From nobody Tue Dec 16 19:56:40 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA630C001E0 for ; Sat, 21 Oct 2023 08:40:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230419AbjJUIiN (ORCPT ); Sat, 21 Oct 2023 04:38:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230442AbjJUIiJ (ORCPT ); Sat, 21 Oct 2023 04:38:09 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81143D55 for ; Sat, 21 Oct 2023 01:38:03 -0700 (PDT) Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4SCF9D6BBTzNp0d; Sat, 21 Oct 2023 16:33:52 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Sat, 21 Oct 2023 16:37:53 +0800 From: Junhao He To: , CC: , , , , , , , Subject: [PATCH v2 1/4] coresight: ultrasoc-smb: Fix sleep while close preempt in enable_smb Date: Sat, 21 Oct 2023 16:38:19 +0800 Message-ID: <20231021083822.18239-2-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231021083822.18239-1-hejunhao3@huawei.com> References: <20231021083822.18239-1-hejunhao3@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When we to enable the SMB by perf, the perf sched will call perf_ctx_lock() to close system preempt in event_function_call(). But SMB::enable_smb() use mutex to lock the critical section, which may sleep. BUG: sleeping function called from invalid context at kernel/locking/mutex= .c:580 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 153023, name: perf preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [] copy_process+0xae8/0x2= b48 softirqs last enabled at (0): [] copy_process+0xae8/0x2= b48 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 2 PID: 153023 Comm: perf Kdump: loaded Tainted: G W O 6.5.0-rc4+= #1 Call trace: ... __mutex_lock+0xbc/0xa70 mutex_lock_nested+0x34/0x48 smb_update_buffer+0x58/0x360 [ultrasoc_smb] etm_event_stop+0x204/0x2d8 [coresight] etm_event_del+0x1c/0x30 [coresight] event_sched_out+0x17c/0x3b8 group_sched_out.part.0+0x5c/0x208 __perf_event_disable+0x15c/0x210 event_function+0xe0/0x230 remote_function+0xb4/0xe8 generic_exec_single+0x160/0x268 smp_call_function_single+0x20c/0x2a0 event_function_call+0x20c/0x220 _perf_event_disable+0x5c/0x90 perf_event_for_each_child+0x58/0xc0 _perf_ioctl+0x34c/0x1250 perf_ioctl+0x64/0x98 ... Use spinlock to replace mutex to control driver data access to one at a time. The function copy_to_user() may sleep, it cannot be in a spinlock context, so we can't simply replace it in smb_read(). But we can ensure that only one user gets the SMB device fd by smb_open(), so remove the locks from smb_read() and buffer synchronization is guaranteed by the user. Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer = driver") Signed-off-by: Junhao He --- drivers/hwtracing/coresight/ultrasoc-smb.c | 35 +++++++++------------- drivers/hwtracing/coresight/ultrasoc-smb.h | 6 ++-- 2 files changed, 17 insertions(+), 24 deletions(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing= /coresight/ultrasoc-smb.c index e9a32a97fbee..0a0fe9fcc57f 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -99,7 +99,7 @@ static int smb_open(struct inode *inode, struct file *fil= e) struct smb_drv_data, miscdev); int ret =3D 0; =20 - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); =20 if (drvdata->reading) { ret =3D -EBUSY; @@ -115,7 +115,7 @@ static int smb_open(struct inode *inode, struct file *f= ile) =20 drvdata->reading =3D true; out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); =20 return ret; } @@ -132,10 +132,8 @@ static ssize_t smb_read(struct file *file, char __user= *data, size_t len, if (!len) return 0; =20 - mutex_lock(&drvdata->mutex); - if (!sdb->data_size) - goto out; + return 0; =20 to_copy =3D min(sdb->data_size, len); =20 @@ -145,20 +143,15 @@ static ssize_t smb_read(struct file *file, char __use= r *data, size_t len, =20 if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) { dev_dbg(dev, "Failed to copy data to user\n"); - to_copy =3D -EFAULT; - goto out; + return -EFAULT; } =20 *ppos +=3D to_copy; - smb_update_read_ptr(drvdata, to_copy); - - dev_dbg(dev, "%zu bytes copied\n", to_copy); -out: if (!sdb->data_size) smb_reset_buffer(drvdata); - mutex_unlock(&drvdata->mutex); =20 + dev_dbg(dev, "%zu bytes copied\n", to_copy); return to_copy; } =20 @@ -167,9 +160,9 @@ static int smb_release(struct inode *inode, struct