From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1035759AbdD1KtY (ORCPT ); Fri, 28 Apr 2017 06:49:24 -0400 Received: from mout.web.de ([212.227.15.14]:64716 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1032028AbdD1KtQ (ORCPT ); Fri, 28 Apr 2017 06:49:16 -0400 Subject: Re: [alsa-devel] [PATCH 1/3] ASoC: simple-card: Use devm_kcalloc() in asoc_simple_card_parse_aux_devs() To: Alexandre Belloni Cc: alsa-devel@alsa-project.org, Jaroslav Kysela , Kuninori Morimoto , Liam Girdwood , Mark Brown , Nikita Yushchenko , Takashi Iwai , kernel-janitors@vger.kernel.org, LKML References: <8b5e37d1-17c5-4551-801f-ca7939d5efd7@users.sourceforge.net> <8c8c6979-0368-9ef5-2e10-57199f0bc03e@users.sourceforge.net> <20170428085735.i7xpxph24t5v5f5q@piout.net> From: SF Markus Elfring Message-ID: <49bbbcac-f970-bbb9-c66b-c9c25229cc6a@users.sourceforge.net> Date: Fri, 28 Apr 2017 12:48:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.0.1 MIME-Version: 1.0 In-Reply-To: <20170428085735.i7xpxph24t5v5f5q@piout.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K0:qx7+FATleIowkS9EIaBytXhzAhLtU9WZpM1053y9U8Kd/6mGvRT IDZZLzkU5YwsKwux78+pIhEJX6F3U90JVNoz91Jp+OR9+N5RPOiUWIuDWYAZeBP7GLA2A8d z9KIXK/EUk+u+TwwF1ploHBYcf9ibOnjZshdA0dAy1CkN7e4FwoUmGWOH/7+G5iMiqt24wo EMyTvfFCB1bbvk7ODV9Bg== X-UI-Out-Filterresults: notjunk:1;V01:K0:xvUQ1zd+63I=:5LhCqgbeMEaU8vn/vkAUC5 DniukiDkZfU0ooZr19cYtCbSaniZJe1A5r6Bc0g/0PIdP4FlKmwGaNTuiT241OKRb4t+PMCm+ ehuQBKlCSDjY7HPqXIsAQmouqKspJxyDLrqFsP9EZmI629OBmFcmCP5lqAK35ww7APBkfDGRE Ca8flTSvmazoXXOcwbl8Nv0B7WV1p36UrzBp7Z7HRngSdn2jnlEhRIvt2yC8m+i6xkOmYQVcm DQBTYEWDsnfj59I5wsfJgjcmDSVOTngRUrJltaPr4MFGTsyd/T8ZRpCyqwfZWPAutwbVEI0rq OrsB+xeDS5Bg+lg91HzB0n8jGkOxUAUN9QIY6xMcRSosp1fVeObImj3fMvKir/NEoIMt58dqS HCorSZqCG0vJH+VfUWb7KpOMuPj6JpD8tmUktxpJz5kO7JRLgqz6hv5hXhi/twb1DKZUk35zP sFv2MpUsLc/ynwykzerzDaZpqTikwQnO4pydievbsao2xSts4QRKTDWcNJw5xfAEj/QilcX+q PRctYDz7ONYFX8BTF2gNJek2EaoFEUW0xjMprNuYyL6tIhp0/G829I3Z3FalEUj9d8nKVG6Rp LWY36pdH2tkImsOosQTsw1CnE257/sdNDjfbyPUoYsPsAS8egfA6Xwr3RqdzPkRXKhcprfFct zLfmxfMJyHFrsY/f+HlB1teLsfOT6fr8N54Ky4CBjyHTjNQma22tRhEngOtEP+QYFrbYfv90K X1TbnRNDmWAxu6UCj0VAinSlbtu1EMOv1k46xIr9zYi0ZdC0y4/Zt2bGPLYT/bm1tzPUl3Ev7 fg7X51P Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> @@ -334,8 +334,8 @@ static int asoc_simple_card_parse_aux_devs(struct device_node *node, >> if (n <= 0) >> return -EINVAL; >> >> - card->aux_dev = devm_kzalloc(dev, >> - n * sizeof(*card->aux_dev), GFP_KERNEL); >> + card->aux_dev = devm_kcalloc(dev, n, sizeof(*card->aux_dev), >> + GFP_KERNEL); > > Do