| Message ID | 20190108161356.GA23617@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | sparc: use struct_size() in kzalloc() | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Tue, 8 Jan 2019 10:13:56 -0600 > 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> Applied.
Hi Dave, I wonder if you can take this. Thanks -- Gustavo On 1/8/19 10:13 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> > --- > arch/sparc/kernel/cpumap.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/sparc/kernel/cpumap.c b/arch/sparc/kernel/cpumap.c > index d1d52822603d..1cb62bfeaa1f 100644 > --- a/arch/sparc/kernel/cpumap.c > +++ b/arch/sparc/kernel/cpumap.c > @@ -194,8 +194,7 @@ static struct cpuinfo_tree *build_cpuinfo_tree(void) > > n = enumerate_cpuinfo_nodes(tmp_level); > > - new_tree = kzalloc(sizeof(struct cpuinfo_tree) + > - (sizeof(struct cpuinfo_node) * n), GFP_ATOMIC); > + new_tree = kzalloc(struct_size(new_tree, nodes, n), GFP_ATOMIC); > if (!new_tree) > return NULL; > >
diff --git a/arch/sparc/kernel/cpumap.c b/arch/sparc/kernel/cpumap.c index d1d52822603d..1cb62bfeaa1f 100644 --- a/arch/sparc/kernel/cpumap.c +++ b/arch/sparc/kernel/cpumap.c @@ -194,8 +194,7 @@ static struct cpuinfo_tree *build_cpuinfo_tree(void) n = enumerate_cpuinfo_nodes(tmp_level); - new_tree = kzalloc(sizeof(struct cpuinfo_tree) + - (sizeof(struct cpuinfo_node) * n), GFP_ATOMIC); + new_tree = kzalloc(struct_size(new_tree, nodes, n), GFP_ATOMIC); if (!new_tree) return NULL;
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> --- arch/sparc/kernel/cpumap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)