-wAUcbNBCmRkvM2PftBQ-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Mon, 11 Sep 2023 17:38:46 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Mon, 11 Sep 2023 17:38:46 +0100 From: David Laight To: 'Vlastimil Babka' , 'Kees Cook' CC: "linux-kernel@vger.kernel.org" , "'linux-mm@kvack.org'" , 'Christoph Lameter' , 'Pekka Enberg' , 'David Rientjes' , 'Joonsoo Kim' , "'Andrew Morton'" , 'Eric Dumazet' , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Roman Gushchin Subject: RE: Subject: [PATCH v2] slab: kmalloc_size_roundup() must not return 0 for non-zero size Thread-Topic: Subject: [PATCH v2] slab: kmalloc_size_roundup() must not return 0 for non-zero size Thread-Index: Adnhh8rbtLpHk7QBQE+HpPR0NWDZ5gAMq8SAABymU5AApLGGAAACRmZQ///11gD//+uuIA== Date: Mon, 11 Sep 2023 16:38:46 +0000 Message-ID: References: <4d31a2bf7eb544749023cf491c0eccc8@AcuMS.aculab.com> <202309071235.CB4F6B2@keescook> <20ca0a567a874052a1161e9be0870463@AcuMS.aculab.com> <1bf41b7c8d7c428c8bfb5504ec9f680e@AcuMS.aculab.com> <1d634412-c0e5-4c16-92a4-447bde684ad6@suse.cz> In-Reply-To: <1d634412-c0e5-4c16-92a4-447bde684ad6@suse.cz> 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 X-Rspamd-Queue-Id: 06823180024 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: yffxprw336daegfxy3gyajdybzthn18y X-HE-Tag: 1694450351-392375 X-HE-Meta: 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 P6DDXNQx /XNhR4dMWzVd0ur/i02+b8FLYn8pfdLvDtIbxmPboxUBpvNBWur9XTx2IsthvGeBW6Xsn4qs9b51R8ckhExadBsj9Je7qqHpgvugVAtFmjdrnoh1B9Q/SvjM/RbUlKcK29eO/6gwfuRWI4KU7TRnOC6pTmDH7KxbP30xHcLwcftAVc/nPhA8Wc6GFJ8ZOu8JW7Wy0wqD8xaRbYT1nmQcQPJTBeGr6s66YVgQaFYL32JN1esr2LUuTvcM8/JpybhbV06tDsZciWgopJRm5yGKA4AmJl9lC6XZegoTvtDhzZuJcCFU3D+QHLwpXzZ+IxO6FD8DsUUUPRjy9i9Mqho8l8EI6ORIeTlntcdet2ulFRzUqtrar8yRUKd6iGqlPd3QE0vLRpO2O3borSwIRO1zvmTyFgEtse1uChHNyCYb84+OJytGahpqe4DqgeA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: RnJvbTogVmxhc3RpbWlsIEJhYmthDQo+IFNlbnQ6IDExIFNlcHRlbWJlciAyMDIzIDE3OjIzDQo+ IA0KPiBPbiA5LzExLzIzIDE4OjEyLCBEYXZpZCBMYWlnaHQgd3JvdGU6DQo+ID4gRnJvbTogVmxh c3RpbWlsIEJhYmthDQo+ID4+IFNlbnQ6IDExIFNlcHRlbWJlciAyMDIzIDE2OjU0DQo+ID4+DQo+ ID4+IE9uIDkvOC8yMyAxMDoyNiwgRGF2aWQgTGFpZ2h0IHdyb3RlOg0KPiA+PiA+IEZyb206IEtl ZXMgQ29vaw0KPiA+PiA+PiBTZW50OiAwNyBTZXB0ZW1iZXIgMjAyMyAyMDozOA0KPiA+PiA+Pg0K PiA+PiA+PiBPbiBUaHUsIFNlcCAwNywgMjAyMyBhdCAxMjo0MjoyMFBNICswMDAwLCBEYXZpZCBM YWlnaHQgd3JvdGU6DQo+ID4+ID4+ID4gVGhlIHR5cGljYWwgdXNlIG9mIGttYWxsb2Nfc2l6ZV9y b3VuZHVwKCkgaXM6DQo+ID4+ID4+ID4gCXB0ciA9IGttYWxsb2Moc3ogPSBrbWFsbG9jX3NpemVf cm91bmR1cChzaXplKSwgLi4uKTsNCj4gPj4gPj4gPiAJaWYgKCFwdHIpIHJldHVybiAtRU5PTUVN Lg0KLi4uDQo+ID4+ID4+ID4gKwkJYyA9IGttYWxsb2Nfc2xhYihzaXplLCBHRlBfS0VSTkVMLCAw KTsNCj4gPj4gPj4gPiArCQlyZXR1cm4gbGlrZWx5KGMpID8gYy0+b2JqZWN0X3NpemUgOiBzaXpl Ow0KPiA+PiA+Pg0KPiA+PiA+PiBJIHdvdWxkIGxpa2UgdG8gaGF2ZSB0aGlzIGZhaWwgInNhZmUi LiBjIHNob3VsZCBuZXZlciBiZSBOVUxMIGhlcmUsIHNvDQo+ID4+ID4+IGxldCdzIHJldHVybiAi S01BTExPQ19NQVhfU0laRSArIDEiIHRvIGZvcmNlIGZhaWx1cmVzLg0KPiA+PiA+DQo+ID4+ID4g V2h5IGV2ZW4gdHJ5IHRvIGZvcmNlIGZhaWx1cmUgaGVyZT8NCj4gPj4gPiBUaGUgd2hvbGUgZnVu Y3Rpb24gaXMganVzdCBhbiBvcHRpbWlzYXRpb24gc28gdGhhdCB0aGUgY2FsbGVyDQo+ID4+ID4g Y2FuIHVzZSB0aGUgc3BhcmUgc3BhY2UuDQo+ID4+ID4NCj4gPj4gPiBUaGUgb25seSB0aGluZyBp dCBtdXN0bid0IGRvIGlzIHJldHVybiBhIHNtYWxsZXIgdmFsdWUuDQo+ID4+DQo+ID4+IElmICJj IiBpcyBOVUxMIGl0IG1lYW5zIGVpdGhlciB0aGUga2VybmVsIGJ1aWxkIG11c3QgYmUgYnJva2Vu IGUuZy4gYnkNCj4gPj4gc29tZWJvZHkgYnJlYWtpbmcgdGhlIEtNQUxMT0NfTUFYX0NBQ0hFX1NJ WkUgdmFsdWUsIGFuZCB3ZSBjb3VsZCBqdXN0IGlnbm9yZQ0KPiA+PiBjIGJlaW5nIE5VTEwgYW5k IGxldCBpdCBjcmFzaCBiZWNhdXNlIG9mIHRoYXQuDQo+ID4+IEJ1dCBJIHRoaW5rIGl0IGNhbiBh bHNvIGJlIE5VTEwgZHVlIHRvIHRyeWluZyB0byBjYWxsIGttYWxsb2Nfc2l6ZV9yb3VuZHVwKCkN Cj4gPj4gdG9vIGVhcmx5LCB3aGVuIGttYWxsb2NfY2FjaGVzIGFycmF5IGlzIG5vdCB5ZXQgcG9w dWxhdGVkLiBOb3RlIGlmIHdlIGNhbGwNCj4gPj4ga21hbGxvYygpIGl0c2VsZiB0b28gZWFybHks IHdlIGdldCBhIE5VTEwgYXMgYSByZXN1bHQsIEFGQUlDUy4gSSBjYW4gaW1hZ2luZQ0KPiA+PiB0 d28gc2NlbmFyaW9zOg0KPiA+Pg0KPiA+PiAtIGttYWxsb2Nfc2l6ZV9yb3VuZHVwKCkgaXMgY2Fs bGVkIHdpdGggcmVzdWx0IGltbWVkaWF0ZWx5IGZlZCB0byBrbWFsbG9jKCkNCj4gPj4gdGhhdCBo YXBwZW5zIHRvbyBlYXJseSwgaW4gdGhhdCBjYXNlIHdlIGJlc3Qgc2hvdWxkIG5vdCBjcmFzaCBv biBjIGJlaW5nDQo+ID4+IE5VTEwgYW5kIG1ha2Ugc3VyZSB0aGUga21hbGxvYygpIHJldHVybnMg TlVMTC4NCj4gPj4gLSBrbWFsbG9jX3NpemVfcm91bmR1cCgpIGlzIGNhbGxlZCBpbiBzb21lIGlu