you realize that this change has absolutely no value We can have different software development opinions about such a source code adjustment. Does it improve the indentation for the parameters which are passed to this function call? > and just makes the code slower (one more test in the allocation path)? Do we stumble on a target conflict for the shown implementation detail? Does the previous size calculation contain the general possibility for an integer overflow? https://cwe.mitre.org/data/definitions/190.html The value for the variable “len” (and also “n”) might be small enough so that the computed value will usually not exceed the data type limit in this use case. Regards, Markus From mboxrd@z Thu Jan 1 00:00:00 1970 From: SF Markus Elfring Date: Fri, 28 Apr 2017 10:48:15 +0000 Subject: Re: [alsa-devel] [PATCH 1/3] ASoC: simple-card: Use devm_kcalloc() in asoc_simple_card_parse_aux_dev Message-Id: <49bbbcac-f970-bbb9-c66b-c9c25229cc6a@users.sourceforge.net> List-Id: References: <8b5e37d1-17c5-4551-801f-ca7939d5efd7@users.sourceforge.net> <8c8c6979-0368-9ef5-2e10-57199f0bc03e@users.sourceforge.net> <20170428085735.i7xpxph24t5v5f5q@piout.net> In-Reply-To: <20170428085735.i7xpxph24t5v5f5q@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Alexandre Belloni Cc: Nikita Yushchenko , alsa-devel@alsa-project.org, Kuninori Morimoto , LKML , Takashi Iwai , kernel-janitors@vger.kernel.org, Liam Girdwood , Mark Brown >> @@ -334,8 +334,8 @@ static int asoc_simple_card_parse_aux_devs(struct device_node *node, >> if (n <= 0) >> return -EINVAL; >> >> - card->aux_dev = devm_kzalloc(dev, >> - n * sizeof(*card->aux_dev), GFP_KERNEL); >> + card->aux_dev = devm_kcalloc(dev, n, sizeof(*card->aux_dev), >> + GFP_KERNEL); > > Do you realize that this change has absolutely no value We can have different software development opinions about such a source code adjustment. Does it improve the indentation for the parameters which are passed to this function call? > and just makes the code slower (one more test in the allocation path)? Do we stumble on a target conflict for the shown implementation detail? Does the previous size calculation contain the general possibility for an integer overflow? https://cwe.mitre.org/data/definitions/190.html The value for the variable “len” (and also “n”) might be small enough so that the computed value will usually not exceed the data type limit in this use case. Regards, Markus From mboxrd@z Thu Jan 1 00:00:00 1970 From: SF Markus Elfring Subject: Re: [PATCH 1/3] ASoC: simple-card: Use devm_kcalloc() in asoc_simple_card_parse_aux_devs() Date: Fri, 28 Apr 2017 12:48:15 +0200 Message-ID: <49bbbcac-f970-bbb9-c66b-c9c25229cc6a@users.sourceforge.net> References: <8b5e37d1-17c5-4551-801f-ca7939d5efd7@users.sourceforge.net> <8c8c6979-0368-9ef5-2e10-57199f0bc03e@users.sourceforge.net> <20170428085735.i7xpxph24t5v5f5q@piout.