Re: [PATCH v3] hw/arm: do not free machine->fdt in arm_load_dtb()

[Daniel Henrique Barboza]

On 3/30/23 08:58, Alexander Bulekov wrote:
> On 230328 1859, Markus Armbruster wrote:
> > At this moment, arm_load_dtb() can free machine->fdt when
> > binfo->dtb_filename is NULL. If there's no 'dtb_filename', 'fdt' will be
> > retrieved by binfo->get_dtb(). If get_dtb() returns machine->fdt, as is
> > the case of machvirt_dtb() from hw/arm/virt.c, fdt now has a pointer to
> > machine->fdt. And, in that case, the existing g_free(fdt) at the end of
> > arm_load_dtb() will make machine->fdt point to an invalid memory region.
> >
> > Since monitor command 'dumpdtb' was introduced a couple of releases
> > ago, running it with any ARM machine that uses arm_load_dtb() will
> > crash QEMU.
> >
> > Let's enable all arm_load_dtb() callers to use dumpdtb properly. Instead
> > of freeing 'fdt', assign it back to ms->fdt.
> >
> > Cc: Peter Maydell <peter.maydell@linaro.org>
> > Cc: qemu-arm@nongnu.org
> > Fixes: bf353ad55590f ("qmp/hmp, device_tree.c: introduce dumpdtb")
> > Reported-by: Markus Armbruster <armbru@redhat.com>i
>                                                      ^ Seems like a typo
>
>                                                      -Alex

Yeah it is. Persisted ever since v2 :D

Nice catch!


Daniel