proc: make struct proc_dir_entry::name a terminal array rather than a pointer

Since __proc_create() appends the name it is given to the end of the PDE
structure that it allocates, there isn't a need to store a name pointer.
Instead we can just replace the name pointer with a terminal char array of
_unspecified_ length.  The compiler will simply append the string to statically
defined variables of PDE type overlapping any hole at the end of the structure
and, unlike specifying an explicitly _zero_ length array, won't give a warning
if you try to statically initialise it with a string of more than zero length.

Also, whilst we're at it:

 (1) Move namelen to end just prior to name and reduce it to a single byte
     (name shouldn't be longer than NAME_MAX).

 (2) Move pde_unload_lock two places further on so that if it's four bytes in
     size on a 64-bit machine, it won't cause an unused hole in the PDE struct.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index 9020ac1..f738024 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -197,15 +197,15 @@ static __net_init int proc_net_ns_init(struct net *net)
 	int err;
 
 	err = -ENOMEM;
-	netd = kzalloc(sizeof(*netd), GFP_KERNEL);
+	netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
 	if (!netd)
 		goto out;
 
 	netd->data = net;
 	netd->nlink = 2;
-	netd->name = "net";
 	netd->namelen = 3;
 	netd->parent = &proc_root;
+	memcpy(netd->name, "net", 4);
 
 	err = -EEXIST;
 	net_statd = proc_net_mkdir(net, "stat", netd);