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mout.web.de (mout.web.de [212.227.15.14]) by alsa0.perex.cz (Postfix) with ESMTP id 900EB266860 for ; Fri, 28 Apr 2017 12:48:35 +0200 (CEST) In-Reply-To: <20170428085735.i7xpxph24t5v5f5q@piout.net> Content-Language: en-GB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Alexandre Belloni Cc: Nikita Yushchenko , alsa-devel@alsa-project.org, Kuninori Morimoto , LKML , Takashi Iwai , kernel-janitors@vger.kernel.org, Liam Girdwood , Mark Brown List-Id: alsa-devel@alsa-project.org Pj4gQEAgLTMzNCw4ICszMzQsOCBAQCBzdGF0aWMgaW50IGFzb2Nfc2ltcGxlX2NhcmRfcGFyc2Vf YXV4X2RldnMoc3RydWN0IGRldmljZV9ub2RlICpub2RlLAo+PiAgCWlmIChuIDw9IDApCj4+ICAJ CXJldHVybiAtRUlOVkFMOwo+PiAgCj4+IC0JY2FyZC0+YXV4X2RldiA9IGRldm1fa3phbGxvYyhk ZXYsCj4+IC0JCQluICogc2l6ZW9mKCpjYXJkLT5hdXhfZGV2KSwgR0ZQX0tFUk5FTCk7Cj4+ICsJ Y2FyZC0+YXV4X2RldiA9IGRldm1fa2NhbGxvYyhkZXYsIG4sIHNpemVvZigqY2FyZC0+YXV4X2Rl diksCj4+ICsJCQkJICAgICBHRlBfS0VSTkVMKTsKPiAKPiBEbyB5b3UgcmVhbGl6ZSB0aGF0IHRo aXMgY2hhbmdlIGhhcyBhYnNvbHV0ZWx5IG5vIHZhbHVlCgpXZSBjYW4gaGF2ZSBkaWZmZXJlbnQg c29mdHdhcmUgZGV2ZWxvcG1lbnQgb3BpbmlvbnMgYWJvdXQgc3VjaCBhIHNvdXJjZSBjb2RlIGFk anVzdG1lbnQuCkRvZXMgaXQgaW1wcm92ZSB0aGUgaW5kZW50YXRpb24gZm9yIHRoZSBwYXJhbWV0 ZXJzIHdoaWNoIGFyZSBwYXNzZWQgdG8gdGhpcyBmdW5jdGlvbiBjYWxsPwoKCj4gYW5kIGp1c3Qg bWFrZXMgdGhlIGNvZGUgc2xvd2VyIChvbmUgbW9yZSB0ZXN0IGluIHRoZSBhbGxvY2F0aW9uIHBh dGgpPwoKRG8gd2Ugc3R1bWJsZSBvbiBhIHRhcmdldCBjb25mbGljdCBmb3IgdGhlIHNob3duIGlt cGxlbWVudGF0aW9uIGRldGFpbD8KCkRvZXMgdGhlIHByZXZpb3VzIHNpemUgY2FsY3VsYXRpb24g Y29udGFpbiB0aGUgZ2VuZXJhbCBwb3NzaWJpbGl0eSBmb3IKYW4gaW50ZWdlciBvdmVyZmxvdz8K aHR0cHM6Ly9jd2UubWl0cmUub3JnL2RhdGEvZGVmaW5pdGlvbnMvMTkwLmh0bWwKClRoZSB2YWx1 ZSBmb3IgdGhlIHZhcmlhYmxlIOKAnGxlbuKAnSAoYW5kIGFsc28g4oCcbuKAnSkgbWlnaHQgYmUg c21hbGwgZW5vdWdoIHNvIHRoYXQKdGhlIGNvbXB1dGVkIHZhbHVlIHdpbGwgdXN1YWxseSBub3Qg ZXhjZWVkIHRoZSBkYXRhIHR5cGUgbGltaXQgaW4gdGhpcyB1c2UgY2FzZS4KClJlZ2FyZHMsCk1h cmt1cwpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpBbHNh LWRldmVsIG1haWxpbmcgbGlzdApBbHNhLWRldmVsQGFsc2EtcHJvamVjdC5vcmcKaHR0cDovL21h aWxtYW4uYWxzYS1wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL2Fsc2EtZGV2ZWwK