* [PATCH] xen/xenoprof: avoid division by 0
@ 2013-02-14 16:16 Tim Deegan
2013-02-14 16:34 ` Jan Beulich
0 siblings, 1 reply; 7+ messages in thread
From: Tim Deegan @ 2013-02-14 16:16 UTC (permalink / raw)
To: xen-devel
# HG changeset patch
# User Tim Deegan <tim@xen.org>
# Date 1360858577 0
# Node ID 68308aac7872c07631cb8424367907a11811ec3d
# Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
xen/xenoprof: avoid division by 0.
Signed-off-by: Tim Deegan <tim@xen.org>
diff -r 5a84cc531072 -r 68308aac7872 xen/common/xenoprof.c
--- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
+++ b/xen/common/xenoprof.c Thu Feb 14 16:16:17 2013 +0000
@@ -225,7 +225,7 @@ static int alloc_xenoprof_struct(
#endif
/* reduce max_samples if necessary to limit pages allocated */
- max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / nvcpu;
+ max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / (nvcpu ?: 1);
max_max_samples = ( (max_bufsize - bufsize) / i ) + 1;
if ( (unsigned)max_samples > max_max_samples )
max_samples = max_max_samples;
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xen/xenoprof: avoid division by 0
2013-02-14 16:16 [PATCH] xen/xenoprof: avoid division by 0 Tim Deegan
@ 2013-02-14 16:34 ` Jan Beulich
2013-02-14 16:50 ` Tim Deegan
0 siblings, 1 reply; 7+ messages in thread
From: Jan Beulich @ 2013-02-14 16:34 UTC (permalink / raw)
To: Tim Deegan; +Cc: xen-devel
>>> On 14.02.13 at 17:16, Tim Deegan <tim@xen.org> wrote:
> --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
> +++ b/xen/common/xenoprof.c Thu Feb 14 16:16:17 2013 +0000
> @@ -225,7 +225,7 @@ static int alloc_xenoprof_struct(
> #endif
>
> /* reduce max_samples if necessary to limit pages allocated */
> - max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / nvcpu;
> + max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / (nvcpu ?: 1);
> max_max_samples = ( (max_bufsize - bufsize) / i ) + 1;
> if ( (unsigned)max_samples > max_max_samples )
> max_samples = max_max_samples;
I think the function would better return an error in that case. After
all there's little point in setting up anything when we for sure don't
know how many vCPU-s a domain is going to have.
Jan
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xen/xenoprof: avoid division by 0
2013-02-14 16:34 ` Jan Beulich
@ 2013-02-14 16:50 ` Tim Deegan
2013-02-14 17:05 ` Jan Beulich
0 siblings, 1 reply; 7+ messages in thread
From: Tim Deegan @ 2013-02-14 16:50 UTC (permalink / raw)
To: Jan Beulich; +Cc: xen-devel
At 16:34 +0000 on 14 Feb (1360859678), Jan Beulich wrote:
> >>> On 14.02.13 at 17:16, Tim Deegan <tim@xen.org> wrote:
> > --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
> > +++ b/xen/common/xenoprof.c Thu Feb 14 16:16:17 2013 +0000
> > @@ -225,7 +225,7 @@ static int alloc_xenoprof_struct(
> > #endif
> >
> > /* reduce max_samples if necessary to limit pages allocated */
> > - max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / nvcpu;
> > + max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / (nvcpu ?: 1);
> > max_max_samples = ( (max_bufsize - bufsize) / i ) + 1;
> > if ( (unsigned)max_samples > max_max_samples )
> > max_samples = max_max_samples;
>
> I think the function would better return an error in that case. After
> all there's little point in setting up anything when we for sure don't
> know how many vCPU-s a domain is going to have.
Grand so:
# HG changeset patch
# Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
xen/xenoprof: avoid division by 0.
