diff mbox

xen/arm: add_to_physmap_one: Avoid to map mfn 0 if an error occurs

Message ID 1382545727-6595-1-git-send-email-julien.grall@linaro.org
State Accepted, archived
Headers show

Commit Message

Julien Grall Oct. 23, 2013, 4:28 p.m. UTC
By default, the function add_to_physmap_one set mfn to 0. Some code paths that
result to an error, continue and the map the mfn 0 (valid on ARM) to the
slot given by the guest.

To fix the problem, return directly an error if sanity check has failed.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
---
 xen/arch/arm/mm.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Tim Deegan Oct. 24, 2013, 8:11 a.m. UTC | #1
At 17:28 +0100 on 23 Oct (1382545727), Julien Grall wrote:
> By default, the function add_to_physmap_one set mfn to 0. Some code paths that
> result to an error, continue and the map the mfn 0 (valid on ARM) to the
> slot given by the guest.
> 
> To fix the problem, return directly an error if sanity check has failed.
> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>

Acked-by: Tim Deegan <tim@xen.org>


> ---
>  xen/arch/arm/mm.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index 474dfef..eaeb0c3 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -981,6 +981,8 @@ static int xenmem_add_to_physmap_one(
>              idx &= ~XENMAPIDX_grant_table_status;
>              if ( idx < nr_status_frames(d->grant_table) )
>                  mfn = virt_to_mfn(d->grant_table->status[idx]);
> +            else
> +                return -EINVAL;
>          }
>          else
>          {
> @@ -990,6 +992,8 @@ static int xenmem_add_to_physmap_one(
>  
>              if ( idx < nr_grant_frames(d->grant_table) )
>                  mfn = virt_to_mfn(d->grant_table->shared_raw[idx]);
> +            else
> +                return -EINVAL;
>          }
>          
>          d->arch.grant_table_gpfn[idx] = gpfn;
> @@ -999,6 +1003,8 @@ static int xenmem_add_to_physmap_one(
>      case XENMAPSPACE_shared_info:
>          if ( idx == 0 )
>              mfn = virt_to_mfn(d->shared_info);
> +        else
> +            return -EINVAL;
>          break;
>      case XENMAPSPACE_gmfn_foreign:
>      {
> -- 
> 1.8.3.1
>
Stefano Stabellini Oct. 24, 2013, 10:22 a.m. UTC | #2
On Wed, 23 Oct 2013, Julien Grall wrote:
> By default, the function add_to_physmap_one set mfn to 0. Some code paths that
> result to an error, continue and the map the mfn 0 (valid on ARM) to the
> slot given by the guest.
> 
> To fix the problem, return directly an error if sanity check has failed.
> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>


>  xen/arch/arm/mm.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index 474dfef..eaeb0c3 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -981,6 +981,8 @@ static int xenmem_add_to_physmap_one(
>              idx &= ~XENMAPIDX_grant_table_status;
>              if ( idx < nr_status_frames(d->grant_table) )
>                  mfn = virt_to_mfn(d->grant_table->status[idx]);
> +            else
> +                return -EINVAL;
>          }
>          else
>          {
> @@ -990,6 +992,8 @@ static int xenmem_add_to_physmap_one(
>  
>              if ( idx < nr_grant_frames(d->grant_table) )
>                  mfn = virt_to_mfn(d->grant_table->shared_raw[idx]);
> +            else
> +                return -EINVAL;
>          }
>          
>          d->arch.grant_table_gpfn[idx] = gpfn;
> @@ -999,6 +1003,8 @@ static int xenmem_add_to_physmap_one(
>      case XENMAPSPACE_shared_info:
>          if ( idx == 0 )
>              mfn = virt_to_mfn(d->shared_info);
> +        else
> +            return -EINVAL;
>          break;
>      case XENMAPSPACE_gmfn_foreign:
>      {
> -- 
> 1.8.3.1
>
Ian Campbell Oct. 24, 2013, 2 p.m. UTC | #3
On Wed, 2013-10-23 at 17:28 +0100, Julien Grall wrote:
> By default, the function add_to_physmap_one set mfn to 0. Some code paths that
> result to an error, continue and the map the mfn 0 (valid on ARM) to the
> slot given by the guest.
> 
> To fix the problem, return directly an error if sanity check has failed.
> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>

applied,thanks.
diff mbox

Patch

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 474dfef..eaeb0c3 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -981,6 +981,8 @@  static int xenmem_add_to_physmap_one(
             idx &= ~XENMAPIDX_grant_table_status;
             if ( idx < nr_status_frames(d->grant_table) )
                 mfn = virt_to_mfn(d->grant_table->status[idx]);
+            else
+                return -EINVAL;
         }
         else
         {
@@ -990,6 +992,8 @@  static int xenmem_add_to_physmap_one(
 
             if ( idx < nr_grant_frames(d->grant_table) )
                 mfn = virt_to_mfn(d->grant_table->shared_raw[idx]);
+            else
+                return -EINVAL;
         }
         
         d->arch.grant_table_gpfn[idx] = gpfn;
@@ -999,6 +1003,8 @@  static int xenmem_add_to_physmap_one(
     case XENMAPSPACE_shared_info:
         if ( idx == 0 )
             mfn = virt_to_mfn(d->shared_info);
+        else
+            return -EINVAL;
         break;
     case XENMAPSPACE_gmfn_foreign:
     {