[PATCH] security: selinux: use kmem_cache for ebitmap

On Tue, Jun 6, 2017 at 7:38 PM, ???/???/MC??? BSP?
BSP6?(junil0814.lee at lge.com) [off-list ref] wrote:

Paul Moore wrote on 2017-06-06 ?? 6:39:

quoted

On Mon, Jun 5, 2017 at 5:10 AM, Junil Lee [off-list ref] wrote:

quoted

The allocated size for each ebitmap_node is 192byte by kzalloc().
Then, ebitmap_node size is fixed, so it's possible to use only 144byte
for each object by kmem_cache_zalloc().
It can reduce some dynamic allocation size.

Signed-off-by: Junil Lee <redacted>
---
security/selinux/ss/ebitmap.c | 24 +++++++++++++++++++-----
security/selinux/ss/ebitmap.h | 3 +++
security/selinux/ss/services.c | 4 ++++
3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/security/selinux/ss/ebitmap.c

b/security/selinux/ss/ebitmap.c

quoted

index 9db4709a..076c96f 100644

--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c

@@ -24,6 +24,8 @@

#define BITS_PER_U64 (sizeof(u64) * 8)

+static struct kmem_cache *ebitmap_node_cachep;
+
int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
{
struct ebitmap_node *n1, *n2;

@@ -54,7 +56,7 @@ int ebitmap_cpy(struct ebitmap *dst, struct ebitmap

*src)

quoted

n = src->node;
prev = NULL;
while (n) {
- new = kzalloc(sizeof(*new), GFP_ATOMIC);
+ new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
if (!new) {
ebitmap_destroy(dst);
return -ENOMEM;

@@ -162,7 +164,7 @@ int ebitmap_netlbl_import(struct ebitmap *ebmap,

if (e_iter == NULL ||
offset >= e_iter->startbit + EBITMAP_SIZE) {
e_prev = e_iter;
- e_iter = kzalloc(sizeof(*e_iter), GFP_ATOMIC);
+ e_iter = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
if (e_iter == NULL)
goto netlbl_import_failure;
e_iter->startbit = offset - (offset % EBITMAP_SIZE);

@@ -299,7 +301,7 @@ int ebitmap_set_bit(struct ebitmap *e, unsigned

long bit, int value)

quoted

if (!value)
return 0;

- new = kzalloc(sizeof(*new), GFP_ATOMIC);
+ new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
if (!new)
return -ENOMEM;

I believe there is a kfree() in ebitmap_set_bit() that also needs to
be converted.

Thanks for your advice Paul.
reattach patch v2.

Please submit patches inline, just as you did for your original
posting.  It make it easier to review and apply.

Thanks.

-- 
paul moore
www.paul-moore.com
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html