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Re: [PATCH][VIRTIO] Fix vring_init() ring computations

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[view original message]
From: Anthony Liguori <aliguori@...>
To: <linux-kernel@...>
Cc: Anthony Liguori <aliguori@...>, Rusty Russell <rusty@...>, <virtualization@...>
Subject: [PATCH][VIRTIO] Fix vring_init() ring computations
Date: Tuesday, November 6, 2007 - 10:52 pm

This patch fixes a typo in vring_init().  This happens to work today in lguest

because the sizeof(struct vring_desc) is 16 and struct vring contains 3

pointers and an unsigned int so on 32-bit

sizeof(struct vring_desc) == sizeof(struct vring).  However, this is no longer

true on 64-bit where the bug is exposed.


Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h

index ac69e7b..5b88d21 100644

--- a/include/linux/virtio_ring.h

+++ b/include/linux/virtio_ring.h

@@ -92,8 +92,8 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p)

 {

 	vr->num = num;

 	vr->desc = p;

-	vr->avail = p + num*sizeof(struct vring);

-	vr->used = p + (num+1)*(sizeof(struct vring) + sizeof(__u16));

+	vr->avail = p + num*sizeof(struct vring_desc);

+	vr->used = p + (num+1)*(sizeof(struct vring_desc) + sizeof(__u16));

 }


 static inline unsigned vring_size(unsigned int num)

-
[view original message]
From: Rusty Russell <rusty@...>
To: <virtualization@...>
Cc: Anthony Liguori <aliguori@...>, <linux-kernel@...>, Rusty Russell <rusty@...>, <virtualization@...>
Subject: Re: [PATCH][VIRTIO] Fix vring_init() ring computations
Date: Wednesday, November 7, 2007 - 1:57 am

Thanks, applied.


I've put it in the new, experimental virtio git tree on git.kernel.org.


Cheers,

Rusty.

-
[view original message]
From: Anthony Liguori <aliguori@...>
To: Rusty Russell <rusty@...>
Cc: <virtualization@...>, <linux-kernel@...>, Rusty Russell <rusty@...>, <virtualization@...>
Subject: Re: [PATCH][VIRTIO] Fix vring_init() ring computations
Date: Wednesday, November 7, 2007 - 9:06 pm

Hrm, perhaps you forgot to push?  I don't see it in the tree although I

see the config ops refactoring.


Regards,


-
[view original message]
From: Rusty Russell <rusty@...>
To: Anthony Liguori <aliguori@...>
Cc: <virtualization@...>, <linux-kernel@...>, Rusty Russell <rusty@...>, <virtualization@...>
Subject: Re: [PATCH][VIRTIO] Fix vring_init() ring computations
Date: Wednesday, November 7, 2007 - 10:25 pm

It should be in the patches/1 branch.  I've pushed again...


Thanks,

Rusty.

-
Previous thread: [GIT PULL] FireWire update by Stefan Richter on Tuesday, November 6, 2007 - 9:20 pm. (1 message)

Next thread: Re: [PATCH] SCSI: Add the SGPIO support for sata_nv.c by Yinghai Lu on Wednesday, November 7, 2007 - 12:09 am. (1 message)