diff mbox

[v2,2/2] ivshmem: add missing error exit(2)

Message ID 1370249911-19708-3-git-send-email-stefanha@redhat.com
State New
Headers show

Commit Message

Stefan Hajnoczi June 3, 2013, 8:58 a.m. UTC
If the user fails to specify 'chardev' or 'shm' then we cannot continue.
Exit right away so that we don't invoke shm_open(3) with a NULL pointer.

It would be nice to replace exit(1) with error returns in the PCI device
.init() function, but leave that for another patch since exit(1) is
currently used elsewhere.

Spotted by Coverity.

Cc: Cam Macdonell <cam@cs.ualberta.ca>
Cc: qemu-stable@nongnu.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/misc/ivshmem.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Eric Blake June 3, 2013, 12:26 p.m. UTC | #1
On 06/03/2013 02:58 AM, Stefan Hajnoczi wrote:
> If the user fails to specify 'chardev' or 'shm' then we cannot continue.
> Exit right away so that we don't invoke shm_open(3) with a NULL pointer.
> 
> It would be nice to replace exit(1) with error returns in the PCI device
> .init() function, but leave that for another patch since exit(1) is
> currently used elsewhere.
> 
> Spotted by Coverity.
> 
> Cc: Cam Macdonell <cam@cs.ualberta.ca>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  hw/misc/ivshmem.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index a19a6d6..5658f73 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -735,6 +735,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
>  
>          if (s->shmobj == NULL) {
>              fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
> +            exit(1);

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

However, I prefer exit(EXIT_FAILURE) rather than exit(1), to make it a
bit easier to grep for known failure exits.  Libvirt has a syntax
checker (taken from gnulib) that enforces such a style, if qemu would
like to adopt that style.
Stefan Hajnoczi June 3, 2013, 1:11 p.m. UTC | #2
On Mon, Jun 03, 2013 at 06:26:22AM -0600, Eric Blake wrote:
> On 06/03/2013 02:58 AM, Stefan Hajnoczi wrote:
> > If the user fails to specify 'chardev' or 'shm' then we cannot continue.
> > Exit right away so that we don't invoke shm_open(3) with a NULL pointer.
> > 
> > It would be nice to replace exit(1) with error returns in the PCI device
> > .init() function, but leave that for another patch since exit(1) is
> > currently used elsewhere.
> > 
> > Spotted by Coverity.
> > 
> > Cc: Cam Macdonell <cam@cs.ualberta.ca>
> > Cc: qemu-stable@nongnu.org
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >  hw/misc/ivshmem.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> > index a19a6d6..5658f73 100644
> > --- a/hw/misc/ivshmem.c
> > +++ b/hw/misc/ivshmem.c
> > @@ -735,6 +735,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
> >  
> >          if (s->shmobj == NULL) {
> >              fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
> > +            exit(1);
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> However, I prefer exit(EXIT_FAILURE) rather than exit(1), to make it a
> bit easier to grep for known failure exits.  Libvirt has a syntax
> checker (taken from gnulib) that enforces such a style, if qemu would
> like to adopt that style.

I like EXIT_FAILURE too but the rest of the file inconsistently uses
exit(1) and exit(-1).  I decided exit(1) was the least evil but the
longer term fix is to return instead of exiting.
Stefan Hajnoczi June 12, 2013, 7:22 a.m. UTC | #3
On Mon, Jun 03, 2013 at 10:58:31AM +0200, Stefan Hajnoczi wrote:
> If the user fails to specify 'chardev' or 'shm' then we cannot continue.
> Exit right away so that we don't invoke shm_open(3) with a NULL pointer.
> 
> It would be nice to replace exit(1) with error returns in the PCI device
> .init() function, but leave that for another patch since exit(1) is
> currently used elsewhere.
> 
> Spotted by Coverity.
> 
> Cc: Cam Macdonell <cam@cs.ualberta.ca>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  hw/misc/ivshmem.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index a19a6d6..5658f73 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -735,6 +735,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
>  
>          if (s->shmobj == NULL) {
>              fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
> +            exit(1);
>          }
>  
>          IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
> -- 
> 1.8.1.4
> 

Ping?
Andreas Färber June 12, 2013, 8:49 a.m. UTC | #4
Am 03.06.2013 15:11, schrieb Stefan Hajnoczi:
> On Mon, Jun 03, 2013 at 06:26:22AM -0600, Eric Blake wrote:
>> On 06/03/2013 02:58 AM, Stefan Hajnoczi wrote:
>>> If the user fails to specify 'chardev' or 'shm' then we cannot continue.
>>> Exit right away so that we don't invoke shm_open(3) with a NULL pointer.
>>>
>>> It would be nice to replace exit(1) with error returns in the PCI device
>>> .init() function, but leave that for another patch since exit(1) is
>>> currently used elsewhere.
>>>
>>> Spotted by Coverity.
>>>
>>> Cc: Cam Macdonell <cam@cs.ualberta.ca>
>>> Cc: qemu-stable@nongnu.org
>>> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
>>> ---
>>>  hw/misc/ivshmem.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
>>> index a19a6d6..5658f73 100644
>>> --- a/hw/misc/ivshmem.c
>>> +++ b/hw/misc/ivshmem.c
>>> @@ -735,6 +735,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
>>>  
>>>          if (s->shmobj == NULL) {
>>>              fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
>>> +            exit(1);
>>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>>
>> However, I prefer exit(EXIT_FAILURE) rather than exit(1), to make it a
>> bit easier to grep for known failure exits.  Libvirt has a syntax
>> checker (taken from gnulib) that enforces such a style, if qemu would
>> like to adopt that style.
> 
> I like EXIT_FAILURE too but the rest of the file inconsistently uses
> exit(1) and exit(-1).  I decided exit(1) was the least evil but the
> longer term fix is to return instead of exiting.

QOM realize would solve that, but similar to virtio the PCI qdev initfn
actually does something (allocating the config region among others) so
faces the same design questions of how to best inherit QOM methods as
currently being discussed. Shouldn't hold up a bug fix like this one.

Andreas
Michael Tokarev June 12, 2013, 9:18 a.m. UTC | #5
12.06.2013 11:22, Stefan Hajnoczi wrote:
>> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
>> index a19a6d6..5658f73 100644
>> --- a/hw/misc/ivshmem.c
>> +++ b/hw/misc/ivshmem.c
>> @@ -735,6 +735,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
>>  
>>          if (s->shmobj == NULL) {
>>              fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
>> +            exit(1);
>>          }
>>  
>>          IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
> 
> Ping?

Ow.  I missed it because part 1/2 were applied to scsi branch by
Paolo and I marked whole thread as "done".

Applied this 2/2 now to the trivial patches tree.

Thank you!

/mjt
diff mbox

Patch

diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index a19a6d6..5658f73 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -735,6 +735,7 @@  static int pci_ivshmem_init(PCIDevice *dev)
 
         if (s->shmobj == NULL) {
             fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
+            exit(1);
         }
 
         IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);