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* [PATCH] vhost-vdpa: Refactor copy_to_user() usage in vhost_vdpa_get_config()
@ 2024-09-25 18:48 Markus Elfring
  2024-09-25 20:50 ` Al Viro
  0 siblings, 1 reply; 3+ messages in thread
From: Markus Elfring @ 2024-09-25 18:48 UTC (permalink / raw)
  To: virtualization, kvm, netdev, Eugenio Pérez, Jason Wang,
	Michael S. Tsirkin, Tiwei Bie
  Cc: LKML, kernel-janitors

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 25 Sep 2024 20:36:35 +0200

Assign the return value from a copy_to_user() call to an additional
local variable so that a kvfree() call and return statement can be
omitted accordingly.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/vhost/vdpa.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 5a49b5a6d496..ca69527a822c 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -370,13 +370,11 @@ static long vhost_vdpa_get_config(struct vhost_vdpa *v,

 	vdpa_get_config(vdpa, config.off, buf, config.len);

-	if (copy_to_user(c->buf, buf, config.len)) {
+	{
+		unsigned long ctu = copy_to_user(c->buf, buf, config.len);
 		kvfree(buf);
-		return -EFAULT;
+		return ctu ? -EFAULT : 0;
 	}
-
-	kvfree(buf);
-	return 0;
 }

 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
--
2.46.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] vhost-vdpa: Refactor copy_to_user() usage in vhost_vdpa_get_config()
  2024-09-25 18:48 [PATCH] vhost-vdpa: Refactor copy_to_user() usage in vhost_vdpa_get_config() Markus Elfring
@ 2024-09-25 20:50 ` Al Viro
  2024-09-26  6:04   ` Markus Elfring
  0 siblings, 1 reply; 3+ messages in thread
From: Al Viro @ 2024-09-25 20:50 UTC (permalink / raw)
  To: Markus Elfring
  Cc: virtualization, kvm, netdev, Eugenio Pérez, Jason Wang,
	Michael S. Tsirkin, Tiwei Bie, LKML, kernel-janitors

On Wed, Sep 25, 2024 at 08:48:16PM +0200, Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 25 Sep 2024 20:36:35 +0200
> 
> Assign the return value from a copy_to_user() call to an additional
> local variable so that a kvfree() call and return statement can be
> omitted accordingly.

Ugly and unidiomatic.

> This issue was detected by using the Coccinelle software.

What issue?

> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Nevermind (and I really need more coffee, seeing that I'd missed the
obvious indicator of garbage and failed to hit delete)...

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: vhost-vdpa: Refactor copy_to_user() usage in vhost_vdpa_get_config()
  2024-09-25 20:50 ` Al Viro
@ 2024-09-26  6:04   ` Markus Elfring
  0 siblings, 0 replies; 3+ messages in thread
From: Markus Elfring @ 2024-09-26  6:04 UTC (permalink / raw)
  To: Al Viro, virtualization, kvm, netdev, Eugenio Pérez,
	Jason Wang, Michael S. Tsirkin
  Cc: LKML, kernel-janitors

>> Assign the return value from a copy_to_user() call to an additional
>> local variable so that a kvfree() call and return statement can be
>> omitted accordingly.
>
> Ugly and unidiomatic.
>
>> This issue was detected by using the Coccinelle software.
>
> What issue?

Opportunities for the reduction of duplicate source code.

Regards,
Markus

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2024-09-26  6:04 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2024-09-25 18:48 [PATCH] vhost-vdpa: Refactor copy_to_user() usage in vhost_vdpa_get_config() Markus Elfring
2024-09-25 20:50 ` Al Viro
2024-09-26  6:04   ` Markus Elfring

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