Re: [uml-devel] [patch] mconsole_proc rewrite (and crash fix).

[Gerd Knorr <kraxel@bytesex.org>]

On Wed, Aug 11, 2004 at 07:57:40PM +0200, BlaisorBlade wrote:
        ^^^^^^
Did the mail really travel that long, or is your clock broken?

> Actually the exec command cannot send anything to the mconsole, but since it 
> invokes sh -c it allows for redirections to new consoles.

Having the output go directly to mconsole is much easier to handle
through.

> > The old code had the problem that the kernel crashed after calling
> > "uml_mconsole proc <somefile>" a few times.  I havn't tracked what
> > exactly causes the problem, I guess trying to access the procfs without
> > actually mounting it somewhere causes some corruption of kernel data
> > structures.
> 
> Who said that he didn't have mounted /proc inside the guest?

Code looks like that, as it uses get_filesystem and all that instead of
doing a simple /proc/... path lookup.  What is the point of doing it
that way, other than make it work even if procfs is not mounted below
/proc?

> However, I see basically two bugs:
> 1) why put_filesystem is not called at the end?

It is called earlier, right after ->get_sb() call.  Which looks sane to
me, as a successfull get_sb() should increase the refcount and thus
releasing the filesystems afterwards should be safe.  I'm no VFS expert
through.

  Gerd

-- 
return -ENOSIG;


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