2019-01-31 01:07:54

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
int stuff;
struct boo entry[];
};

instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
net/sunrpc/xprtrdma/verbs.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 4994e75945b8..9e8cf7456840 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -811,8 +811,7 @@ static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
{
struct rpcrdma_sendctx *sc;

- sc = kzalloc(sizeof(*sc) +
- ia->ri_max_send_sges * sizeof(struct ib_sge),
+ sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
GFP_KERNEL);
if (!sc)
return NULL;
--
2.20.1



2019-01-31 14:11:59

by Chuck Lever

[permalink] [raw]
Subject: Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()



> On Jan 30, 2019, at 7:46 PM, Gustavo A. R. Silva <[email protected]> wrote:
>
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> struct boo entry[];
> };
>
> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Reviewed-by: Chuck Lever <[email protected]>


> ---
> net/sunrpc/xprtrdma/verbs.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
> index 4994e75945b8..9e8cf7456840 100644
> --- a/net/sunrpc/xprtrdma/verbs.c
> +++ b/net/sunrpc/xprtrdma/verbs.c
> @@ -811,8 +811,7 @@ static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
> {
> struct rpcrdma_sendctx *sc;
>
> - sc = kzalloc(sizeof(*sc) +
> - ia->ri_max_send_sges * sizeof(struct ib_sge),
> + sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
> GFP_KERNEL);
> if (!sc)
> return NULL;
> --
> 2.20.1
>

--
Chuck Lever




2019-02-08 04:13:26

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()



On 1/31/19 8:11 AM, Chuck Lever wrote:
>
>
>> On Jan 30, 2019, at 7:46 PM, Gustavo A. R. Silva <[email protected]> wrote:
>>
>> One of the more common cases of allocation size calculations is finding
>> the size of a structure that has a zero-sized array at the end, along
>> with memory for some number of elements for that array. For example:
>>
>> struct foo {
>> int stuff;
>> struct boo entry[];
>> };
>>
>> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
>>
>> Instead of leaving these open-coded and prone to type mistakes, we can
>> now use the new struct_size() helper:
>>
>> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>>
>> This code was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> Reviewed-by: Chuck Lever <[email protected]>
>

Thanks, Chuck.

--
Gustavo

2019-03-28 21:02:26

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()

Hi all,

Friendly ping:

Who can take this?

Thanks
--
Gustavo

On 1/31/19 8:11 AM, Chuck Lever wrote:
>
>
>> On Jan 30, 2019, at 7:46 PM, Gustavo A. R. Silva <[email protected]> wrote:
>>
>> One of the more common cases of allocation size calculations is finding
>> the size of a structure that has a zero-sized array at the end, along
>> with memory for some number of elements for that array. For example:
>>
>> struct foo {
>> int stuff;
>> struct boo entry[];
>> };
>>
>> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
>>
>> Instead of leaving these open-coded and prone to type mistakes, we can
>> now use the new struct_size() helper:
>>
>> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>>
>> This code was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> Reviewed-by: Chuck Lever <[email protected]>
>
>
>> ---
>> net/sunrpc/xprtrdma/verbs.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
>> index 4994e75945b8..9e8cf7456840 100644
>> --- a/net/sunrpc/xprtrdma/verbs.c
>> +++ b/net/sunrpc/xprtrdma/verbs.c
>> @@ -811,8 +811,7 @@ static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
>> {
>> struct rpcrdma_sendctx *sc;
>>
>> - sc = kzalloc(sizeof(*sc) +
>> - ia->ri_max_send_sges * sizeof(struct ib_sge),
>> + sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
>> GFP_KERNEL);
>> if (!sc)
>> return NULL;
>> --
>> 2.20.1
>>
>
> --
> Chuck Lever
>
>
>

2019-05-23 23:03:40

by Chuck Lever

[permalink] [raw]
Subject: Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()

Hi Gustavo-

Anna is supposed to take patches for xprtrdma/ .


> On May 23, 2019, at 6:36 PM, Gustavo A. R. Silva <[email protected]> wrote:
>
> Hi Dave,
>
> I wonder if you can take this patch.
>
> Thanks
> --
> Gustavo
>
> On 3/28/19 3:41 PM, Gustavo A. R. Silva wrote:
>> Hi all,
>>
>> Friendly ping:
>>
>> Who can take this?
>>
>> Thanks
>> --
>> Gustavo
>>
>> On 1/31/19 8:11 AM, Chuck Lever wrote:
>>>
>>>
>>>> On Jan 30, 2019, at 7:46 PM, Gustavo A. R. Silva <[email protected]> wrote:
>>>>
>>>> One of the more common cases of allocation size calculations is finding
>>>> the size of a structure that has a zero-sized array at the end, along
>>>> with memory for some number of elements for that array. For example:
>>>>
>>>> struct foo {
>>>> int stuff;
>>>> struct boo entry[];
>>>> };
>>>>
>>>> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
>>>>
>>>> Instead of leaving these open-coded and prone to type mistakes, we can
>>>> now use the new struct_size() helper:
>>>>
>>>> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>>>>
>>>> This code was detected with the help of Coccinelle.
>>>>
>>>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>>>
>>> Reviewed-by: Chuck Lever <[email protected]>
>>>
>>>
>>>> ---
>>>> net/sunrpc/xprtrdma/verbs.c | 3 +--
>>>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>>>
>>>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
>>>> index 4994e75945b8..9e8cf7456840 100644
>>>> --- a/net/sunrpc/xprtrdma/verbs.c
>>>> +++ b/net/sunrpc/xprtrdma/verbs.c
>>>> @@ -811,8 +811,7 @@ static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
>>>> {
>>>> struct rpcrdma_sendctx *sc;
>>>>
>>>> - sc = kzalloc(sizeof(*sc) +
>>>> - ia->ri_max_send_sges * sizeof(struct ib_sge),
>>>> + sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
>>>> GFP_KERNEL);
>>>> if (!sc)
>>>> return NULL;
>>>> --
>>>> 2.20.1
>>>>
>>>
>>> --
>>> Chuck Lever
>>>
>>>
>>>

--
Chuck Lever



2019-05-23 23:33:13

by David Miller

[permalink] [raw]
Subject: Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()

From: "Gustavo A. R. Silva" <[email protected]>
Date: Thu, 23 May 2019 17:36:00 -0500

> Hi Dave,
>
> I wonder if you can take this patch.

The sunrpc/nfs maintainer should take this. I never take patches in that
area.

2019-05-28 13:56:48

by Anna Schumaker

[permalink] [raw]
Subject: Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()


On Thu, 2019-05-23 at 18:43 -0500, Gustavo A. R. Silva wrote:
>
> On 5/23/19 6:32 PM, David Miller wrote:
> > From: "Gustavo A. R. Silva" <[email protected]>
> > Date: Thu, 23 May 2019 17:36:00 -0500
> >
> > > Hi Dave,
> > >
> > > I wonder if you can take this patch.
> >
> > The sunrpc/nfs maintainer should take this. I never take patches in that
> > area.
> >
>
> Yep. Chuck just let me know that Anna is who take these patches.
>
> Hopefully, she will take this one soon.

I've applied this to push out later in the week. Thanks for pointing it out to
me!

Anna

>
> Thanks
> --
> Gustavo