[PATCH] tracing: Don't use the address of the buffer array name in copy_from_user

[Wang Xiaoqiang <wangxq10@lzu.edu.cn>]

Hi, all,

>From 7dbacb179a4d5f9ac9d7e1b3733664b3b0fe23ae Mon Sep 17 00:00:00 2001
From: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Date: Mon, 18 Apr 2016 14:58:15 +0800
Subject: [PATCH] tracing: Don't use the address of the buffer array name in
 copy_from_user

Fix the problem as follows:

    ...
    char buf[64];
    ...
    if (copy_from_user(&buf, ubuf, cnt))
    ...

Even though the value of "&buf" equals "buf", but there is no need
to get the address of the "buf" again. Use "buf" replace "&buf".

Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
---
 kernel/trace/trace.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a2f0b9f..422ab57 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3658,7 +3658,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 	if (cnt >= sizeof(buf))
 		return -EINVAL;
 
-	if (copy_from_user(&buf, ubuf, cnt))
+	if (copy_from_user(buf, ubuf, cnt))
 		return -EFAULT;
 
 	buf[cnt] = 0;
@@ -4474,7 +4474,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 	if (cnt > MAX_TRACER_SIZE)
 		cnt = MAX_TRACER_SIZE;
 
-	if (copy_from_user(&buf, ubuf, cnt))
+	if (copy_from_user(buf, ubuf, cnt))
 		return -EFAULT;
 
 	buf[cnt] = 0;
@@ -5264,7 +5264,7 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
 	if (cnt >= sizeof(buf))
 		return -EINVAL;
 
-	if (copy_from_user(&buf, ubuf, cnt))
+	if (copy_from_user(buf, ubuf, cnt))
 		return -EFAULT;
 
 	buf[cnt] = 0;
-- 
2.1.4