file= *file) struct smb_drv_data *drvdata =3D container_of(file->private_data, struct smb_drv_data, miscdev); =20 - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); drvdata->reading =3D false; - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); =20 return 0; } @@ -262,7 +255,7 @@ static int smb_enable(struct coresight_device *csdev, e= num cs_mode mode, struct smb_drv_data *drvdata =3D dev_get_drvdata(csdev->dev.parent); int ret =3D 0; =20 - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); =20 /* Do nothing, the trace data is reading by other interface now */ if (drvdata->reading) { @@ -294,7 +287,7 @@ static int smb_enable(struct coresight_device *csdev, e= num cs_mode mode, =20 dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); =20 return ret; } @@ -304,7 +297,7 @@ static int smb_disable(struct coresight_device *csdev) struct smb_drv_data *drvdata =3D dev_get_drvdata(csdev->dev.parent); int ret =3D 0; =20 - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); =20 if (drvdata->reading) { ret =3D -EBUSY; @@ -327,7 +320,7 @@ static int smb_disable(struct coresight_device *csdev) =20 dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); =20 return ret; } @@ -408,7 +401,7 @@ static unsigned long smb_update_buffer(struct coresight= _device *csdev, if (!buf) return 0; =20 - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); =20 /* Don't do anything if another tracer is using this sink. */ if (atomic_read(&csdev->refcnt) !=3D 1) @@ -432,7 +425,7 @@ static unsigned long smb_update_buffer(struct coresight= _device *csdev, if (!buf->snapshot && lost) perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); =20 return data_size; } @@ -590,7 +583,7 @@ static int smb_probe(struct platform_device *pdev) return ret; } =20 - mutex_init(&drvdata->mutex); + spin_lock_init(&drvdata->spinlock); drvdata->pid =3D -1; =20 ret =3D smb_register_sink(pdev, drvdata); diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.h b/drivers/hwtracing= /coresight/ultrasoc-smb.h index d2e14e8d2c8a..82a44c14a882 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.h +++ b/drivers/hwtracing/coresight/ultrasoc-smb.h @@ -8,7 +8,7 @@ #define _ULTRASOC_SMB_H =20 #include -#include +#include =20 /* Offset of SMB global registers */ #define SMB_GLB_CFG_REG 0x00 @@ -105,7 +105,7 @@ struct smb_data_buffer { * @csdev: Component vitals needed by the framework. * @sdb: Data buffer for SMB. * @miscdev: Specifics to handle "/dev/xyz.smb" entry. - * @mutex: Control data access to one at a time. + * @spinlock: Control data access to one at a time. * @reading: Synchronise user space access to SMB buffer. * @pid: Process ID of the process being monitored by the * session that is using this component. @@ -116,7 +116,7 @@ struct smb_drv_data { struct coresight_device *csdev; struct smb_data_buffer sdb; struct miscdevice miscdev; - struct mutex mutex; + spinlock_t spinlock; bool reading; pid_t pid; enum cs_mode mode; --=20 2.33.0 From nobody Tue Dec 16 19:56:40 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EABDEC0032E for ; Sat, 21 Oct 2023 08:40:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230257AbjJUIiG (ORCPT ); Sat, 21 Oct 2023 04:38:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229980AbjJUIiB (ORCPT ); Sat, 21 Oct 2023 04:38:01 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A3E11A8 for ; Sat, 21 Oct 2023 01:37:59 -0700 (PDT) Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4SCFBg1mhfz15NTT; Sat, 21 Oct 2023 16:35:07 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Sat, 21 Oct 2023 16:37:53 +0800 From: Junhao He To: , CC: , , , , , , , Subject: [PATCH v2 2/4] coresight: ultrasoc-smb: Config SMB buffer before register sink Date: Sat, 21 Oct 2023 16:38:20 +0800 Message-ID: <20231021083822.18239-3-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231021083822.18239-1-hejunhao3@huawei.com> References: <20231021083822.18239-1-hejunhao3@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The SMB dirver register the enable/disable sysfs interface in function smb_register_sink(), however the buffer depends on the following configuration to work well. So it'll be possible for user to access an unreset one. Move the config buffer operation to before register_sink(). Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer = driver") Signed-off-by: Junhao He --- drivers/hwtracing/coresight/ultrasoc-smb.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing= /coresight/ultrasoc-smb.c index 0a0fe9fcc57f..c61450f74cb1 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -583,38 +583,31 @@ static int smb_probe(struct platform_device *pdev) return ret; } =20 + ret =3D smb_config_inport(dev, true); + if (ret) + return ret; + + platform_set_drvdata(pdev, drvdata); spin_lock_init(&drvdata->spinlock); drvdata->pid =3D -1; =20 ret =3D smb_register_sink(pdev, drvdata); if (ret) { + smb_config_inport(&pdev->dev, false); dev_err(dev, "Failed to register SMB sink\n"); return ret; } =20 - ret =3D smb_config_inport(dev, true); - if (ret) { - smb_unregister_sink(drvdata); - return ret; - } - - platform_set_drvdata(pdev, drvdata); - return 0; } =20 static int smb_remove(struct platform_device *pdev) { struct smb_drv_data *drvdata =3D platform_get_drvdata(pdev); - int ret; - - ret =3D smb_config_inport(&pdev->dev, false); - if (ret) - return ret; =20 smb_unregister_sink(drvdata); =20 - return 0; + return smb_config_inport(&pdev->dev, false); } =20 #ifdef CONFIG_ACPI --=20 2.33.0 From nobody Tue Dec 16 19:56:40 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B21A6C001E0 for ; Sat, 21 Oct 2023 08:38:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230181AbjJUIiE (ORCPT ); Sat, 21 Oct 2023 04:38:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229600AbjJUIiA (ORCPT ); Sat, 21 Oct 2023 04:38:00 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54A3AD5E for ; Sat, 21 Oct 2023 01:37:57 -0700 (PDT) Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4SCF8L18s6zcd4q; Sat, 21 Oct 2023 16:33:06 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Sat, 21 Oct 2023 16:37:53 +0800 From: Junhao He To: , CC: , , , , , , , Subject: [PATCH v2 3/4] coresight: ultrasoc-smb: Fix uninitialized before use buf_hw_base Date: Sat, 21 Oct 2023 16:38:21 +0800 Message-ID: <20231021083822.18239-4-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231021083822.18239-1-hejunhao3@huawei.com> References: <20231021083822.18239-1-hejunhao3@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In smb_reset_buffer, the sdb->buf_hw_base variable is uninitialized before use, which initializes it in smb_init_data_buffer. And the SMB regiester are set in smb_config_inport. So move the call after smb_config_inport. Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer = driver") Signed-off-by: Junhao He --- drivers/hwtracing/coresight/ultrasoc-smb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing= /coresight/ultrasoc-smb.c index c61450f74cb1..2ee6bf5b725e 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -477,7 +477,6 @@ static int smb_init_data_buffer(struct platform_device = *pdev, static void smb_init_hw(struct smb_drv_data *drvdata) { smb_disable_hw(drvdata); - smb_reset_buffer(drvdata); =20 writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); @@ -587,6 +586,7 @@ static int smb_probe(struct platform_device *pdev) if (ret) return ret; =20 + smb_reset_buffer(drvdata); platform_set_drvdata(pdev, drvdata); spin_lock_init(&drvdata->spinlock); drvdata->pid =3D -1; --=20 2.33.0 From nobody Tue Dec 16 19:56:40 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD237C004C0 for ; Sat, 21 Oct 2023 08:38:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230042AbjJUIiB (ORCPT ); Sat, 21 Oct 2023 04:38:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbjJUIh7 (ORCPT ); Sat, 21 Oct 2023 04:37:59 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27BE4D41 for ; Sat, 21 Oct 2023 01:37:56 -0700 (PDT) Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4SCF9Y3D4HzVlZj; Sat, 21 Oct 2023 16:34:09 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Sat, 21 Oct 2023 16:37:54 +0800 From: Junhao He To: , CC: , , , , , , , Subject: [PATCH v2 4/4] coresight: ultrasoc-smb: Use guards to cleanup Date: Sat, 21 Oct 2023 16:38:22 +0800 Message-ID: <20231021083822.18239-5-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231021083822.18239-1-hejunhao3@huawei.com> References: <20231021083822.18239-1-hejunhao3@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Use guards to reduce gotos and simplify control