[libvirt] [PATCH v5 06/36] qemu_capabilities: Stop QEMU process before freeing

[Jiri Denemark]

On Sun, Dec 02, 2018 at 23:10:00 -0600, Chris Venteicher wrote:
> virQEMUCapsInitQMP now stops QEMU process in all execution paths,
> before freeing the process structure.
> 
> The qemuProcessQmpStop function can be called multiple times without
> problems... Won't attempt to stop processes and free resources multiple
> times.
> 
> Follow the convention established in qemu_process of
> 1) alloc process structure
> 2) start process
> 3) use process
> 4) stop process
> 5) free process data structure
> 
> The process data structure persists after the process activation fails
> or the process dies or is killed so stderr strings can be retrieved
> until the process data structure is freed.
> 
> Signed-off-by: Chris Venteicher <cventeic at redhat.com>
> ---
>  src/qemu/qemu_capabilities.c |  1 +
>  src/qemu/qemu_process.c      | 19 ++++++++++++-------
>  2 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> index d903fbddf8..a79329a134 100644
> --- a/src/qemu/qemu_capabilities.c
> +++ b/src/qemu/qemu_capabilities.c
> @@ -4273,6 +4273,7 @@ virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps,
>      ret = 0;
>  
>   cleanup:
> +    qemuProcessQmpStop(proc);

This would still crash libvirt if qemuProcessQmpNew() failed.

>      qemuProcessQmpFree(proc);
>      return ret;
>  }
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index 8465448a49..fa050a1a27 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -8263,14 +8263,17 @@ qemuProcessQmpRun(qemuProcessQmpPtr proc,
>  void
>  qemuProcessQmpStop(qemuProcessQmpPtr proc)
>  {

Here you'd need to add

        if (!proc)
            return;

> -    if (proc->mon)
> +    if (proc->mon) {
>          virObjectUnlock(proc->mon);
...

And obviously s/Qmp/QMP/g.

Jirka