[BusyBox 0003074]: "mount -o bind ..." returns invalid argumnent for elements in /dev folder

[bugs at busybox.net]

The following issue has been SUBMITTED. 
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http://busybox.net/bugs/view.php?id=3074 
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Reported By:                addu219
Assigned To:                BusyBox
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Project:                    BusyBox
Issue ID:                   3074
Category:                   Kernel Module Support
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
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Date Submitted:             04-22-2008 15:18 PDT
Last Modified:              04-22-2008 15:18 PDT
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Summary:                    "mount  -o bind  ..." returns invalid argumnent for
elements in /dev folder
Description: 
I am using the busybox 1.10.0

I am trying to mount an element log in /dev
srw-rw-rw-    1 root     root        0 Apr 22 17:27 log

For a trivial case I am trying to mount it onto  /tmp/log through the
command 
mount -t none -o bind /dev/log /tmp/log

I get the message "mount: mounting /dev/log on /tmp/log failed: Invalid
argument"

I have noticed this error message while mounting any element present in
the /dev directory.

The elements in the following folders get mounted successfully:
/home, /tmp, /var

e.g if I copy the element log into /var and try mounting it with the
command
mount -t none -o bind /var/log /tmp/log 
It is successful!!

I have played around with the folder permissions for /dev but to no
avail.

There are other folders in the root directory as well for which the mount
command returns the "invalid argument" error. Some of them are
/bin, /etc, /lib, /sbin, /usr

I just want to know the reason as to why can't elements in /dev and other
folders listed above, be mounted. Is there some restriction due the -o
bind option that it does not accept elements in these folder as a valid
argument.

Let me know what could be wrong.
Thanks

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Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
04-22-08 15:18  addu219        New Issue                                    
04-22-08 15:18  addu219        Status                   new => assigned     
04-22-08 15:18  addu219        Assigned To               => BusyBox         
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