Re: EXPORT_SYMBOL for chrdev_open 2.4.3

From: Jeff V. Merkey (jmerkey@vger.timpanogas.org)
Date: Fri Apr 13 2001 - 20:35:57 EST


On Fri, Apr 13, 2001 at 09:25:10PM -0400, Alexander Viro wrote:
>
>
> On Fri, 13 Apr 2001, Jeff V. Merkey wrote:
>
> > Not meaning to offend, but how could you know what everyone
> > who uses Linux needs in every instance? NT, NetWare, etc. all
> > expose these types of APIs for Backup and anti-virus software,
> > etc. The APIs in question are the very calls user space apps
> > call through the syscall to indicate who is using a device.
>
> Backup and AV software is not in the kernel, so they would
> be unable to use the thing, exported or not. Please, don't
> bring the strawmen.

Some NT anti-virus stuff is in-kernel, and it's there to catch people
writing viruses that act like device drivers. One day, if and
when a Linux virus shows it's ugly head disguised as a kernel module, you
will be backpeddling on this statement, and wishing we had in
kernel anti-virus support. In W2K, folks have written some
clever viruses that plug into their kernel as bogus device
drivers.

>
> Novell's model (aka. "we don't need no stinkin' userland, everything
> is NLM and security be damned") is better left to rot in hell with Novell.

Well, I am working with them again, and they have taken quite a
beating at our hands (and I sure didn't do them any good putting out
the file system on Linux and free Migration tools). Saying the word "Linux"
around Novell definitely solicits a very worried and serious response.

I am trying to be nice to them -- Linux is eroding their installed
base at light speed at this point. I'm sorry to say they show
absolutely **NO** interest in doing things to promote Linux to
their installed base in anyway that could benefit either them
or Linux.

>
> > Sure, I can send blind I/O requests to a device and I guess
> > someone running fdisk in user space can blow the device away from beneath
> > me since I have no way of locking those partitions I exclusively
> > own and stopping this is these apis are removed and modules
> > cannot call them.
>
> Use filp_open() - it's that simple.

Thanks. This is what I needed to know. I saw filp_open() in the
EXPORTS file, but was uncertain if this would be an unchanging API.
You have clarified this.

I will convert my code to use this call instead. Linus, if Al wants
the APIs removed from the export list, it sounds like filp_open()
will handle future issues relative to my requirements, so I have
no objection to them being removed.

I'll let Al know if there are any problems with using them.

Al, Thanks for the info.

:-)

Jeff

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



This archive was generated by hypermail 2b29 : Sun Apr 15 2001 - 21:00:22 EST