* [PATCH] dm-switch: use struct_size() in kzalloc()
@ 2019-01-08 16:02 Gustavo A. R. Silva
2019-02-21 15:27 ` Gustavo A. R. Silva
0 siblings, 1 reply; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-08 16:02 UTC (permalink / raw)
To: Alasdair Kergon, Mike Snitzer, dm-devel; +Cc: linux-kernel, Gustavo A. R. Silva
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;
void *entry[];
};
instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, 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 <gustavo@embeddedor.com>
---
drivers/md/dm-switch.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index fae35caf3672..8a0f057b8122 100644
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -61,8 +61,7 @@ static struct switch_ctx *alloc_switch_ctx(struct dm_target *ti, unsigned nr_pat
{
struct switch_ctx *sctx;
- sctx = kzalloc(sizeof(struct switch_ctx) + nr_paths * sizeof(struct switch_path),
- GFP_KERNEL);
+ sctx = kzalloc(struct_size(sctx, path_list, nr_paths), GFP_KERNEL);
if (!sctx)
return NULL;
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] dm-switch: use struct_size() in kzalloc()
2019-01-08 16:02 [PATCH] dm-switch: use struct_size() in kzalloc() Gustavo A. R. Silva
@ 2019-02-21 15:27 ` Gustavo A. R. Silva
2019-02-21 15:40 ` Mike Snitzer
0 siblings, 1 reply; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-02-21 15:27 UTC (permalink / raw)
To: Alasdair Kergon, Mike Snitzer, dm-devel; +Cc: linux-kernel
Hi all,
Friendly ping:
Who can take this?
Thanks
--
Gustavo
On 1/8/19 10:02 AM, Gustavo A. R. Silva 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;
> void *entry[];
> };
>
> instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, 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 <gustavo@embeddedor.com>
> ---
> drivers/md/dm-switch.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
> index fae35caf3672..8a0f057b8122 100644
> --- a/drivers/md/dm-switch.c
> +++ b/drivers/md/dm-switch.c
> @@ -61,8 +61,7 @@ static struct switch_ctx *alloc_switch_ctx(struct dm_target *ti, unsigned nr_pat
> {
> struct switch_ctx *sctx;
>
> - sctx = kzalloc(sizeof(struct switch_ctx) + nr_paths * sizeof(struct switch_path),
> - GFP_KERNEL);
> + sctx = kzalloc(struct_size(sctx, path_list, nr_paths), GFP_KERNEL);
> if (!sctx)
> return NULL;
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: dm-switch: use struct_size() in kzalloc()
2019-02-21 15:27 ` Gustavo A. R. Silva
@ 2019-02-21 15:40 ` Mike Snitzer
2019-02-21 15:43 ` Gustavo A. R. Silva
0 siblings, 1 reply; 4+ messages in thread
From: Mike Snitzer @ 2019-02-21 15:40 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: Alasdair Kergon, dm-devel, linux-kernel
On Thu, Feb 21 2019 at 10:27am -0500,
Gustavo A. R. Silva <gustavo@embeddedor.com> wrote:
> Hi all,
>
> Friendly ping:
>
> Who can take this?
I've picked it up for 5.1:
https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-5.1&id=042f96ad4c5a369307df2a840fd943a4b080c3d1
Thanks,
Mike
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: dm-switch: use struct_size() in kzalloc()
2019-02-21 15:40 ` Mike Snitzer
@ 2019-02-21 15:43 ` Gustavo A. R. Silva
0 siblings, 0 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-02-21 15:43 UTC (permalink / raw)
To: Mike Snitzer; +Cc: Alasdair Kergon, dm-devel, linux-kernel
On 2/21/19 9:40 AM, Mike Snitzer wrote:
> On Thu, Feb 21 2019 at 10:27am -0500,
> Gustavo A. R. Silva <gustavo@embeddedor.com> wrote:
>
>> Hi all,
>>
>> Friendly ping:
>>
>> Who can take this?
>
> I've picked it up for 5.1:
> https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-5.1&id=042f96ad4c5a369307df2a840fd943a4b080c3d1
>
Great. :)
Thank you, Mike.
--
Gustavo
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-02-21 15:43 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-01-08 16:02 [PATCH] dm-switch: use struct_size() in kzalloc() Gustavo A. R. Silva
2019-02-21 15:27 ` Gustavo A. R. Silva
2019-02-21 15:40 ` Mike Snitzer
2019-02-21 15:43 ` Gustavo A. R. Silva
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