From patchwork Sat Oct 21 08:38:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junhao He X-Patchwork-Id: 13431440 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 DBD67C0032E for ; Sat, 21 Oct 2023 08:38:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=spdXtoe2zjc4jluJ+Qsx4YQpZMdstAmqIn0QXCPDMho=; b=TVb3oShN/EDM6N 9x2HO740hcrlc6w+zKwP5BlG17bzxz0qNjlEK7vYVlLLWPhr4/xC+VsfNlDEgMPtuDN1bO2u4eSUz nxvvB5TXrjhBN/J8u+NArTp7TMppMOTulZsTGWMa8nfzdIxVDryW/1Efam+LXcXlN1rRCISvaXs3/ wC294Zz79J02R+6tYMD6GkOY2NDReihspUsvPcniz8yMi6KXAs9gG5oq46JKmRSveMnQ8tiNI/49p S7ydZDkwXF+XAIJt/BCiDcC0fbjib9dDW95xHgawhqlO8uRGBTUbQZPRrjnuKVLv5L5r/oKgC+hNM dLVue0VlcCUlxHcodv/g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qu7Ul-003ew0-15; Sat, 21 Oct 2023 08:38:07 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qu7Ug-003euJ-2d for linux-arm-kernel@lists.infradead.org; Sat, 21 Oct 2023 08:38:05 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231021_013803_332657_DFDDFFCC X-CRM114-Status: GOOD ( 19.52 ) 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 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+0xae8/0x2b48 softirqs last enabled at (0): [] copy_process+0xae8/0x2b48 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 *file) struct smb_drv_data, miscdev); int ret = 0; - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); if (drvdata->reading) { ret = -EBUSY; @@ -115,7 +115,7 @@ static int smb_open(struct inode *inode, struct file *file) drvdata->reading = true; out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); return ret; } @@ -132,10 +132,8 @@ static ssize_t smb_read(struct file *file, char __user *data, size_t len, if (!len) return 0; - mutex_lock(&drvdata->mutex); - if (!sdb->data_size) - goto out; + return 0; to_copy = min(sdb->data_size, len); @@ -145,20 +143,15 @@ static ssize_t smb_read(struct file *file, char __user *data, size_t len, 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 = -EFAULT; - goto out; + return -EFAULT; } *ppos += 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); + dev_dbg(dev, "%zu bytes copied\n", to_copy); return to_copy; } @@ -167,9 +160,9 @@ static int smb_release(struct inode *inode, struct file *file) struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); drvdata->reading = false; - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); return 0; } @@ -262,7 +255,7 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); int ret = 0; - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); /* 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, enum cs_mode mode, dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); return ret; } @@ -304,7 +297,7 @@ static int smb_disable(struct coresight_device *csdev) struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); int ret = 0; - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); if (drvdata->reading) { ret = -EBUSY; @@ -327,7 +320,7 @@ static int smb_disable(struct coresight_device *csdev) dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); out: - mutex_unlock(&drvdata->mutex); + spin_unlock(&drvdata->spinlock); return ret; } @@ -408,7 +401,7 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev, if (!buf) return 0; - mutex_lock(&drvdata->mutex); + spin_lock(&drvdata->spinlock); /* Don't do anything if another tracer is using this sink. */ if (atomic_read(&csdev->refcnt) != 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); return data_size; } @@ -590,7 +583,7 @@ static int smb_probe(struct platform_device *pdev) return ret; } - mutex_init(&drvdata->mutex); + spin_lock_init(&drvdata->spinlock); drvdata->pid = -1; ret = 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 #include -#include +#include /* 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; From patchwork Sat Oct 21 08:38:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junhao He X-Patchwork-Id: 13431441 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 6556BC004C0 for ; Sat, 21 Oct 2023 08:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231021_013804_788400_AC9E92C0 X-CRM114-Status: GOOD ( 10.30 ) 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 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; } + ret = smb_config_inport(dev, true); + if (ret) + return ret; + + platform_set_drvdata(pdev, drvdata); spin_lock_init(&drvdata->spinlock); drvdata->pid = -1; ret = smb_register_sink(pdev, drvdata); if (ret) { + smb_config_inport(&pdev->dev, false); dev_err(dev, "Failed to register SMB sink\n"); return ret; } - ret = smb_config_inport(dev, true); - if (ret) { - smb_unregister_sink(drvdata); - return ret; - } - - platform_set_drvdata(pdev, drvdata); - return 0; } static int smb_remove(struct platform_device *pdev) { struct smb_drv_data *drvdata = platform_get_drvdata(pdev); - int ret; - - ret = smb_config_inport(&pdev->dev, false); - if (ret) - return ret; smb_unregister_sink(drvdata); - return 0; + return smb_config_inport(&pdev->dev, false); } #ifdef CONFIG_ACPI From patchwork Sat Oct 21 08:38:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junhao He X-Patchwork-Id: 13431442 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 7C981C0032E for ; Sat, 21 Oct 2023 