2019-11-05 15:52:03

by Toke Høiland-Jørgensen

Subject: [PATCH] net/fq_impl: Switch to kvmalloc() for memory allocation

The FQ implementation used by mac80211 allocates memory using kmalloc(),
which can fail; and Johannes reported that this actually happens in
practice.

To avoid this, switch the allocation to kvmalloc() instead; this also
brings fq_impl in line with all the FQ qdiscs.

Fixes: 557fc4a09803 ("fq: add fair queuing framework")
Reported-by: Johannes Berg <[email protected]>
Signed-off-by: Toke Høiland-Jørgensen <[email protected]>
---
include/net/fq_impl.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
index 107c0d700ed6..d3873db91c71 100644
--- a/include/net/fq_impl.h
+++ b/include/net/fq_impl.h
@@ -313,7 +313,7 @@ static int fq_init(struct fq *fq, int flows_cnt)
fq->limit = 8192;
fq->memory_limit = 16 << 20; /* 16 MBytes */

- fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
+ fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
if (!fq->flows)
return -ENOMEM;

--
2.23.0

2019-11-05 15:53:59

by Johannes Berg

Subject: Re: [PATCH] net/fq_impl: Switch to kvmalloc() for memory allocation

On Tue, 2019-11-05 at 16:49 +0100, Toke Høiland-Jørgensen wrote:
> The FQ implementation used by mac80211 allocates memory using kmalloc(),
> which can fail; and Johannes reported that this actually happens in
> practice.
>
> To avoid this, switch the allocation to kvmalloc() instead; this also
> brings fq_impl in line with all the FQ qdiscs.
>
> Fixes: 557fc4a09803 ("fq: add fair queuing framework")
> Reported-by: Johannes Berg <[email protected]>
> Signed-off-by: Toke Høiland-Jørgensen <[email protected]>
> ---
> include/net/fq_impl.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
> index 107c0d700ed6..d3873db91c71 100644
> --- a/include/net/fq_impl.h
> +++ b/include/net/fq_impl.h
> @@ -313,7 +313,7 @@ static int fq_init(struct fq *fq, int flows_cnt)
> fq->limit = 8192;
> fq->memory_limit = 16 << 20; /* 16 MBytes */
>
> - fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
> + fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);

You need a corresponding kvfree(), no?

johannes

2019-11-05 15:59:23

by Toke Høiland-Jørgensen

Subject: Re: [PATCH] net/fq_impl: Switch to kvmalloc() for memory allocation

Johannes Berg <[email protected]> writes:

> On Tue, 2019-11-05 at 16:49 +0100, Toke Høiland-Jørgensen wrote:
>> The FQ implementation used by mac80211 allocates memory using kmalloc(),
>> which can fail; and Johannes reported that this actually happens in
>> practice.
>>
>> To avoid this, switch the allocation to kvmalloc() instead; this also
>> brings fq_impl in line with all the FQ qdiscs.
>>
>> Fixes: 557fc4a09803 ("fq: add fair queuing framework")
>> Reported-by: Johannes Berg <[email protected]>
>> Signed-off-by: Toke Høiland-Jørgensen <[email protected]>
>> ---
>> include/net/fq_impl.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
>> index 107c0d700ed6..d3873db91c71 100644
>> --- a/include/net/fq_impl.h
>> +++ b/include/net/fq_impl.h
>> @@ -313,7 +313,7 @@ static int fq_init(struct fq *fq, int flows_cnt)
>> fq->limit = 8192;
>> fq->memory_limit = 16 << 20; /* 16 MBytes */
>>
>> - fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
>> + fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
>
> You need a corresponding kvfree(), no?

Oh, right, of course; silly me. Guess I was a bit too trigger-happy on
the nice one-character patch ;)

Will send a v2

-Toke

2019-11-05 16:00:40

by Johannes Berg

Subject: Re: [PATCH] net/fq_impl: Switch to kvmalloc() for memory allocation

On Tue, 2019-11-05 at 16:56 +0100, Toke Høiland-Jørgensen wrote:
>
> Oh, right, of course; silly me. Guess I was a bit too trigger-happy on
> the nice one-character patch ;)
>

I guess two characters is still pretty good ;)

johannes

2019-11-05 16:09:40

by Toke Høiland-Jørgensen

Subject: Re: [PATCH] net/fq_impl: Switch to kvmalloc() for memory allocation

Johannes Berg <[email protected]> writes:

> On Tue, 2019-11-05 at 16:56 +0100, Toke Høiland-Jørgensen wrote:
>>
>> Oh, right, of course; silly me. Guess I was a bit too trigger-happy on
>> the nice one-character patch ;)
>>
>
> I guess two characters is still pretty good ;)

Hehe, yeah, I can live with that ;)

-Toke