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 X-Spam-Level: X-Spam-Status: No, score=-15.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4683C47089 for ; Thu, 27 May 2021 15:05:06 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 67DE46128D for ; Thu, 27 May 2021 15:05:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 67DE46128D Authentication-Results: mail.kernel.org; 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x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210527_074104_430728_F71CAB3A X-CRM114-Status: GOOD ( 24.03 ) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org SGkgWWFuZywKCllhbmcgWWluZ2xpYW5nIDx5YW5neWluZ2xpYW5nQGh1YXdlaS5jb20+IHdyb3Rl IG9uIFRodSwgMjcgTWF5IDIwMjEKMjE6NDk6NTMgKzA4MDA6Cgo+IEhpLAo+IAo+IE9uIDIwMjEv NS8yNyAxODowMSwgTWlxdWVsIFJheW5hbCB3cm90ZToKPiA+IEhpIFlhbmcsCj4gPgo+ID4gWWFu ZyBZaW5nbGlhbmcgPHlhbmd5aW5nbGlhbmdAaHVhd2VpLmNvbT4gd3JvdGUgb24gVHVlLCAxOCBN YXkgMjAyMQo+ID4gMjE6MTE6MjcgKzA4MDA6Cj4gPiAgCj4gPj4gaXJxIGFsbG9jYXRlZCB3aXRo IGRldm1fcmVxdWVzdF9pcnEgc2hvdWxkIG5vdCBiZSBmcmVlZCB1c2luZwo+ID4+IGZyZWVfaXJx LCBiZWNhdXNlIGRvaW5nIHNvIGNhdXNlcyBhIGRhbmdsaW5nIHBvaW50ZXIsIGFuZCBhCj4gPj4g c3Vic2VxdWVudCBkb3VibGUgZnJlZS4KPiA+Pgo+ID4+IFJlcG9ydGVkLWJ5OiBIdWxrIFJvYm90 IDxodWxrY2lAaHVhd2VpLmNvbT4KPiA+PiBTaWduZWQtb2ZmLWJ5OiBZYW5nIFlpbmdsaWFuZyA8 eWFuZ3lpbmdsaWFuZ0BodWF3ZWkuY29tPgo+ID4+IC0tLQo+ID4+ICAgZHJpdmVycy9pM2MvbWFz dGVyL3N2Yy1pM2MtbWFzdGVyLmMgfCAyICstCj4gPj4gICAxIGZpbGUgY2hhbmdlZCwgMSBpbnNl cnRpb24oKyksIDEgZGVsZXRpb24oLSkKPiA+Pgo+ID4+IGRpZmYgLS1naXQgYS9kcml2ZXJzL2kz Yy9tYXN0ZXIvc3ZjLWkzYy1tYXN0ZXIuYyBiL2RyaXZlcnMvaTNjL21hc3Rlci9zdmMtaTNjLW1h c3Rlci5jCj4gPj4gaW5kZXggMWY2YmE0MjIxODE3Li43NjFjOWM0NjgzNTcgMTAwNjQ0Cj4gPj4g LS0tIGEvZHJpdmVycy9pM2MvbWFzdGVyL3N2Yy1pM2MtbWFzdGVyLmMKPiA+PiArKysgYi9kcml2 ZXJzL2kzYy9tYXN0ZXIvc3ZjLWkzYy1tYXN0ZXIuYwo+ID4+IEBAIC0xNDQ4LDcgKzE0NDgsNyBA QCBzdGF0aWMgaW50IHN2Y19pM2NfbWFzdGVyX3JlbW92ZShzdHJ1Y3QgcGxhdGZvcm1fZGV2aWNl ICpwZGV2KQo+ID4+ICAgCWlmIChyZXQpCj4gPj4gICAJCXJldHVybiByZXQ7ICAKPiA+PiAgID4+ IC0JZnJlZV9pcnEobWFzdGVyLT5pcnEsIG1hc3Rlcik7ICAKPiA+PiArCWRldm1fZnJlZV9pcnEo JnBkZXYtPmRldiwgbWFzdGVyLT5pcnEsIG1hc3Rlcik7ICAKPiA+IFdvdWxkbid0IHJlbW92aW5n IHRoaXMgY2FsbCB0aGUgcmlnaHQgc29sdXRpb24/IElmIGl0J3MgYSBkZXZpY2UKPiA+IG1hbmFn ZWQgcmVzb3VyY2UsIGl0IHdvbid0IHByb2JhYmx5IGJlIG5lZWRlZCB0byBmcmVlIGl0IGV4cGxp Y2l0bHkgaW4KPiA+IHRoZSByZW1vdmUgcGF0aC4gIAo+IFNvbWUgZHJpdmVycyB3b3VsZCBleHBl Y3QgdG8gZnJlZSBpcnEgaXRzZWxmLAoKSSBkb24ndCBnZXQgaXQuIERyaXZlcnMgZG8gbm90IGV4 cGVjdCBhbnl0aGluZywgdGhleSBzaG91bGQganVzdCBjb21wbHkKd2l0aCB0aGUgQVBJLiBJZiBy b2JvdHMgY29tcGxhaW4gYmVjYXVzZSBhIGRldmljZSBtYW5hZ2VkIHJlc291cmNlIGlzCmJlaW5n IGZyZWVkIHdpdGhvdXQgdGhlIGRldmljZSBtYW5hZ2VkIGhlbHBlciwgdGhpcyBkb2VzIG5vdCBt ZWFuIHRoYXQKdGhlIHJlc291cmNlIHNob3VsZCBleHBsaWNpdGx5IGJlIGZyZWVkLCBpdCBqdXN0 IG1lYW5zIHRoYXQgKmlmKiBpdAptdXN0IGJlIGV4cGxpY2l0bHkgZnJlZWQsIHRoZSB3cm9uZyBo ZWxwZXIgaXMgYmVpbmcgdXNlZC4KCj4gSSBhbSBub3Qgc3VyZSBpZiBpdCdzIG9rIHRvIHJlbW92 ZSB0aGUgZnJlZV9pcnEoKSBpbiBpM2MsCgpXaGF0IGlzIHRoZSBsaW5rIHdpdGggSTNDPyBTb3Jy eSBJIG1pZ2h0IGJlIG1pc3Npbmcgc29tZXRoaW5nIGJ1dAptYXN0ZXItPmlycSBpcyBhIGRyaXZl ciB2YXJpYWJsZSwgSSBkb24ndCBnZXQgdGhlIGxpbmsgd2l0aCB0aGUgSTNDCmZyYW1ld29yayBh bmQgd2h5IGl0IHdvdWxkIGludGVyZmVyZS4KCj4gSSBqdXN0IGtlZXAgdGhlIG9yaWdpbmFsIGxv Z2ljIGhlcmUgYW5kIGF2b2lkIGRvdWJsZSBmcmVlLgoKSSBkb24ndCB0aGluayBpdCBpcyBzYW5l LiBDYWxsaW5nIGRldm1fZnJlZV9pcnEoKSBtYXliZSBpcyB0aGUgcmlnaHQKc29sdXRpb24gLSBJ IGRvbid0IGZlZWwgbGlrZSBpdCBpcyAtIGJ1dCB5b3VyIGNlcnRhaW5seSBjYW4ndCBoaWRlCmJl