08:38:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ypEFMYDOkcCktQgQe5+Z8gKa8B2xPU8eOgDlSR6E/m0=; b=agtAhvYII2/dad FhblQ5EgxLNySLysrX3ieMshqTgOWKTK5YvreUnsZiBqdPwFRZgVipdZcr7+o7hTT5nk7ssP2GOAN dIHO/ET85UCxZ0auhbbOS1rUGssbLma4yj2mbmhvd0Yj9VLhzlru/1Z4gAH1ookOXwLtOHOkMPOKl vumwNEBvno8g6v7ticLf+wfpjqcDwCsCupT/ZvsNsFxr6s9uGhWyHPNJSGzQBfxxHitGxAmLkif3y gxe6ZTd56whEnjECO75gE0evo5qkQPMcp9qoYXYx8hcoGFRr0uXKN9WVaz3h0k8dqKIAHpanZ3nZC RwBgWNdmX3CBgWrQtjmQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qu7Uy-003exv-0b; Sat, 21 Oct 2023 08:38:20 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qu7Uh-003euB-0S for linux-arm-kernel@lists.infradead.org; Sat, 21 Oct 2023 08:38:06 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231021_013803_404902_27A3CE53 X-CRM114-Status: GOOD ( 11.39 ) 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 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); 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; + smb_reset_buffer(drvdata); platform_set_drvdata(pdev, drvdata); spin_lock_init(&drvdata->spinlock); drvdata->pid = -1; From patchwork Sat Oct 21 08:38:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junhao He X-Patchwork-Id: 13431439 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 5F694C001E0 for ; Sat, 21 Oct 2023 08:38:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=noKWk/yAROKOSAujCpJLX8eEaGMrBkPOJNz5eXBZH7Y=; b=qAjszaze8QQ7QA uCBki6kxO1jvie1UYkTJP5thEwq5xCYR0gXlnn1Hv5keuhGtWEO6no+bPvZcbh9CCIksDmAWtsmKm 5mpAsHLfvYF36M0ovR9GhwWmxpknIKV+lgQs/RWnOSaZ6A+/cXgbmGx7P4INdsPraza5td1BD4or+ IfeMoo198btEv4SA7jkLK8h8QKw3MkAJAiscQpsnfUsP1Rs1PCnACz7wfi3BG8XOmnclm4c9V+GMT ktYDLC/sXwgw68zXw6DUgyzbmV50eXOgvfH5HCXYStbpRRr+/C70cLMDQOEwNbzI/ucrMUQg8vGr0 nsky6BJ4hwveJsXpC7aQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qu7Uk-003evh-2L; Sat, 21 Oct 2023 08:38:06 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qu7Ug-003euA-2d for linux-arm-kernel@lists.infradead.org; Sat, 21 Oct 2023 08:38:05 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231021_013803_332418_48289969 X-CRM114-Status: GOOD ( 15.10 ) 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 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 *file) { struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); - int ret = 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); - if (drvdata->reading) { - ret = -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; - if (atomic_read(&drvdata->csdev->refcnt)) { - ret = -EBUSY; - goto out; - } + if (atomic_read(&drvdata->csdev->refcnt)) + return -EBUSY; smb_update_data_size(drvdata); - drvdata->reading = true; -out: - spin_unlock(&drvdata->spinlock); - return ret; + return 0; } 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 = container_of(file->private_data, struct smb_drv_data, miscdev); - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); drvdata->reading = false; - spin_unlock(&drvdata->spinlock); return 0; } @@ -255,19 +246,15 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); int ret = 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); /* Do nothing, the trace data is reading by other interface now */ - if (drvdata->reading) { - ret = -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; /* Do nothing, the SMB is already enabled as other mode */ - if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) { - ret = -EBUSY; - goto out; - } + if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) + return -EBUSY; switch (mode) { case CS_MODE_SYSFS: @@ -281,13 +268,10 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, } if (ret) - goto out; + return ret; atomic_inc(&csdev->refcnt); - dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); -out: - spin_unlock(&drvdata->spinlock); 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 = dev_get_drvdata(csdev->dev.parent); - int ret = 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); - if (drvdata->reading) { - ret = -EBUSY; - goto out; - } + if (drvdata->reading) + return -EBUSY; - if (atomic_dec_return(&csdev->refcnt)) { - ret = -EBUSY; - goto out; - } + if (atomic_dec_return(&csdev->refcnt)) + return -EBUSY; /* Complain if we (somehow) got out of sync */ WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); @@ -317,12 +296,9 @@ static int smb_disable(struct coresight_device *csdev) /* Dissociate from the target process. */ drvdata->pid = -1; drvdata->mode = CS_MODE_DISABLED; - dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); -out: - spin_unlock(&drvdata->spinlock); - return ret; + return 0; } static void *smb_alloc_buffer(struct coresight_device *csdev, @@ -395,17 +371,17 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev, struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); struct smb_data_buffer *sdb = &drvdata->sdb; struct cs_buffers *buf = sink_config; - unsigned long data_size = 0; + unsigned long data_size; bool lost = false; if (!buf) return 0; - spin_lock(&drvdata->spinlock); + guard(spinlock)(&drvdata->spinlock); /* Don't do anything if another tracer is using this sink. */ if (atomic_read(&csdev->refcnt) != 1) - goto out; + return 0; 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); return data_size; }