flow. Signed-off-by: Junhao He --- drivers/hwtracing/coresight/ultrasoc-smb.c | 70 +++++++--------------- 1 file changed, 22 insertions(+), 48 deletions(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing= /coresight/ultrasoc-smb.c index 2ee6bf5b725e..5140782b1b5d 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -97,27 +97,19 @@ static int smb_open(struct inode *inode, struct file *f= ile) { struct smb_drv_data *drvdata =3D container_of(file->private_data, struct smb_drv_data, miscdev); - int ret =3D 0; =20 - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); =20 - if (drvdata->reading) { - ret =3D -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; =20 - if (atomic_read(&drvdata->csdev->refcnt)) { - ret =3D -EBUSY; - goto out; - } + if (atomic_read(&drvdata->csdev->refcnt)) + return -EBUSY; =20 smb_update_data_size(drvdata); - drvdata->reading =3D true; -out: - spin_unlock(&drvdata->spinlock); =20 - return ret; + return 0; } =20 static ssize_t smb_read(struct file *file, char __user *data, size_t len, @@ -160,9 +152,8 @@ static int smb_release(struct inode *inode, struct file= *file) struct smb_drv_data *drvdata =3D container_of(file->private_data, struct smb_drv_data, miscdev); =20 - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); drvdata->reading =3D false; - spin_unlock(&drvdata->spinlock); =20 return 0; } @@ -255,19 +246,15 @@ static int smb_enable(struct coresight_device *csdev,= enum cs_mode mode, struct smb_drv_data *drvdata =3D dev_get_drvdata(csdev->dev.parent); int ret =3D 0; =20 - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); =20 /* Do nothing, the trace data is reading by other interface now */ - if (drvdata->reading) { - ret =3D -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; =20 /* Do nothing, the SMB is already enabled as other mode */ - if (drvdata->mode !=3D CS_MODE_DISABLED && drvdata->mode !=3D mode) { - ret =3D -EBUSY; - goto out; - } + if (drvdata->mode !=3D CS_MODE_DISABLED && drvdata->mode !=3D mode) + return -EBUSY; =20 switch (mode) { case CS_MODE_SYSFS: @@ -281,13 +268,10 @@ static int smb_enable(struct coresight_device *csdev,= enum cs_mode mode, } =20 if (ret) - goto out; + return ret; =20 atomic_inc(&csdev->refcnt); - dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); -out: - spin_unlock(&drvdata->spinlock); =20 return ret; } @@ -295,19 +279,14 @@ static int smb_enable(struct coresight_device *csdev,= enum cs_mode mode, static int smb_disable(struct coresight_device *csdev) { struct smb_drv_data *drvdata =3D dev_get_drvdata(csdev->dev.parent); - int ret =3D 0; =20 - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); =20 - if (drvdata->reading) { - ret =3D -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; =20 - if (atomic_dec_return(&csdev->refcnt)) { - ret =3D -EBUSY; - goto out; - } + if (atomic_dec_return(&csdev->refcnt)) + return -EBUSY; =20 /* Complain if we (somehow) got out of sync */ WARN_ON_ONCE(drvdata->mode =3D=3D CS_MODE_DISABLED); @@ -317,12 +296,9 @@ static int smb_disable(struct coresight_device *csdev) /* Dissociate from the target process. */ drvdata->pid =3D -1; drvdata->mode =3D CS_MODE_DISABLED; - dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); -out: - spin_unlock(&drvdata->spinlock); =20 - return ret; + return 0; } =20 static void *smb_alloc_buffer(struct coresight_device *csdev, @@ -395,17 +371,17 @@ static unsigned long smb_update_buffer(struct coresig= ht_device *csdev, struct smb_drv_data *drvdata =3D dev_get_drvdata(csdev->dev.parent); struct smb_data_buffer *sdb =3D &drvdata->sdb; struct cs_buffers *buf =3D sink_config; - unsigned long data_size =3D 0; + unsigned long data_size; bool lost =3D false; =20 if (!buf) return 0; =20 - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); =20 /* Don't do anything if another tracer is using this sink. */ if (atomic_read(&csdev->refcnt) !=3D 1) - goto out; + return 0; =20 smb_disable_hw(drvdata); smb_update_data_size(drvdata); @@ -424,8 +400,6 @@ static unsigned long smb_update_buffer(struct coresight= _device *csdev, smb_sync_perf_buffer(drvdata, buf, handle->head); if (!buf->snapshot && lost) perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); -out: - spin_unlock(&drvdata->spinlock); =20 return data_size; } --=20 2.33.0