From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792573300; b=AMiB1B9mehZslT/nUiA+CVKc0kxJxAsIPGg8ZDG6Dggpt1rXgxhD3qiRiarhQy1/arXB 5bTdjtG3GitK/a7I849zktjxeXH0f1hOYj2ACqNPPZF7pPzZxVXMLPbXMpVYhk5R6jp/g o8H4l1Jcmkaht+qRon85LeTFRjMHA16q4mATvpN9Tnu5h7abLAvhXNUWZFR6MoL72Adoy 3BoPf9SKy7Ev1mPIFWTRBdlPMdazk/CnmM70pN+l69dXyVe/GIkgA13+hJ28ADimHSrh/ NgwGolmTUJAw9lG1XJeBytzIcRWYvalknBmxmKrO9HIaa7SzZCh8+vAWvzKZ4Py7yRw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792573300; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=ZIYBFbjC/JqHo0qDK7NxuyTwTfuFB9bR24RyXwEbtJw=; b=gW+nDrGRKKLVnhZSopUesO+68LQYsg+GilqM4MYhdrqr2Cz6ELhAgD+3y7ggG4CNyovo ZFgxAnJy9T0atK5ZbJm8wLtViSp+0TxGR9IvyWDub79FLH41JgK38WUtrm1sIlfNeL9I6 KOJjjydth5IqRqKYU72B0hhdmhrkVpCbXDYTSTIE6kPWQscves0fRuLbsfFZQ53MmZ88X IkJyGwGkvfxa7GAQa6osIvvrSQfdgQ/I7RSLqxRpNyYESt6IoMeR5tHdYwyipQNI3KtCr KWexYOwKlFhKURt+L2HiqtVb/rOVvP6g4PmHUPL0T3iWoquxHl8qiV6TmKcQa3u9S9Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=CtwAc54H; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EEA4A606A31D for ; Wed, 21 Oct 2026 09:01:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org EEA4A606A31D Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=CtwAc54H 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-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list 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 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