From: Junhao He <hejunhao3@huawei.com>
To: <suzuki.poulose@arm.com>, <james.clark@arm.com>
Cc: <coresight@lists.linaro.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <linuxarm@huawei.com>,
<jonathan.cameron@huawei.com>, <yangyicong@huawei.com>,
<prime.zeng@hisilicon.com>, <hejunhao3@huawei.com>
Subject: [PATCH 2/3] coresight: ultrasoc-smb: simplify the code for check to_copy valid
Date: Thu, 12 Oct 2023 17:47:05 +0800 [thread overview]
Message-ID: <20231012094706.21565-3-hejunhao3@huawei.com> (raw)
In-Reply-To: <20231012094706.21565-1-hejunhao3@huawei.com>
We only need to check once when before using the to_copy variable
to simplify the code.
Signed-off-by: Junhao He <hejunhao3@huawei.com>
---
drivers/hwtracing/coresight/ultrasoc-smb.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index b08a619d1116..e78edc3480ce 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -127,20 +127,15 @@ static ssize_t smb_read(struct file *file, char __user *data, size_t len,
struct smb_drv_data, miscdev);
struct smb_data_buffer *sdb = &drvdata->sdb;
struct device *dev = &drvdata->csdev->dev;
- ssize_t to_copy = 0;
-
- if (!len)
- return 0;
-
- if (!sdb->data_size)
- return 0;
-
- to_copy = min(sdb->data_size, len);
+ ssize_t to_copy = min(sdb->data_size, len);
/* Copy parts of trace data when read pointer wrap around SMB buffer */
if (sdb->buf_rdptr + to_copy > sdb->buf_size)
to_copy = sdb->buf_size - sdb->buf_rdptr;
+ if (!to_copy)
+ return 0;
+
if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) {
dev_dbg(dev, "Failed to copy data to user\n");
return -EFAULT;
--
2.33.0
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next prev parent reply other threads:[~2023-10-12 9:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-12 9:47 [PATCH 0/3] Fixed some issues and cleanup of ultrasoc-smb Junhao He
2023-10-12 9:47 ` [PATCH 1/3] coresight: ultrasoc-smb: fix sleep while close preempt in enable_smb Junhao He
2023-10-19 3:05 ` Yicong Yang
2023-10-19 12:45 ` hejunhao
2023-10-19 13:30 ` Jonathan Cameron
2023-10-21 7:25 ` hejunhao
2023-10-12 9:47 ` Junhao He [this message]
2023-10-19 13:35 ` [PATCH 2/3] coresight: ultrasoc-smb: simplify the code for check to_copy valid Jonathan Cameron
2023-10-20 2:33 ` hejunhao
2023-10-12 9:47 ` [PATCH 3/3] coresight: ultrasoc-smb: fix uninitialized before use buf_hw_base Junhao He
2023-10-19 2:34 ` Yicong Yang
2023-10-19 13:08 ` hejunhao
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