From: David Vrabel <david.vrabel@citrix.com>
To: Ross Lagerwall <ross.lagerwall@citrix.com>,
xen-devel@lists.xenproject.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
David Vrabel <david.vrabel@citrix.com>
Subject: Re: [PATCH 2/2] xen/balloon: Fix crash when ballooning on x86 32 bit PAE
Date: Wed, 6 Apr 2016 13:48:17 +0100 [thread overview]
Message-ID: <57050591.6040609@citrix.com> (raw)
In-Reply-To: <1458233520-18821-2-git-send-email-ross.lagerwall@citrix.com>
These two have been applied to for-linus-4.6, thanks.
I tagged them for stable since they are regression in 4.4.
On 17/03/16 16:52, Ross Lagerwall wrote:
> When ballooning on an x86 32 bit PAE system with close to 64 GiB of memory, the
> address returned by allocate_resource may be above 64 GiB. When using
> CONFIG_SPARSEMEM, this setup is limited to using physical addresses < 64 GiB.
> When adding memory at this address, it runs off the end of the mem_section
> array and causes a crash. Instead, fail the ballooning request.
>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
> ---
> drivers/xen/balloon.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 12eab50..329695d 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -152,6 +152,8 @@ static DECLARE_WAIT_QUEUE_HEAD(balloon_wq);
> static void balloon_process(struct work_struct *work);
> static DECLARE_DELAYED_WORK(balloon_worker, balloon_process);
>
> +static void release_memory_resource(struct resource *resource);
> +
> /* When ballooning out (allocating memory to return to Xen) we don't really
> want the kernel to try too hard since that can trigger the oom killer. */
> #define GFP_BALLOON \
> @@ -268,6 +270,19 @@ static struct resource *additional_memory_resource(phys_addr_t size)
> return NULL;
> }
>
> +#ifdef CONFIG_SPARSEMEM
> + {
> + unsigned long max_pfn = 1UL << (MAX_PHYSMEM_BITS - PAGE_SHIFT);
I changed max_pfn to limit, to avoid confusion with the global max_pfn.
David
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prev parent reply other threads:[~2016-04-06 12:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-17 16:51 [PATCH 1/2] xen: Fix page <-> pfn conversion on 32 bit systems Ross Lagerwall
2016-03-17 16:52 ` [PATCH 2/2] xen/balloon: Fix crash when ballooning on x86 32 bit PAE Ross Lagerwall
2016-04-06 12:48 ` David Vrabel [this message]
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