diff options
| author | David Howells <dhowells@redhat.com> | 2011-07-27 21:47:03 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-27 12:50:45 -0700 |
| commit | 09570f914914d2beb0db29c5a9c7344934f2fa8c (patch) | |
| tree | a93900db5e607887aca3ef2cecc2426abe007d87 /fs/proc | |
| parent | 5fd00b031530cc476240f654c078c930f1dcd6ea (diff) | |
| download | lwn-09570f914914d2beb0db29c5a9c7344934f2fa8c.tar.gz lwn-09570f914914d2beb0db29c5a9c7344934f2fa8c.zip | |
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>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/generic.c | 3 | ||||
| -rw-r--r-- | fs/proc/proc_net.c | 4 | ||||
| -rw-r--r-- | fs/proc/root.c | 2 |
3 files changed, 4 insertions, 5 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index f1637f17c37c..9d99131d0d65 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -620,8 +620,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, 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 9020ac15baaa..f738024ccc8e 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); diff --git a/fs/proc/root.c b/fs/proc/root.c index d6c3b416529b..9a8a2b77b874 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -186,13 +186,13 @@ static const struct inode_operations proc_root_inode_operations = { 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) |