[PATCH] tracefs: Simplify get_dname() with kmemdup_nul()

[AnishMulay]

In fs/tracefs/inode.c, get_dname() allocates a buffer with kmalloc()
to hold a dentry name, followed by a memcpy() and manual
null-termination.

Replace this open-coded pattern with the standard kmemdup_nul() helper.
Additionally, remove the now single-use local variables `dname` and
`len`. This simplifies the function to a single line, reducing visual
clutter and making the memory-safety intent immediately obvious without
changing any functional behavior.

Testing:
Booted a custom kernel natively in virtme-ng (ARM64). Triggered tracefs
inode and dentry allocation by creating and removing a custom directory
under a temporary tracefs mount. Verified that the instance is created
successfully and that no memory errors or warnings are emitted in dmesg.

Signed-off-by: AnishMulay <anishm7030@xxxxxxxxx>
---
 fs/tracefs/inode.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index d9d8932a7b9c9..86ba8dc25aaef 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -96,17 +96,7 @@ static struct tracefs_dir_ops {
 
 static char *get_dname(struct dentry *dentry)
 {
-	const char *dname;
-	char *name;
-	int len = dentry->d_name.len;
-
-	dname = dentry->d_name.name;
-	name = kmalloc(len + 1, GFP_KERNEL);
-	if (!name)
-		return NULL;
-	memcpy(name, dname, len);
-	name[len] = 0;
-	return name;
+	return kmemdup_nul(dentry->d_name.name, dentry->d_name.len, GFP_KERNEL);
 }
 
 static struct dentry *tracefs_syscall_mkdir(struct mnt_idmap *idmap,
-- 
2.51.0