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>
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index f1637f1..9d99131 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -620,8 +620,7 @@
if (!ent) goto out;
memset(ent, 0, sizeof(struct proc_dir_entry));
- memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1);
- ent->name = ((char *) ent) + sizeof(*ent);
+ memcpy(ent->name, fn, len + 1);
ent->namelen = len;
ent->mode = mode;
ent->nlink = nlink;
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 @@
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);
diff --git a/fs/proc/root.c b/fs/proc/root.c
index d6c3b41..9a8a2b7 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -186,13 +186,13 @@
struct proc_dir_entry proc_root = {
.low_ino = PROC_ROOT_INO,
.namelen = 5,
- .name = "/proc",
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
.nlink = 2,
.count = ATOMIC_INIT(1),
.proc_iops = &proc_root_inode_operations,
.proc_fops = &proc_root_operations,
.parent = &proc_root,
+ .name = "/proc",
};
int pid_ns_prepare_proc(struct pid_namespace *ns)