* Peter Maydell (peter.mayd...@linaro.org) wrote: > On 10 January 2017 at 09:26, Dr. David Alan Gilbert <dgilb...@redhat.com> > wrote: > > * Peter Maydell (peter.mayd...@linaro.org) wrote: > >> On 9 January 2017 at 20:13, Dr. David Alan Gilbert (git) > >> <dgilb...@redhat.com> wrote: > >> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > >> > > >> > Check qdev's call to vmstate_register_with_alias_id; that gets > >> > most of the common uses; there's hundreds of calls via vmstate_register > >> > which could get fixed over time. > >> > >> Not quite that bad, I think -- I make it just over 50 calls. > > > > Well kind of; it seems to be a bit more complicated than that. > > I'd grep'd for vmstate_register and that gives me ~180 (including > > stuff in headers). > > Yes, I was specifically looking at the vmstate_register and > vmstate_register_with_alias_id ones. > > > Only 56 of those are vmstate_register() calls though, 117 are > > vmstate_register_ram calls which I'd not previously looked at, > > those call qemu_ram_set_idstr which looks like it suffers from > > the same problem though. > > They call qemu_ram_set_idstr with the memory region name string, > though, which is "used for debugging; not visible to the user > or ABI", so we can just say it's a bug to use a silly name > and assert if it's too big, right?
qemu_ram_set_idstr already abort's if it hits a dupe (which after making sure it doesn't overflow the buffer is what we end up with if we have long names); so yes we already abort in that case. However, it's a bit optimistic of the memory region to claim the name is just for debug; Migration/ram.c transmits the RAMBlock's idstr on the wire (as does postcopy) - so I think the memory.h comment is wrong. I don't think it's a big problem since you're unlikely to hit these big names in practice; but it would be better to return an error rather than assert/abort since then you wouldn't abort as part of a hot-add. So it's worth taking the common cases as this patch does; I don't think it's worth the hastle of changing 100+ calls though. Dave > thanks > -- PMM -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
