[PATCH 2/5] kernfs: convert node name allocation to kstrdup_const

Andrzej Hajda
2015-01-12T09:20:10Z

sysfs frequently performs duplication of strings located
in read-only memory section. Replacing kstrdup by kstrdup_const
allows to avoid such operations.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
---
fs/kernfs/dir.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 37989f0..259e92a 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -408,7 +408,7 @@ void kernfs_put(struct kernfs_node *kn)
if (kernfs_type(kn) == KERNFS_LINK)
kernfs_put(kn->symlink.target_kn);
if (!(kn->flags & KERNFS_STATIC_NAME))
- kfree(kn->name);
+ kfree_const(kn->name);
if (kn->iattr) {
if (kn->iattr->ia_secdata)
security_release_secctx(kn->iattr->ia_secdata,
@@ -502,12 +502,12 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
const char *name, umode_t mode,
unsigned flags)
{
- char *dup_name = NULL;
+ const char *dup_name = NULL;
struct kernfs_node *kn;
int ret;

if (!(flags & KERNFS_STATIC_NAME)) {
- name = dup_name = kstrdup(name, GFP_KERNEL);
+ name = dup_name = kstrdup_const(name, GFP_KERNEL);
if (!name)
return NULL;
}
@@ -534,7 +534,7 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
err_out2:
kmem_cache_free(kernfs_node_cache, kn);
err_out1:
- kfree(dup_name);
+ kfree_const(dup_name);
return NULL;
}

@@ -1260,7 +1260,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
/* rename kernfs_node */
if (strcmp(kn->name, new_name) != 0) {
error = -ENOMEM;
- new_name = kstrdup(new_name, GFP_KERNEL);
+ new_name = kstrdup_const(new_name, GFP_KERNEL);
if (!new_name)
goto out;
} else {
@@ -1293,7 +1293,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
kernfs_link_sibling(kn);

kernfs_put(old_parent);
- kfree(old_name);
+ kfree_const(old_name);

error = 0;
out:
--
1.9.1