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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FFF6C433EF for ; Mon, 1 Nov 2021 06:15:33 +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 5E5FD61077 for ; Mon, 1 Nov 2021 06:15:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5E5FD61077 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:CC:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=SjzJcEZVCU19JP8//9IVUQSZFt2wCJa1aZXnx5m1x0k=; b=eaV8gPHtoSWjGH 6pUMeWjQAtfLRpfkrPdgtCv6yBQGiRPuQE1IS5zzPHAK4GMV3GsXWJulUzz88Ug4IurPHgTzeOjGs 1m9LXUBKTIh7/oCwdh0/LmfjoysBUUsKhEMiD90LEuAhA9WeI9nl07pkPqkN3hOsEA7ZUOT975vga j6KfilwTchafPz3VQbWVNRUNFp3y+p567kEoPqD6ezLCauu+KuQqyvvMoEXuWGWzDqoK4RjI98717 8Y558/wLGYySog6LvwBg/3YQ6EAUz18an3kRziXo3r8o4sCBby4MTa+okswnvSfRAN74iTGLkJDSg nFGmfd8fTYUrPRq/qqjg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mhQZu-00FQTS-6H; Mon, 01 Nov 2021 06:13:54 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mhQZn-00FQRg-Ol; Mon, 01 Nov 2021 06:13:50 +0000 X-UUID: e0f2c82914684ba5b70ed54fcae5cf80-20211031 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:MIME-Version:Content-Type:References:In-Reply-To:Date:CC:To:From:Subject:Message-ID; bh=xVKTQc7OPGqCgUqaW4iGQjm4T5FKiIv77uCXhzrHMa4=; b=CRD3SrYzD9KnCvotD60fVLwRPs3gABLwpazhe5BwqAmJyFapMvlYpLvVOGELXnh6zrk+lwEdVzAjoyzad/Lh9QX5ulwJQj9r82SYlNWBeTTS1GfRXcodE2LuyXlqO/NI7Rexm1xpFprvhmMzohJuaFaDLDI1/SBfYa/zfPHdaJw=; X-UUID: e0f2c82914684ba5b70ed54fcae5cf80-20211031 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 364850643; Sun, 31 Oct 2021 23:13:41 -0700 Received: from mtkmbs10n2.mediatek.inc (172.21.101.183) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sun, 31 Oct 2021 23:09:17 -0700 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Mon, 1 Nov 2021 14:09:15 +0800 Received: from mhfsdcap04 (10.17.3.154) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 1 Nov 2021 14:09:14 +0800 Message-ID: <9e4f327511fd85ba8613ec27644fbc29bc4ddb6b.camel@mediatek.com> Subject: Re: [PATCH] memory: mtk-smi: Fix a null dereference for the ostd From: Yong Wu To: Krzysztof Kozlowski CC: Krzysztof Kozlowski , Joerg Roedel , Will Deacon , Robin Murphy , "Tomasz Figa" , , , , , , , , , , Ikjoon Jang , "Matthias Brugger" Date: Mon, 1 Nov 2021 14:09:14 +0800 In-Reply-To: <23b036d1-bdc4-da55-a800-03fc3dabd48e@canonical.com> References: <20211028055056.26378-1-yong.wu@mediatek.com> <23b036d1-bdc4-da55-a800-03fc3dabd48e@canonical.com> X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211031_231347_833947_2C6F196C X-CRM114-Status: GOOD ( 31.31 ) X-BeenThere: linux-arm-kernel@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="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 2021-10-29 at 19:35 +0200, Krzysztof Kozlowski wrote: > On 28/10/2021 07:50, Yong Wu wrote: > > We add the ostd setting for mt8195. It introduces a abort for the > > previous SoC which doesn't have ostd setting. This is the log: > > > > Unable to handle kernel NULL pointer dereference at virtual address > > 0000000000000080 > > ... > > pc : mtk_smi_larb_config_port_gen2_general+0x64/0x130 > > lr : mtk_smi_larb_resume+0x54/0x98 > > ... > > Call trace: > > mtk_smi_larb_config_port_gen2_general+0x64/0x130 > > pm_generic_runtime_resume+0x2c/0x48 > > __genpd_runtime_resume+0x30/0xa8 > > genpd_runtime_resume+0x94/0x2c8 > > __rpm_callback+0x44/0x150 > > rpm_callback+0x6c/0x78 > > rpm_resume+0x310/0x558 > > __pm_runtime_resume+0x3c/0x88 > > > > In the code: larbostd = larb->larb_gen->ostd[larb->larbid], > > if "larb->larb_gen->ostd" is null, the "larbostd" is the offset, it > > is > > also a valid value, thus, use the larb->larb_gen->ostd as the > > condition > > inside the "for" loop. > > You need to write more clearly, what you are fixing here. > > > > > Signed-off-by: Yong Wu > > --- > > Hi Krzysztof, > > Could you help review and conside this as a fix for the mt8195 > > patchset? > > The mt8195 patchset are not in mainline, thus, I don't know its > > sha-id, > > and don't add Fixes tag. > > Thanks > > --- > > drivers/memory/mtk-smi.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c > > index b883dcc0bbfa..0262a59a2d6e 100644 > > --- a/drivers/memory/mtk-smi.c > > +++ b/drivers/memory/mtk-smi.c > > @@ -257,7 +257,7 @@ static void > > mtk_smi_larb_config_port_gen2_general(struct device *dev) > > if (MTK_SMI_CAPS(flags_general, MTK_SMI_FLAG_SW_FLAG)) > > writel_relaxed(SMI_LARB_SW_FLAG_1, larb->base + > > SMI_LARB_SW_FLAG); > > > > - for (i = 0; i < SMI_LARB_PORT_NR_MAX && larbostd && > > !!larbostd[i]; i++) > > + for (i = 0; i < SMI_LARB_PORT_NR_MAX && larb->larb_gen->ostd && > > !!larbostd[i]; i++) > > writel_relaxed(larbostd[i], larb->base + > > SMI_LARB_OSTDL_PORTx(i)); > > The code does not look good. You have already a dereference at line > 244: > > const u8 *larbostd = larb->larb_gen->ostd[larb->larbid]; if larb->larb_gen->ostd is null, larbostd is the offset, e.g. 0x80 in the log above. thus, we can not use "larbostd[i]" in the "for" loop. sorry for the unreadable. In this case, is the change ok? or like this: -const u8 *larbostd = larb->larb_gen->ostd[larb->larbid]; +const u8 *larbostd = larb->larb_gen->ostd ? larb->larb_gen-ostd[larb- >larbid] : NULL; or add a explicit "if": if (larb->larb_gen->ostd) larbostd = xxx. Which one do you prefer? Thanks. > > You are not fixing the NULL pointer dereference. > > > > > for_each_set_bit(i, (unsigned long *)larb->mmu, 32) { > > > > > Best regards, > Krzysztof _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel