* [PATCH] xen/xenbus: Don't leak memory when unmapping the ring on HVM backend
@ 2015-08-10 18:10 Julien Grall
0 siblings, 0 replies; 4+ messages in thread
From: Julien Grall @ 2015-08-10 18:10 UTC (permalink / raw)
To: xen-devel
Cc: Wei Liu, linux-kernel, Julien Grall, David Vrabel, Boris Ostrovsky
The commit ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d "xenbus_client:
Extend interface to support multi-page ring" removes the call to
free_xenballooned_pages in xenbus_unmap_ring_vfree_hvm.
This will result to not give back the pages to Linux and loose them
forever. It only happens when the backends are running in HVM domains.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
---
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Appeared in Linux 4.1. HVM backend, which is always the case on ARM, will
leak every mapped ring (i.e ~12KB per domain with 1 disk and 1 vif).
---
drivers/xen/xenbus/xenbus_client.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 9ad3272..e303535 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -814,8 +814,10 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
addrs);
- if (!rv)
+ if (!rv) {
vunmap(vaddr);
+ free_xenballooned_pages(node->nr_handles, node->hvm.pages);
+ }
else
WARN(1, "Leaking %p, size %u page(s)\n", vaddr,
node->nr_handles);
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] xen/xenbus: Don't leak memory when unmapping the ring on HVM backend
[not found] <1439230238-6413-1-git-send-email-julien.grall@citrix.com>
2015-08-10 18:38 ` Boris Ostrovsky
2015-08-10 18:46 ` Wei Liu
@ 2015-08-11 10:05 ` David Vrabel
2 siblings, 0 replies; 4+ messages in thread
From: David Vrabel @ 2015-08-11 10:05 UTC (permalink / raw)
To: Julien Grall, xen-devel
Cc: Boris Ostrovsky, Wei Liu, linux-kernel, David Vrabel
On 10/08/15 19:10, Julien Grall wrote:
> The commit ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d "xenbus_client:
> Extend interface to support multi-page ring" removes the call to
> free_xenballooned_pages in xenbus_unmap_ring_vfree_hvm.
>
> This will result to not give back the pages to Linux and loose them
> forever. It only happens when the backends are running in HVM domains.
Applied to for-linus-4.2 and tagged for stable, thanks.
David
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] xen/xenbus: Don't leak memory when unmapping the ring on HVM backend
[not found] <1439230238-6413-1-git-send-email-julien.grall@citrix.com>
2015-08-10 18:38 ` Boris Ostrovsky
@ 2015-08-10 18:46 ` Wei Liu
2015-08-11 10:05 ` David Vrabel
2 siblings, 0 replies; 4+ messages in thread
From: Wei Liu @ 2015-08-10 18:46 UTC (permalink / raw)
To: Julien Grall
Cc: Wei Liu, linux-kernel, David Vrabel, xen-devel, Boris Ostrovsky
On Mon, Aug 10, 2015 at 07:10:38PM +0100, Julien Grall wrote:
> The commit ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d "xenbus_client:
> Extend interface to support multi-page ring" removes the call to
> free_xenballooned_pages in xenbus_unmap_ring_vfree_hvm.
>
> This will result to not give back the pages to Linux and loose them
> forever. It only happens when the backends are running in HVM domains.
>
> Signed-off-by: Julien Grall <julien.grall@citrix.com>
>
> ---
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: David Vrabel <david.vrabel@citrix.com>
> Cc: Wei Liu <wei.liu2@citrix.com>
>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
> Appeared in Linux 4.1. HVM backend, which is always the case on ARM, will
> leak every mapped ring (i.e ~12KB per domain with 1 disk and 1 vif).
> ---
> drivers/xen/xenbus/xenbus_client.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
> index 9ad3272..e303535 100644
> --- a/drivers/xen/xenbus/xenbus_client.c
> +++ b/drivers/xen/xenbus/xenbus_client.c
> @@ -814,8 +814,10 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
>
> rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
> addrs);
> - if (!rv)
> + if (!rv) {
> vunmap(vaddr);
> + free_xenballooned_pages(node->nr_handles, node->hvm.pages);
> + }
> else
> WARN(1, "Leaking %p, size %u page(s)\n", vaddr,
> node->nr_handles);
> --
> 2.1.4
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] xen/xenbus: Don't leak memory when unmapping the ring on HVM backend
[not found] <1439230238-6413-1-git-send-email-julien.grall@citrix.com>
@ 2015-08-10 18:38 ` Boris Ostrovsky
2015-08-10 18:46 ` Wei Liu
2015-08-11 10:05 ` David Vrabel
2 siblings, 0 replies; 4+ messages in thread
From: Boris Ostrovsky @ 2015-08-10 18:38 UTC (permalink / raw)
To: Julien Grall, xen-devel; +Cc: David Vrabel, Wei Liu, linux-kernel
On 08/10/2015 02:10 PM, Julien Grall wrote:
> The commit ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d "xenbus_client:
> Extend interface to support multi-page ring" removes the call to
> free_xenballooned_pages in xenbus_unmap_ring_vfree_hvm.
>
> This will result to not give back the pages to Linux and loose them
> forever. It only happens when the backends are running in HVM domains.
>
> Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>
> ---
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: David Vrabel <david.vrabel@citrix.com>
> Cc: Wei Liu <wei.liu2@citrix.com>
>
> Appeared in Linux 4.1. HVM backend, which is always the case on ARM, will
> leak every mapped ring (i.e ~12KB per domain with 1 disk and 1 vif).
> ---
> drivers/xen/xenbus/xenbus_client.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
> index 9ad3272..e303535 100644
> --- a/drivers/xen/xenbus/xenbus_client.c
> +++ b/drivers/xen/xenbus/xenbus_client.c
> @@ -814,8 +814,10 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
>
> rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
> addrs);
> - if (!rv)
> + if (!rv) {
> vunmap(vaddr);
> + free_xenballooned_pages(node->nr_handles, node->hvm.pages);
> + }
> else
> WARN(1, "Leaking %p, size %u page(s)\n", vaddr,
> node->nr_handles);
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-08-11 10:05 UTC | newest]
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2015-08-10 18:10 [PATCH] xen/xenbus: Don't leak memory when unmapping the ring on HVM backend Julien Grall
[not found] <1439230238-6413-1-git-send-email-julien.grall@citrix.com>
2015-08-10 18:38 ` Boris Ostrovsky
2015-08-10 18:46 ` Wei Liu
2015-08-11 10:05 ` David Vrabel
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