2014-06-02 17:51:59

by Fabian Frédérick

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

This patch also removes unnecessary printk(KERN_INFO

Cc: Anil Gurumurthy <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: One Thousand Gnomes <[email protected]>
Cc: Joe Perches <[email protected]>
Signed-off-by: Fabian Frederick <[email protected]>
---

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

2014-06-02 17:56:56

by Joe Perches

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

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.