Re: Kernel-Crash when working with ubt0

From: Warner Losh <imp_at_bsdimp.com>
Date: Wed, 28 Aug 2019 19:48:06 -0600
On Wed, Aug 28, 2019, 4:34 PM mms.vanbreukelingen_at_gmail.com <
mms.vanbreukelingen_at_gmail.com> wrote:

> _at_Maksim, I first did a "git apply -R bt.diff" and then
>
> root_at_freeBSD13:/usr/src # git apply --stat --check --ignore-whitespace
> ng_btsocket_hci_raw.c.diff.txt
> error: patch failed:
> head/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c:1156
> error: head/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c: patch
> does not apply
>

patch -p1 worked for me to apply it.

And it worked just fine for everything once I rebooted. The patch looked
fine to my eye.

Warner


Rebuilding with MTX_SPIN=y (withouth patch)...
> On Wed, 28 Aug 2019 at 19:10, Maksim Yevmenkin <maksim.yevmenkin_at_gmail.com>
> wrote:
>
> > > > Hmm... interesting....
> > > >
> > > > I only took a brief look at it. I suppose I can ensure user space
> address is wired and then copyout() can be called with mutex held
> > >
> > > >No, you cannot do this, at least without making the kernel to panic.
> > > User might unmap the wired mapping at any time still.
> >
> > Kostik,
> >
> > i was thinking along the lines of vslock/vsunlock and copyout_nofault.
> > basically similar to the sysctl code. do you think this would not
> > work?
>
> actually, i dont think i need to hold lock over copyout. attached is
> my version of the patch (untested)
>
> thanks,
> max
>
>
Received on Wed Aug 28 2019 - 23:48:20 UTC

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