Re: [Patch V2] xen: use correct type for HYPERVISOR_memory_op()

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 09/14/2015 09:13 AM, Juergen Gross wrote:
> HYPERVISOR_memory_op() is defined to return an "int" value. This is
> wrong, as the Xen hypervisor will return "long".
>
> The sub-function XENMEM_maximum_reservation returns the maximum
> number of pages for the current domain. An int will overflow for a
> domain configured with 8TB of memory or more.
>
> Correct this by using the correct type.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>


>
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> V2: change arm header as well to keep it in sync with x86
>      (requested by Julien Grall)
> ---
>   arch/arm/include/asm/xen/hypercall.h | 2 +-
>   arch/x86/include/asm/xen/hypercall.h | 4 ++--
>   arch/x86/xen/setup.c                 | 2 +-
>   3 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h
> index 712b50e..47f0d81 100644
> --- a/arch/arm/include/asm/xen/hypercall.h
> +++ b/arch/arm/include/asm/xen/hypercall.h
> @@ -45,7 +45,7 @@ int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
>   int HYPERVISOR_sched_op(int cmd, void *arg);
>   int HYPERVISOR_event_channel_op(int cmd, void *arg);
>   unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> -int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> +long HYPERVISOR_memory_op(unsigned int cmd, void *arg);
>   int HYPERVISOR_physdev_op(int cmd, void *arg);
>   int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
>   int HYPERVISOR_tmem_op(void *arg);
> diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
> index 83aea80..4c20dd3 100644
> --- a/arch/x86/include/asm/xen/hypercall.h
> +++ b/arch/x86/include/asm/xen/hypercall.h
> @@ -336,10 +336,10 @@ HYPERVISOR_update_descriptor(u64 ma, u64 desc)
>   	return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
>   }
>   
> -static inline int
> +static inline long
>   HYPERVISOR_memory_op(unsigned int cmd, void *arg)
>   {
> -	return _hypercall2(int, memory_op, cmd, arg);
> +	return _hypercall2(long, memory_op, cmd, arg);
>   }
>   
>   static inline int
> diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
> index f5ef674..4ebfcec 100644
> --- a/arch/x86/xen/setup.c
> +++ b/arch/x86/xen/setup.c
> @@ -548,7 +548,7 @@ static unsigned long __init xen_get_max_pages(void)
>   {
>   	unsigned long max_pages, limit;
>   	domid_t domid = DOMID_SELF;
> -	int ret;
> +	long ret;
>   
>   	limit = xen_get_pages_limit();
>   	max_pages = limit;