Subject: Re: [WTF?] sys_tas() on m32r
From: Lee Revell <rlrevell@joe-job.com>
To: Andrew Morton <akpm@osdl.org>
Cc: Al Viro <viro@ftp.linux.org.uk>, linux-kernel@vger.kernel.org,
       Hirokazu Takata <takata@linux-m32r.org>
In-Reply-To: <20051223055526.bc1a4044.akpm@osdl.org>
References: <20051223061556.GR27946@ftp.linux.org.uk>
	 <20051223055526.bc1a4044.akpm@osdl.org>
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Date: Fri, 23 Dec 2005 14:10:34 -0500
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On Fri, 2005-12-23 at 05:55 -0800, Andrew Morton wrote:
> Al Viro <viro@ftp.linux.org.uk> wrote:
> >
> > asmlinkage int sys_tas(int *addr)
> > {
> >         int oldval;
> >         unsigned long flags;
> > 
> >         if (!access_ok(VERIFY_WRITE, addr, sizeof (int)))
> >                 return -EFAULT;
> >         local_irq_save(flags);
> >         oldval = *addr;
> >         if (!oldval)
> >                 *addr = 1;
> >         local_irq_restore(flags);
> >         return oldval;
> > }
> > in arch/m32r/kernel/sys_m32r.c.  Trivial oops *AND* ability to trigger
> > IO with interrupts disabled.
> 
> Yeah.  I pointed this out to Takata in October last year and then promptly
> forgot about it.  It's rather amazing that this code (which appears to be in
> live use in linuxthreads) hasn't generated oopses.

No one uses LinuxThreads anymore?

Even the oldest of the old (Debian stable) have moved to NPTL.

Lee

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