| Message ID | 20190107173343.GA4258@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | cpufreq: e_powersaver: Use struct_size() in kzalloc() | expand |
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>
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!
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
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;
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(-)