From nobody Thu Dec 18 02:27:52 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8E0D827A44E for ; Wed, 14 May 2025 16:20:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747239606; cv=none; b=oP+oE7BL5ZV7Sw/G5wMaf98umJQWaVGAiNqqdkaDeGV6cvmoQMT104ruozISWWjKOkjEi7NREC3cH9n+4VRlMRCVc3YcdnK+w9Q1kum+5XEA5ammjGNEIPJSCo6VFTD7e6pt4+6MB6+Jd1IHfv5LrWbf6gnO7lN6+SD0IPziTz0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747239606; c=relaxed/simple; bh=GjB0bfqhUj1DgxPVr876GZC1RBk/GArqU8FS0b8NG7w=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Wz0sKU+AV54FQe42zXI1L4I3Tl+jwBFaIN6J9SQr3VmXG7RPWHAnxtyQ9enizcTsRWW6jicyLfiKFlc1VwcXe8l4m8XZsbdKut3DMmp905EpGWQFVI/ofugB91gX4mZSP1IJECTeUaefOJ7AQKDQX/BvQQ72p8pWJKhAGuXxZhY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 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 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 66E5A150C; Wed, 14 May 2025 09:19:52 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5191A3F63F; Wed, 14 May 2025 09:20:02 -0700 (PDT) From: Yeoreum Yun To: suzuki.poulose@arm.com, mike.leach@linaro.org, james.clark@linaro.org, alexander.shishkin@linux.intel.com, leo.yan@arm.com Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Yeoreum Yun Subject: [PATCH v6 2/3] coresight: holding cscfg_csdev_lock while removing cscfg from csdev Date: Wed, 14 May 2025 17:19:50 +0100 Message-Id: <20250514161951.3427590-3-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250514161951.3427590-1-yeoreum.yun@arm.com> References: <20250514161951.3427590-1-yeoreum.yun@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" There'll be possible race scenario for coresight config: CPU0 CPU1 (perf enable) load module cscfg_load_config_sets() activate config. // sysfs (sys_active_cnt =3D=3D 1) ... cscfg_csdev_enable_active_config() lock(csdev->cscfg_csdev_lock) deactivate config // sysfs (sys_activec_cnt =3D=3D 0) cscfg_unload_config_sets() cscfg_remove_owned_csdev_conf= igs() // here load config activate by CPU1 unlock(csdev->cscfg_csdev_lock) iterating config_csdev_list could be raced with config_csdev_list's entry delete. To resolve this race , hold csdev->cscfg_csdev_lock() while cscfg_remove_owned_csdev_configs() Fixes: 02bd588e12df ("coresight: configuration: Update API to permit dynami= c load/unload") Signed-off-by: Yeoreum Yun Reviewed-by: Leo Yan --- drivers/hwtracing/coresight/coresight-syscfg.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtra= cing/coresight/coresight-syscfg.c index a70c1454b410..23017612f2ea 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -395,6 +395,8 @@ static void cscfg_remove_owned_csdev_configs(struct cor= esight_device *csdev, voi if (list_empty(&csdev->config_csdev_list)) return; =20 + guard(raw_spinlock_irqsave)(&csdev->cscfg_csdev_lock); + list_for_each_entry_safe(config_csdev, tmp, &csdev->config_csdev_list, no= de) { if (config_csdev->config_desc->load_owner =3D=3D load_owner) list_del(&config_csdev->node); --=20 LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}