* [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc()
@ 2019-01-07 17:33 Gustavo A. R. Silva
2019-01-08 5:00 ` Viresh Kumar
0 siblings, 1 reply; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-07 17:33 UTC (permalink / raw)
To: Rafael J. Wysocki, Viresh Kumar
Cc: linux-pm, 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/cpufreq/e_powersaver.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c
index 60bea302abbe..2d3ef208dd70 100644
--- a/drivers/cpufreq/e_powersaver.c
+++ b/drivers/cpufreq/e_powersaver.c
@@ -323,9 +323,8 @@ static int eps_cpu_init(struct cpufreq_policy *policy)
states = 2;
/* Allocate private data and frequency table for current cpu */
- centaur = kzalloc(sizeof(*centaur)
- + (states + 1) * sizeof(struct cpufreq_frequency_table),
- GFP_KERNEL);
+ centaur = kzalloc(struct_size(centaur, freq_table, states + 1),
+ GFP_KERNEL);
if (!centaur)
return -ENOMEM;
eps_cpu[0] = centaur;
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc()
2019-01-07 17:33 [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc() Gustavo A. R. Silva
@ 2019-01-08 5:00 ` Viresh Kumar
2019-01-24 10:34 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Viresh Kumar @ 2019-01-08 5:00 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: Rafael J. Wysocki, linux-pm, linux-kernel
On 07-01-19, 11:33, 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/cpufreq/e_powersaver.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c
> index 60bea302abbe..2d3ef208dd70 100644
> --- a/drivers/cpufreq/e_powersaver.c
> +++ b/drivers/cpufreq/e_powersaver.c
> @@ -323,9 +323,8 @@ static int eps_cpu_init(struct cpufreq_policy *policy)
> states = 2;
>
> /* Allocate private data and frequency table for current cpu */
> - centaur = kzalloc(sizeof(*centaur)
> - + (states + 1) * sizeof(struct cpufreq_frequency_table),
> - GFP_KERNEL);
> + centaur = kzalloc(struct_size(centaur, freq_table, states + 1),
> + GFP_KERNEL);
> if (!centaur)
> return -ENOMEM;
> eps_cpu[0] = centaur;
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
--
viresh
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc()
2019-01-08 5:00 ` Viresh Kumar
@ 2019-01-24 10:34 ` Rafael J. Wysocki
2019-01-24 17:33 ` Gustavo A. R. Silva
0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2019-01-24 10:34 UTC (permalink / raw)
To: Viresh Kumar, Gustavo A. R. Silva; +Cc: linux-pm, linux-kernel
On Tuesday, January 8, 2019 6:00:56 AM CET Viresh Kumar wrote:
> On 07-01-19, 11:33, 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/cpufreq/e_powersaver.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c
> > index 60bea302abbe..2d3ef208dd70 100644
> > --- a/drivers/cpufreq/e_powersaver.c
> > +++ b/drivers/cpufreq/e_powersaver.c
> > @@ -323,9 +323,8 @@ static int eps_cpu_init(struct cpufreq_policy *policy)
> > states = 2;
> >
> > /* Allocate private data and frequency table for current cpu */
> > - centaur = kzalloc(sizeof(*centaur)
> > - + (states + 1) * sizeof(struct cpufreq_frequency_table),
> > - GFP_KERNEL);
> > + centaur = kzalloc(struct_size(centaur, freq_table, states + 1),
> > + GFP_KERNEL);
> > if (!centaur)
> > return -ENOMEM;
> > eps_cpu[0] = centaur;
>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Patch applied, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc()
2019-01-24 10:34 ` Rafael J. Wysocki
@ 2019-01-24 17:33 ` Gustavo A. R. Silva
0 siblings, 0 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-24 17:33 UTC (permalink / raw)
To: Rafael J. Wysocki, Viresh Kumar; +Cc: linux-pm, linux-kernel
On 1/24/19 4:34 AM, Rafael J. Wysocki wrote:
> On Tuesday, January 8, 2019 6:00:56 AM CET Viresh Kumar wrote:
>> On 07-01-19, 11:33, 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/cpufreq/e_powersaver.c | 5 ++---
>>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c
>>> index 60bea302abbe..2d3ef208dd70 100644
>>> --- a/drivers/cpufreq/e_powersaver.c
>>> +++ b/drivers/cpufreq/e_powersaver.c
>>> @@ -323,9 +323,8 @@ static int eps_cpu_init(struct cpufreq_policy *policy)
>>> states = 2;
>>>
>>> /* Allocate private data and frequency table for current cpu */
>>> - centaur = kzalloc(sizeof(*centaur)
>>> - + (states + 1) * sizeof(struct cpufreq_frequency_table),
>>> - GFP_KERNEL);
>>> + centaur = kzalloc(struct_size(centaur, freq_table, states + 1),
>>> + GFP_KERNEL);
>>> if (!centaur)
>>> return -ENOMEM;
>>> eps_cpu[0] = centaur;
>>
>> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> Patch applied, thanks!
>
Thank you both, Viresh and Rafael.
--
Gustavo
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-01-07 17:33 [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc() Gustavo A. R. Silva
2019-01-08 5:00 ` Viresh Kumar
2019-01-24 10:34 ` Rafael J. Wysocki
2019-01-24 17:33 ` Gustavo A. R. Silva
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