Re: [Xen-devel] [PATCH] xen: use correct type for HYPERVISOR_memory_op()

From: Julien Grall
Date: Mon Sep 14 2015 - 08:58:13 EST


Hi Juergen,

On 04/09/15 13:50, 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.

Can you also fix the ARM version of the prototype
(arm/include/asm/xen/hypercall.h) in order to keep them in sync?

Regards,

> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> arch/x86/include/asm/xen/hypercall.h | 4 ++--
> arch/x86/xen/setup.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
> index ca08a27..b7a735f 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;
>


--
Julien Grall
--
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