[PATCH V3] drivers/scsi/bfa/bfad_debugfs.c: replace 2 kzalloc/copy_from_user by memdup_user

[PATCH V3] drivers/scsi/bfa/bfad_debugfs.c: replace 2 kzalloc/copy_from_user by memdup_user

[Fabian Frederick]

This patch also removes unnecessary printk(KERN_INFO

Cc: Anil Gurumurthy <anil.gurumurthy@qlogic.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
---

V3: memdup_user first argument is already void __user * (thanks to Joe Perches)
    typo in title
V2: Remove printk(KERN_INFO (suggested by Alan)

 drivers/scsi/bfa/bfad_debugfs.c | 28 ++++++----------------------
 1 file changed, 6 insertions(+), 22 deletions(-)

diff --git a/drivers/scsi/bfa/bfad_debugfs.c b/drivers/scsi/bfa/bfad_debugfs.c
index 8e83d04..23e6426 100644
--- a/drivers/scsi/bfa/bfad_debugfs.c
+++ b/drivers/scsi/bfa/bfad_debugfs.c
@@ -260,18 +260,10 @@ bfad_debugfs_write_regrd(struct file *file, const char __user *buf,
 	unsigned long flags;
 	void *kern_buf;
 
-	kern_buf = kzalloc(nbytes, GFP_KERNEL);
+	kern_buf = memdup_user(buf, nbytes);
 
-	if (!kern_buf) {
-		printk(KERN_INFO "bfad[%d]: Failed to allocate buffer\n",
-				bfad->inst_no);
-		return -ENOMEM;
-	}
-
-	if (copy_from_user(kern_buf, (void  __user *)buf, nbytes)) {
-		kfree(kern_buf);
-		return -ENOMEM;
-	}
+	if (IS_ERR(kern_buf))
+		return PTR_ERR(kern_buf);
 
 	rc = sscanf(kern_buf, "%x:%x", &addr, &len);
 	if (rc < 2) {
@@ -336,18 +328,10 @@ bfad_debugfs_write_regwr(struct file *file, const char __user *buf,
 	unsigned long flags;
 	void *kern_buf;
 
-	kern_buf = kzalloc(nbytes, GFP_KERNEL);
+	kern_buf = memdup_user(buf, nbytes);
 
-	if (!kern_buf) {
-		printk(KERN_INFO "bfad[%d]: Failed to allocate buffer\n",
-				bfad->inst_no);
-		return -ENOMEM;
-	}
-
-	if (copy_from_user(kern_buf, (void  __user *)buf, nbytes)) {
-		kfree(kern_buf);
-		return -ENOMEM;
-	}
+	if (IS_ERR(kern_buf))
+		return PTR_ERR(kern_buf);
 
 	rc = sscanf(kern_buf, "%x:%x", &addr, &val);
 	if (rc < 2) {
-- 
1.8.4.5

Re: [PATCH V3] drivers/scsi/bfa/bfad_debugfs.c: replace 2 kzalloc/copy_from_user by memdup_user

[Joe Perches]

On Mon, 2014-06-02 at 19:50 +0200, Fabian Frederick wrote:
> This patch also removes unnecessary printk(KERN_INFO
[]
> diff --git a/drivers/scsi/bfa/bfad_debugfs.c b/drivers/scsi/bfa/bfad_debugfs.c
[]
> @@ -260,18 +260,10 @@ bfad_debugfs_write_regrd(struct file *file, const char __user *buf,
>  	unsigned long flags;
>  	void *kern_buf;
>  
> -	kern_buf = kzalloc(nbytes, GFP_KERNEL);
> +	kern_buf = memdup_user(buf, nbytes);
>  

trivial note:

There's an uncommon blank line here.

Generally this form is:

	foo = memdup_user(bar, len);
	if (IS_ERR(foo))

not

	foo = memdup_user(bar, len);

	if (IS_ERR(foo))


> @@ -336,18 +328,10 @@ bfad_debugfs_write_regwr(struct file *file, const char __user *buf,
>  	unsigned long flags;
>  	void *kern_buf;
>  
> -	kern_buf = kzalloc(nbytes, GFP_KERNEL);
> +	kern_buf = memdup_user(buf, nbytes);
>  

here too.