* [patch] vhost: NULL vs ERR_PTR bug
@ 2015-07-15 11:16 Dan Carpenter
2015-07-15 11:28 ` Michael S. Tsirkin
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2015-07-15 11:16 UTC (permalink / raw)
To: Michael S. Tsirkin, Igor Mammedov; +Cc: kernel-janitors, kvm, virtualization
There is only one caller for vhost_kvzalloc() and it expects NULL on
allocation failure. Most people would probably expect that so let's
change ERR_PTR(-ENOMEM) to NULL.
Fixes: 4de7255f7d2b ('vhost: extend memory regions allocation to vmalloc')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a9fe859..99d613b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -686,7 +686,7 @@ static void *vhost_kvzalloc(unsigned long size)
if (!n) {
n = vzalloc(size);
if (!n)
- return ERR_PTR(-ENOMEM);
+ return NULL;
}
return n;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [patch] vhost: NULL vs ERR_PTR bug
2015-07-15 11:16 [patch] vhost: NULL vs ERR_PTR bug Dan Carpenter
@ 2015-07-15 11:28 ` Michael S. Tsirkin
2015-07-15 11:35 ` walter harms
0 siblings, 1 reply; 6+ messages in thread
From: Michael S. Tsirkin @ 2015-07-15 11:28 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Igor Mammedov, kvm, virtualization, kernel-janitors
On Wed, Jul 15, 2015 at 02:16:59PM +0300, Dan Carpenter wrote:
> There is only one caller for vhost_kvzalloc() and it expects NULL on
> allocation failure. Most people would probably expect that so let's
> change ERR_PTR(-ENOMEM) to NULL.
>
> Fixes: 4de7255f7d2b ('vhost: extend memory regions allocation to vmalloc')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Ouch. Thanks a lot for noticing this, and it's a good thing
you did before Linus merged it.
I'll squash this into Igor's patch and redo my pull request.
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index a9fe859..99d613b 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -686,7 +686,7 @@ static void *vhost_kvzalloc(unsigned long size)
> if (!n) {
> n = vzalloc(size);
> if (!n)
> - return ERR_PTR(-ENOMEM);
> + return NULL;
> }
> return n;
> }
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [patch] vhost: NULL vs ERR_PTR bug
2015-07-15 11:28 ` Michael S. Tsirkin
@ 2015-07-15 11:35 ` walter harms
2015-07-15 11:41 ` Dan Carpenter
2015-07-15 14:21 ` Julia Lawall
0 siblings, 2 replies; 6+ messages in thread
From: walter harms @ 2015-07-15 11:35 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Dan Carpenter, Igor Mammedov, kvm, virtualization,
kernel-janitors
Am 15.07.2015 13:28, schrieb Michael S. Tsirkin:
> On Wed, Jul 15, 2015 at 02:16:59PM +0300, Dan Carpenter wrote:
>> There is only one caller for vhost_kvzalloc() and it expects NULL on
>> allocation failure. Most people would probably expect that so let's
>> change ERR_PTR(-ENOMEM) to NULL.
>>
>> Fixes: 4de7255f7d2b ('vhost: extend memory regions allocation to vmalloc')
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> Ouch. Thanks a lot for noticing this, and it's a good thing
> you did before Linus merged it.
> I'll squash this into Igor's patch and redo my pull request.
