From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D9C85606A31B for ; Wed, 21 Oct 2026 09:02:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=ZRzHyx0u; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=CtwAc54H DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ZIYBFbjC/JqHo0qDK7NxuyTwTfuFB9bR24RyXwEbtJw=; b=ZRzHyx0umWFPpfV2R3htuV4Pjm 6jCOWTBK+bkyWFPupPmDDbP7upJfTOPb0Nt+uw6em5SFhHY9hRfh97TCeQ6gwFIX0h/0185HfRdhk bbTorzmeFz6E2WfyXEMGNGq4d9P6epjOI6atlMI6kfW6xg9QNCWvo1UamRCNrEuX9h1V5EiYO/lIu /CXoeb4zE/tGVx+vcu+aTzRFiwIvkOCu6UBO4aeF3+8LM9fRj23wylqiMKhyIFOjUqFhDg1RW6hIO cNjoZRVfiMVODbqqYwroaCO/isyDchWjn2dpyZkGAke1VJbEZehYA6zSJv415aJmxDiXydsrKH0bY rlSQqFBA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJSCg-0000000BQOe-0pxp; Wed, 21 Oct 2026 09:01:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJSCd-0000000BQOE-1Ha2 for linux-arm-kernel@lists.infradead.org; Wed, 21 Oct 2026 09:01:44 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1898C1476; Wed, 21 Oct 2026 02:01:36 -0700 (PDT) Received: from [10.2.212.8] (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 423013F7B4; Wed, 21 Oct 2026 02:01:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1792573299; bh=IF9maRMh0ugYhaWVRkx0qEpMGhQizVGkaK12H+FqOb4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=CtwAc54HU8054fUIqwxPvGqgDv1y8BiPTMukHE8vK7E3wsJAPqkZVb4s19U8s5WyL r/cDYTKzp2qSTXixDwHCWkXzNrV/0xX0IUGLysYCa7DlSmdDe8MrLQRXs5LWaik5Pa /thsOstjqTY2LxEUh1k4dkl8p/uYx8Q1VSfnYMrQ= Message-ID: Date: Wed, 21 Oct 2026 10:01:36 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm_mpam: Release the mon_sel lock on mpam_save_mbwu_state() errors To: Ping Li , james.morse@arm.com Cc: andre.przywara@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, reinette.chatre@intel.com, fenghuay@nvidia.com References: <20261020114807.3915705-1-leeonion.muyu@gmail.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20261020114807.3915705-1-leeonion.muyu@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261021_020143_415717_528B6338 X-CRM114-Status: GOOD ( 18.63 ) X-Spam-Score: -4.4 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hi Ping, On 20/10/2026 12:48, Ping Li wrote: > mpam_save_mbwu_state() takes the mon_sel lock at the top of each loop > iteration, but the four error paths that return after failed > MPAMF_MON_SEL register accesses do so without releasing it. > > Take the lock with the conditional mon_sel_lock guard class instead, > so all exit paths release it. > > Fixes: a3a94c13c442 ("arm_mpam: propagate MSC access errors for state saving function") > Signed-off-by: Ping Li Thanks for this. Looks like this was a result of the conflict between the MPAM-Fb series and my minor fixes series. Reviewed-by: Ben Horgan Cheers, Ben > --- > drivers/resctrl/mpam_devices.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index 48adc49b833c..c067b6d57d71 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -2037,8 +2037,10 @@ static int mpam_save_mbwu_state(void *arg) > struct mpam_class *class = ris->vmsc->comp->class; > > for (i = 0; i < ris->props.num_mbwu_mon; i++) { > - if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) > - return -EIO; > + ACQUIRE(mon_sel_lock, guard)(msc); > + ret = ACQUIRE_ERR(mon_sel_lock, &guard); > + if (ret) > + return ret; > > mbwu_state = &ris->mbwu_state[i]; > cfg = &mbwu_state->cfg; > @@ -2061,10 +2063,8 @@ static int mpam_save_mbwu_state(void *arg) > cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt); > mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl); > > - if (!mbwu_state->enabled) { > - mpam_mon_sel_unlock(msc); > + if (!mbwu_state->enabled) > continue; > - } > > val = 0; > mbwu_arg = (struct mon_read) { > @@ -2088,8 +2088,6 @@ static int mpam_save_mbwu_state(void *arg) > ret = mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); > if (ret) > return ret; > - > - mpam_mon_sel_unlock(msc); > } > > return 0; > > base-commit: 8ea457f746d915d55f78b43d33b1cd618f3d93ad