[Qemu-devel] [PATCH] block: Assert validity of BdrvActionOps

[Qemu-devel] [PATCH] block: Assert validity of BdrvActionOps

[Max Reitz]

In qmp_transaction, assert that the BdrvActionOps to be used is actually
valid.

This assertion failing is very improbable, however, it might happen, if
a new TransactionActionKind is introduced "out of order" and the
actions[] array is not updated.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index 07dac05..14a0bb1 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1102,6 +1102,8 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
         assert(dev_info->kind < ARRAY_SIZE(actions));
 
         ops = &actions[dev_info->kind];
+        assert(ops->instance_size > 0);
+
         state = g_malloc0(ops->instance_size);
         state->ops = ops;
         state->action = dev_info;
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH] block: Assert validity of BdrvActionOps

[Eric Blake]

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On 09/12/2013 06:57 AM, Max Reitz wrote:
> In qmp_transaction, assert that the BdrvActionOps to be used is actually
> valid.
> 
> This assertion failing is very improbable, however, it might happen, if
> a new TransactionActionKind is introduced "out of order" and the
> actions[] array is not updated.

All of which would be a programmer bug, so assert is correct.

> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  blockdev.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/blockdev.c b/blockdev.c
> index 07dac05..14a0bb1 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1102,6 +1102,8 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>          assert(dev_info->kind < ARRAY_SIZE(actions));
>  
>          ops = &actions[dev_info->kind];
> +        assert(ops->instance_size > 0);

Bikeshedding: assert(ops->instance_size) is slightly less typing (but
not enough to warrant a respin).

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] block: Assert validity of BdrvActionOps

[Kevin Wolf]

Am 12.09.2013 um 14:57 hat Max Reitz geschrieben:
> In qmp_transaction, assert that the BdrvActionOps to be used is actually
> valid.
> 
> This assertion failing is very improbable, however, it might happen, if
> a new TransactionActionKind is introduced "out of order" and the
> actions[] array is not updated.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Thanks, applied to the block branch.

Kevin