Re: [Qemu-devel] [PATCH 3/3] async: Allow nested qemu_bh_poll calls

[Stefan Hajnoczi]

On Thu, Sep 1, 2011 at 3:31 PM, Kevin Wolf <address@hidden> wrote:
> qemu may segfault when a BH handler first deletes a BH and then (possibly
> indirectly) calls a nested qemu_bh_poll(). This is because the inner instance
> frees the BH and deletes it from the list that the outer one processes.
>
> This patch deletes BHs only in the outermost qemu_bh_poll instance.
>
> Commit 7887f620 already tried to achieve the same, but it assumed that the BH
> handler would only delete its own BH. With a nested qemu_bh_poll(), this isn't
> guaranteed, so that commit wasn't enough. Hope this one fixes it for real.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  async.c |   24 ++++++++++++++++--------
>  1 files changed, 16 insertions(+), 8 deletions(-)

Seems okay as a fix.

Stefan