aGluZCBhICdJIGp1c3Qgd2FudCB0aGUgcm9ib3RzIHRvIGJlIGhhcHB5JyBqdXN0aWZpY2F0aW9u LiBIaWRpbmcKYnVncyBvbiBwdXJwb3NlIGlzIG5vdCBzb21ldGhpbmcgdGhhdCBJIHBlcnNvbmFs bHkgYXBwcmVjaWF0ZSBtdWNoLgoKVGhhbmtzLApNaXF1w6hsCgotLSAKbGludXgtaTNjIG1haWxp bmcgbGlzdApsaW51eC1pM2NAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFk ZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LWkzYwo= 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 X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C61AC47089 for ; Thu, 27 May 2021 14:41:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8044360249 for ; Thu, 27 May 2021 14:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234629AbhE0Omf convert rfc822-to-8bit (ORCPT ); Thu, 27 May 2021 10:42:35 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:42149 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229769AbhE0Ome (ORCPT ); Thu, 27 May 2021 10:42:34 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 4E33C100006; Thu, 27 May 2021 14:40:59 +0000 (UTC) Date: Thu, 27 May 2021 16:40:58 +0200 From: Miquel Raynal To: Yang Yingliang Cc: , , Subject: Re: [PATCH -next] i3c: master: svc: drop free_irq of devm_request_irq allocated irq Message-ID: <20210527164058.3c9145b2@xps13> In-Reply-To: <7052d19a-54cb-d634-f195-dbd8ef37f1e7@huawei.com> References: <20210518131127.1308550-1-yangyingliang@huawei.com> <20210527120123.75f2ea09@xps13> <7052d19a-54cb-d634-f195-dbd8ef37f1e7@huawei.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yang, Yang Yingliang wrote on Thu, 27 May 2021 21:49:53 +0800: > Hi, > > On 2021/5/27 18:01, Miquel Raynal wrote: > > Hi Yang, > > > > Yang Yingliang wrote on Tue, 18 May 2021 > > 21:11:27 +0800: > > > >> irq allocated with devm_request_irq should not be freed using > >> free_irq, because doing so causes a dangling pointer, and a > >> subsequent double free. > >> > >> Reported-by: Hulk Robot > >> Signed-off-by: Yang Yingliang > >> --- > >> drivers/i3c/master/svc-i3c-master.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c > >> index 1f6ba4221817..761c9c468357 100644 > >> --- a/drivers/i3c/master/svc-i3c-master.c > >> +++ b/drivers/i3c/master/svc-i3c-master.c > >> @@ -1448,7 +1448,7 @@ static int svc_i3c_master_remove(struct platform_device *pdev) > >> if (ret) > >> return ret; > >> >> - free_irq(master->irq, master); > >> + devm_free_irq(&pdev->dev, master->irq, master); > > Wouldn't removing this call the right solution? If it's a device > > managed resource, it won't probably be needed to free it explicitly in > > the remove path. > Some drivers would expect to free irq itself, I don't get it. Drivers do not expect anything, they should just comply with the API. If robots complain because a device managed resource is being freed without the device managed helper, this does not mean that the resource should explicitly be freed, it just means that *if* it must be explicitly freed, the wrong helper is being used. > I am not sure if it's ok to remove the free_irq() in i3c, What is the link with I3C? Sorry I might be missing something but master->irq is a driver variable, I don't get the link with the I3C framework and why it would interfere. > I just keep the original logic here and avoid double free. I don't think it is sane. Calling devm_free_irq() maybe is the right solution - I don't feel like it is - but your certainly can't hide behind a 'I just want the robots to be happy' justification. Hiding bugs on purpose is not something that I personally appreciate much. Thanks, Miquèl