>
Is this function needed at all ?
e.g. I followed vzalloc() to __vmalloc_node_range()
a check for size=0 seems to be done there.
re,
wh
>>
>> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>> index a9fe859..99d613b 100644
>> --- a/drivers/vhost/vhost.c
>> +++ b/drivers/vhost/vhost.c
>> @@ -686,7 +686,7 @@ static void *vhost_kvzalloc(unsigned long size)
>> if (!n) {
>> n = vzalloc(size);
>> if (!n)
>> - return ERR_PTR(-ENOMEM);
>> + return NULL;
>> }
>> return n;
>> }
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [patch] vhost: NULL vs ERR_PTR bug
2015-07-15 11:35 ` walter harms
@ 2015-07-15 11:41 ` Dan Carpenter
2015-07-15 14:21 ` Julia Lawall
1 sibling, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2015-07-15 11:41 UTC (permalink / raw)
To: walter harms
Cc: Igor Mammedov, virtualization, kernel-janitors, kvm,
Michael S. Tsirkin
On Wed, Jul 15, 2015 at 01:35:16PM +0200, walter harms wrote:
> Is this function needed at all ?
>
It tries to kmalloc() memory and if it can't then it tries to vmalloc()
it. There are a bunch of these functions. Eventually someone should
put one in a common header.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [patch] vhost: NULL vs ERR_PTR bug
2015-07-15 11:35 ` walter harms
2015-07-15 11:41 ` Dan Carpenter
@ 2015-07-15 14:21 ` Julia Lawall
2015-07-15 14:40 ` Dan Carpenter
1 sibling, 1 reply; 6+ messages in thread
From: Julia Lawall @ 2015-07-15 14:21 UTC (permalink / raw)
To: walter harms
Cc: Michael S. Tsirkin, Dan Carpenter, Igor Mammedov, kvm,
virtualization, kernel-janitors
On Wed, 15 Jul 2015, walter harms wrote:
>
>
> Am 15.07.2015 13:28, schrieb Michael S. Tsirkin:
> > On Wed, Jul 15, 2015 at 02:16:59PM +0300, Dan Carpenter wrote:
> >> There is only one caller for vhost_kvzalloc() and it expects NULL on
> >> allocation failure. Most people would probably expect that so let's
> >> change ERR_PTR(-ENOMEM) to NULL.
> >>
> >> Fixes: 4de7255f7d2b ('vhost: extend memory regions allocation to vmalloc')
> >> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >
> > Ouch. Thanks a lot for noticing this, and it's a good thing
> > you did before Linus merged it.
> > I'll squash this into Igor's patch and redo my pull request.
> >
>
> Is this function needed at all ?
>
> e.g. I followed vzalloc() to __vmalloc_node_range()
>
> a check for size=0 seems to be done there.
At least it looks like one could return the result of vzalloc directly?
julia
>
> re,
> wh
>
>
> >>
> >> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> >> index a9fe859..99d613b 100644
> >> --- a/drivers/vhost/vhost.c
> >> +++ b/drivers/vhost/vhost.c
> >> @@ -686,7 +686,7 @@ static void *vhost_kvzalloc(unsigned long size)
> >> if (!n) {
> >> n = vzalloc(size);
> >> if (!n)
> >> - return ERR_PTR(-ENOMEM);
> >> + return NULL;
> >> }
> >> return n;
> >> }
> > --
> > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [patch] vhost: NULL vs ERR_PTR bug
2015-07-15 14:21 ` Julia Lawall
@ 2015-07-15 14:40 ` Dan Carpenter
0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2015-07-15 14:40 UTC (permalink / raw)
To: Julia Lawall
Cc: kvm, Michael S. Tsirkin, kernel-janitors, virtualization,
Igor Mammedov, walter harms
On Wed, Jul 15, 2015 at 10:21:12AM -0400, Julia Lawall wrote:
> At least it looks like one could return the result of vzalloc directly?
>
> julia
That's a true... I was tempted to re-write it a bit. I think one of
the Lustre people are eventually going to export this function and we
will delete this one.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
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2015-07-15 11:16 [patch] vhost: NULL vs ERR_PTR bug Dan Carpenter
2015-07-15 11:28 ` Michael S. Tsirkin
2015-07-15 11:35 ` walter harms
2015-07-15 11:41 ` Dan Carpenter
2015-07-15 14:21 ` Julia Lawall
2015-07-15 14:40 ` Dan Carpenter
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