O_CAREFUL flag to disable open() side effects

[H. Peter Anvin]

Alan Cox wrote:
> Ar Iau, 2006-07-27 am 20:05 +0300, ysgrifennodd Pekka J Enberg:
> > Sure. Though I wonder if sys_frevoke is enough for us and we can drop 
> > sys_revoke completely.
>
> Alas not. Some Unix devices have side effects when you open() them. 

Dumb thought: would it make sense to add an O_CAREFUL flag to open(), to 
disable side effects?  It seems that a number of devices have this issue 
and one have to jump through weird hoops to configure them.  Obviously, 
a file descriptor obtained with O_CAREFUL may not be fully functional, 
at the device driver's option.

For a conventional file, directory, or block device O_CAREFUL is a 
no-op.  For ttys it would typically behave similar to O_NONBLOCK 
followed immediately by a fcntl to clear the nonblock flag.

	-hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/