aXQgY29kZSB0byBnZXQgYSB2YWx1ZSB0aGF0DQo+ID4+IHNvbWUgbGF0ZXIga21hbGxvYygpIGNh bGwgdXNlcy4gV2UgbWlnaHQgd2FudCBhbHNvIG5vdCBjcmFzaCBpbiB0aGF0IGNhc2UsDQo+ID4+ IGJ1dCBpbmZvcm1pbmcgdGhlIGRldmVsb3BlciB0aGF0IHRoZXkgZGlkIHNvbWV0aGluZyB3cm9u ZyB3b3VsZCBiZSBhbHNvIHVzZWZ1bD8NCj4gPj4NCj4gPj4gQ2xlYXJseSByZXR1cm5pbmcgMCBp ZiBjID09IE5VTEwsIGFzIGRvbmUgY3VycmVudGx5LCBpcyB3cm9uZyBmb3IgYm90aA0KPiA+PiBz Y2VuYXJpb3MuIFJldHVuaW5nICJzaXplIiBpcyBPSyBmb3IgdGhlIGZpcnN0IHNjZW5hcmlvLCBh bHNvIHZhbGlkIGZvciB0aGUNCj4gPj4gc2Vjb25kIG9uZSwgYnV0IHRoZSBjYWxsZXIgd2lsbCBz aWxlbnRseSBsb3NlIHRoZSBiZW5lZml0IG9mDQo+ID4+IGttYWxsb2Nfc2l6ZV9yb3VuZHVwKCkg YW5kIHRoZSBkZXZlbG9wZXIgaW50cm9kdWNpbmcgdGhhdCB3b24ndCByZWFsaXplIGl0J3MNCj4g Pj4gZG9uZSB0b28gZWFybHkgYW5kIGNvdWxkIGJlIGZpeGVkLg0KPiA+DQo+ID4gSSdtIHN1cmUg dGhhdCB3b24ndCBtYXR0ZXIuDQo+IA0KPiBGb3IgdGhlIHBlcmZvcm1hbmNlLCBzdXJlLiBJdCBq dXN0IGZlZWxzIHNpbGx5IHRvIG1lIHRvIGhhdmUgYSBjb2RlIHRoYXQNCj4gbG9va3MgbGlrZSBp dCBkb2VzIHNvbWV0aGluZywgYnV0IHNpbGVudGx5IGRvZXNuJ3QuIExlYWRzIHRvIGNhcmdvIGN1 bHQNCj4gY29weWluZyBpdCB0byBvdGhlciBwbGFjZXMgZXRjLg0KPiANCj4gPj4gU28gcGVyaGFw cyB0aGUgYmVzdCB3b3VsZCBiZSB0byByZXR1cm4gc2l6ZSBmb3IgYyA9PSBOVUxMLCBidXQgYWxz byBkbyBhDQo+ID4+IFdBUk5fT05DRT8NCj4gPg0KPiA+IFRoYXQgd291bGQgYWRkIGEgcmVhbCBm dW5jdGlvbiBjYWxsIHRvIGFuIG90aGVyd2lzZSBsZWFmIGZ1bmN0aW9uDQo+ID4gYW5kIGFsbW9z dCBjZXJ0YWlubHkgcmVxdWlyZSB0aGUgY29tcGlsZXIgY3JlYXRlIGEgc3RhY2sgZnJhbWUuDQo+ IA0KPiBIbSBJIHRob3VnaHQgV0FSTiBpcyBkb25lIGJ5IHRyaXBwaW5nIG9uIHVuZGVmaW5lZCBp bnN0cnVjdGlvbiBsaWtlIEJVRw0KPiB0aGVzZSBkYXlzLiBBbHNvIGFueSBjb2RlIHRoYXQgYWNj ZXB0cyB0aGUgY2FsbCB0byBrbWFsbG9jX3NpemVfcm91bmR1cA0KPiBwcm9iYWJseSBjb3VsZCBh Y2NlcHQgdGhhdCB0b28uDQoNCkl0J3MgcHJvYmFibHkganVzdCB3b3J0aCByZW1vdmluZyB0aGUg YyA9PSBOVUxMIGNoZWNrIGFuZA0KYXNzdW1pbmcgdGhlcmUgd29uJ3QgYmUgYW55IGZhbGxvdXQu DQpUaGUgTlVMTCBwb2ludGVyIGRlcmVmIGlzIGFuIGVhc3kgdG8gZGVidWcgYXMgYW55dGhpbmcg ZWxzZS4NCg0KSWYgaXQgZ2V0cyBjYWxsZWQgaW4gYW55IGVhcmx5IGluaXQgY29kZSBpdCdsbCBz b29uIHNob3cgdXAuDQoNCglEYXZpZA0KDQotDQpSZWdpc3RlcmVkIEFkZHJlc3MgTGFrZXNpZGUs IEJyYW1sZXkgUm9hZCwgTW91bnQgRmFybSwgTWlsdG9uIEtleW5lcywgTUsxIDFQVCwgVUsNClJl Z2lzdHJhdGlvbiBObzogMTM5NzM4NiAoV2FsZXMpDQo=