Signed-off-by: Tim Deegan <tim@xen.org>
diff -r 5a84cc531072 xen/common/xenoprof.c
--- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
+++ b/xen/common/xenoprof.c Thu Feb 14 16:48:49 2013 +0000
@@ -213,6 +213,9 @@ static int alloc_xenoprof_struct(
for_each_vcpu ( d, v )
nvcpu++;
+ if ( !nvcpu )
+ return -EINVAL;
+
bufsize = sizeof(struct xenoprof_buf);
i = sizeof(struct event_log);
#ifdef CONFIG_COMPAT
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xen/xenoprof: avoid division by 0
2013-02-14 16:50 ` Tim Deegan
@ 2013-02-14 17:05 ` Jan Beulich
2013-02-14 17:10 ` Tim Deegan
0 siblings, 1 reply; 7+ messages in thread
From: Jan Beulich @ 2013-02-14 17:05 UTC (permalink / raw)
To: Tim Deegan; +Cc: xen-devel
>>> On 14.02.13 at 17:50, Tim Deegan <tim@xen.org> wrote:
> At 16:34 +0000 on 14 Feb (1360859678), Jan Beulich wrote:
>> >>> On 14.02.13 at 17:16, Tim Deegan <tim@xen.org> wrote:
>> > --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
>> > +++ b/xen/common/xenoprof.c Thu Feb 14 16:16:17 2013 +0000
>> > @@ -225,7 +225,7 @@ static int alloc_xenoprof_struct(
>> > #endif
>> >
>> > /* reduce max_samples if necessary to limit pages allocated */
>> > - max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / nvcpu;
>> > + max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / (nvcpu ?: 1);
>> > max_max_samples = ( (max_bufsize - bufsize) / i ) + 1;
>> > if ( (unsigned)max_samples > max_max_samples )
>> > max_samples = max_max_samples;
>>
>> I think the function would better return an error in that case. After
>> all there's little point in setting up anything when we for sure don't
>> know how many vCPU-s a domain is going to have.
>
> Grand so:
>
> # HG changeset patch
> # Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
> xen/xenoprof: avoid division by 0.
>
> Signed-off-by: Tim Deegan <tim@xen.org>
>
> diff -r 5a84cc531072 xen/common/xenoprof.c
> --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
> +++ b/xen/common/xenoprof.c Thu Feb 14 16:48:49 2013 +0000
> @@ -213,6 +213,9 @@ static int alloc_xenoprof_struct(
> for_each_vcpu ( d, v )
> nvcpu++;
>
> + if ( !nvcpu )
> + return -EINVAL;
Missing some cleanup here? Or move the preceding loop and this
addition to the top of the function?
Jan
> +
> bufsize = sizeof(struct xenoprof_buf);
> i = sizeof(struct event_log);
> #ifdef CONFIG_COMPAT
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xen/xenoprof: avoid division by 0
2013-02-14 17:05 ` Jan Beulich
@ 2013-02-14 17:10 ` Tim Deegan
2013-02-15 8:10 ` Jan Beulich
0 siblings, 1 reply; 7+ messages in thread
From: Tim Deegan @ 2013-02-14 17:10 UTC (permalink / raw)
To: Jan Beulich; +Cc: xen-devel
At 17:05 +0000 on 14 Feb (1360861530), Jan Beulich wrote:
> >>> On 14.02.13 at 17:50, Tim Deegan <tim@xen.org> wrote:
> > At 16:34 +0000 on 14 Feb (1360859678), Jan Beulich wrote:
> >> >>> On 14.02.13 at 17:16, Tim Deegan <tim@xen.org> wrote:
> >> > --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
> >> > +++ b/xen/common/xenoprof.c Thu Feb 14 16:16:17 2013 +0000
> >> > @@ -225,7 +225,7 @@ static int alloc_xenoprof_struct(
> >> > #endif
> >> >
> >> > /* reduce max_samples if necessary to limit pages allocated */
> >> > - max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / nvcpu;
> >> > + max_bufsize = (MAX_OPROF_SHARED_PAGES * PAGE_SIZE) / (nvcpu ?: 1);
> >> > max_max_samples = ( (max_bufsize - bufsize) / i ) + 1;
> >> > if ( (unsigned)max_samples > max_max_samples )
> >> > max_samples = max_max_samples;
> >>
> >> I think the function would better return an error in that case. After
> >> all there's little point in setting up anything when we for sure don't
> >> know how many vCPU-s a domain is going to have.
> >
> > Grand so:
> >
> > # HG changeset patch
> > # Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
> > xen/xenoprof: avoid division by 0.
> >
> > Signed-off-by: Tim Deegan <tim@xen.org>
> >
> > diff -r 5a84cc531072 xen/common/xenoprof.c
> > --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
> > +++ b/xen/common/xenoprof.c Thu Feb 14 16:48:49 2013 +0000
> > @@ -213,6 +213,9 @@ static int alloc_xenoprof_struct(
> > for_each_vcpu ( d, v )
> > nvcpu++;
> >
> > + if ( !nvcpu )
> > + return -EINVAL;
>
> Missing some cleanup here? Or move the preceding loop and this
> addition to the top of the function?
D'oh, yes. Trying again:
# HG changeset patch
# Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
xen/xenoprof: avoid division by 0.
