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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 9BF98CA5FD4 for ; Fri, 2 Oct 2026 17:40:15 +0000 (UTC) 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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=q0YagE8rflxUswe6sAAs865u831nLtV6oL2GHgnEg8Y=; b=nWHsQhCJTY1cI2+KdDDc8mQMWW tCpE0B0SsWiHTs+VdKXoHrgh5HJ9FxmZyAH+gerX/9psnvWVyD9r4PTFqM3lsX9TtEwV+9RBRR8Ol HxA7j3O9sMEJ8GPKspa2Dq7aaHIatDPjmovXldnSEzmKFnnhaEdm1uSy5vfCLfabmMjRiIpZwptni WzViQDHTrIGXJGZAnBtWXnOz+QtgsdxV9uqkQjsCr49WVFAT8ZRCJpQJ2HcZxFTM6DzIv6FzKliww gL7/aQ0daqsbuCyPcj3kDrGoDK5hI+3w7J/yAM1UEZbd68G7y/t6xMd9J43ZGz0zEZNQWbqVUcPEN QbMbHxxQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xChEv-0000000CBHe-0Hlu; Fri, 02 Oct 2026 17:40:09 +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 1xChEs-0000000CBF6-2pFk for linux-arm-kernel@lists.infradead.org; Fri, 02 Oct 2026 17:40:07 +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 6AC05143D; Fri, 2 Oct 2026 10:40:02 -0700 (PDT) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.2.212.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BABD33F85F; Fri, 2 Oct 2026 10:40:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790962805; bh=xHWUygO4qxy8ieQBIbBK4CiBLOdC4aiT1dsQJP56zew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e1oTxFoRmwrcbEyc1rw5GZ1G8x88W9bLnE19gRWv4cLKSx8sOXTI0dBArbpU77khG KD8en7qNFl8LYZ3iVmfcMYMnNKqUt2CwCfKFhXJBaugH1IdkfczCMDKDXb+v8/91/E rT4J7oqknePVa7f0jsT9RKLa6mFGUmUhgqVx5qkE= From: James Morse To: linux-arm-kernel@lists.infradead.org Cc: Catalin Marinas , Will Deacon , Ben Horgan , Andre Przywara , Fuad Tabba , Gavin Shan , James Morse Subject: [PATCH 04/27] arm_mpam: Add missing mon_sel locking in MBWU save and restore Date: Fri, 2 Oct 2026 18:39:17 +0100 Message-ID: <20261002173941.292319-5-james.morse@arm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261002173941.292319-1-james.morse@arm.com> References: <20261002173941.292319-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261002_104006_806245_0837D3CA X-CRM114-Status: GOOD ( 13.28 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Ben Horgan The mon_sel_lock is used to protect the mbwu_state, as well as h/w accesses that use MPAMCFG_MON_SEL. However, in mpam_restore/save_mbwu_state(), mbwu_state is accessed without holding the mon_sel_lock. Add the missing locking. Fixes: 41e8a14950e1 ("arm_mpam: Track bandwidth counter state for power management") Signed-off-by: Ben Horgan Tested-by: Gavin Shan Reviewed-by: Gavin Shan Reviewed-by: James Morse Signed-off-by: James Morse --- drivers/resctrl/mpam_devices.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index e349db525882..d39d210574a6 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1652,17 +1652,26 @@ static int mpam_restore_mbwu_state(void *_ris) u64 val; struct mon_read mwbu_arg; struct mpam_msc_ris *ris = _ris; + struct mpam_msc *msc = ris->vmsc->msc; struct mpam_class *class = ris->vmsc->comp->class; for (i = 0; i < ris->props.num_mbwu_mon; i++) { - if (ris->mbwu_state[i].enabled) { - mwbu_arg.ris = ris; - mwbu_arg.ctx = &ris->mbwu_state[i].cfg; - mwbu_arg.type = mpam_msmon_choose_counter(class); - mwbu_arg.val = &val; + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + return -EIO; - __ris_msmon_read(&mwbu_arg); + if (!ris->mbwu_state[i].enabled) { + mpam_mon_sel_unlock(msc); + continue; } + + mwbu_arg.ris = ris; + mwbu_arg.ctx = &ris->mbwu_state[i].cfg; + mwbu_arg.type = mpam_msmon_choose_counter(class); + mwbu_arg.val = &val; + + mpam_mon_sel_unlock(msc); + + __ris_msmon_read(&mwbu_arg); } return 0; @@ -1680,12 +1689,12 @@ static int mpam_save_mbwu_state(void *arg) struct mpam_msc *msc = ris->vmsc->msc; for (i = 0; i < ris->props.num_mbwu_mon; i++) { + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + return -EIO; + mbwu_state = &ris->mbwu_state[i]; cfg = &mbwu_state->cfg; - if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) - return -EIO; - mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) | FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); -- 2.53.0