Re: Kernel-Crash when working with ubt0

From: <mms.vanbreukelingen_at_gmail.com>
Date: Wed, 28 Aug 2019 22:34:21 +0000 (UTC)
_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

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 - 20:34:26 UTC

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