Signed-off-by: Tim Deegan <tim@xen.org>
diff -r 5a84cc531072 xen/common/xenoprof.c
--- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
+++ b/xen/common/xenoprof.c Thu Feb 14 17:07:41 2013 +0000
@@ -193,6 +193,13 @@ static int alloc_xenoprof_struct(
unsigned max_max_samples;
int i;
+ nvcpu = 0;
+ for_each_vcpu ( d, v )
+ nvcpu++;
+
+ if ( !nvcpu )
+ return -EINVAL;
+
d->xenoprof = xzalloc(struct xenoprof);
if ( d->xenoprof == NULL )
{
@@ -209,10 +216,6 @@ static int alloc_xenoprof_struct(
return -ENOMEM;
}
- nvcpu = 0;
- for_each_vcpu ( d, v )
- nvcpu++;
-
bufsize = sizeof(struct xenoprof_buf);
i = sizeof(struct event_log);
#ifdef CONFIG_COMPAT
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xen/xenoprof: avoid division by 0
2013-02-14 17:10 ` Tim Deegan
@ 2013-02-15 8:10 ` Jan Beulich
2013-02-15 8:24 ` Keir Fraser
0 siblings, 1 reply; 7+ messages in thread
From: Jan Beulich @ 2013-02-15 8:10 UTC (permalink / raw)
To: Tim Deegan; +Cc: xen-devel
>>> On 14.02.13 at 18:10, Tim Deegan <tim@xen.org> wrote:
> # HG changeset patch
> # Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
> xen/xenoprof: avoid division by 0.
>
> Signed-off-by: Tim Deegan <tim@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
> diff -r 5a84cc531072 xen/common/xenoprof.c
> --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
> +++ b/xen/common/xenoprof.c Thu Feb 14 17:07:41 2013 +0000
> @@ -193,6 +193,13 @@ static int alloc_xenoprof_struct(
> unsigned max_max_samples;
> int i;
>
> + nvcpu = 0;
> + for_each_vcpu ( d, v )
> + nvcpu++;
> +
> + if ( !nvcpu )
> + return -EINVAL;
> +
> d->xenoprof = xzalloc(struct xenoprof);
> if ( d->xenoprof == NULL )
> {
> @@ -209,10 +216,6 @@ static int alloc_xenoprof_struct(
> return -ENOMEM;
> }
>
> - nvcpu = 0;
> - for_each_vcpu ( d, v )
> - nvcpu++;
> -
> bufsize = sizeof(struct xenoprof_buf);
> i = sizeof(struct event_log);
> #ifdef CONFIG_COMPAT
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xen/xenoprof: avoid division by 0
2013-02-15 8:10 ` Jan Beulich
@ 2013-02-15 8:24 ` Keir Fraser
0 siblings, 0 replies; 7+ messages in thread
From: Keir Fraser @ 2013-02-15 8:24 UTC (permalink / raw)
To: Jan Beulich, Tim Deegan; +Cc: xen-devel
On 15/02/2013 08:10, "Jan Beulich" <JBeulich@suse.com> wrote:
>>>> On 14.02.13 at 18:10, Tim Deegan <tim@xen.org> wrote:
>> # HG changeset patch
>> # Parent 5a84cc531072378e6e5ff89b4c0e9a35000dc56f
>> xen/xenoprof: avoid division by 0.
>>
>> Signed-off-by: Tim Deegan <tim@xen.org>
>
> Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
>> diff -r 5a84cc531072 xen/common/xenoprof.c
>> --- a/xen/common/xenoprof.c Thu Feb 14 15:46:56 2013 +0000
>> +++ b/xen/common/xenoprof.c Thu Feb 14 17:07:41 2013 +0000
>> @@ -193,6 +193,13 @@ static int alloc_xenoprof_struct(
>> unsigned max_max_samples;
>> int i;
>>
>> + nvcpu = 0;
>> + for_each_vcpu ( d, v )
>> + nvcpu++;
>> +
>> + if ( !nvcpu )
>> + return -EINVAL;
>> +
>> d->xenoprof = xzalloc(struct xenoprof);
>> if ( d->xenoprof == NULL )
>> {
>> @@ -209,10 +216,6 @@ static int alloc_xenoprof_struct(
>> return -ENOMEM;
>> }
>>
>> - nvcpu = 0;
>> - for_each_vcpu ( d, v )
>> - nvcpu++;
>> -
>> bufsize = sizeof(struct xenoprof_buf);
>> i = sizeof(struct event_log);
>> #ifdef CONFIG_COMPAT
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-02-15 8:24 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-02-14 16:16 [PATCH] xen/xenoprof: avoid division by 0 Tim Deegan
2013-02-14 16:34 ` Jan Beulich
2013-02-14 16:50 ` Tim Deegan
2013-02-14 17:05 ` Jan Beulich
2013-02-14 17:10 ` Tim Deegan
2013-02-15 8:10 ` Jan Beulich
2013-02-15 8:24 ` Keir Fraser
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