Re: /proc parent &proc_root == NULL?

["Randy.Dunlap" <rddunlap@osdl.org>]

John Richard Moser wrote:
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> proc_misc_init() has both these lines in it:
> 
> entry = create_proc_entry("kmsg", S_IRUSR, &proc_root);
> proc_root_kcore = create_proc_entry("kcore", S_IRUSR, NULL);
> 
> Both entries show up in /proc, as /proc/kmsg and /proc/kcore.  So I ask,
> as I can't see after several minutes of examination, what's the
> difference?  Why is NULL used for some and &proc_root used for others?
> 
> I'm looking at 2.6.10

create_proc_entry() passes &parent to proc_create().
See proc_create():
...
This is an error path:
	if (!(*parent) && xlate_proc_name(name, parent, &fn) != 0)
		goto out;
but xlate_proc_name() searches for a /proc/.... and returns the 
all-but-final-part-of-name *parent (hope that makes some sense,
see the comments above the function), so it returns &proc_root.

HTH.  If not, fire back.
-- 
~Randy