Hi, Dave, I will check the code about vmstate_spapr_tce_table to figure out the problem of seg fault. Thank you for your check.
Jinhao Gao -----Original Message----- From: Dr. David Alan Gilbert [mailto:dgilb...@redhat.com] Sent: 2021年2月8日 18:53 To: gaojinhao <gaojin...@huawei.com> Cc: qemu-...@nongnu.org; qemu-devel@nongnu.org; Michael S . Tsirkin <m...@redhat.com>; David Gibson <da...@gibson.dropbear.id.au>; Greg Kurz <gr...@kaod.org>; Marc-André Lureau <marcandre.lur...@redhat.com>; Stefan Berger <stef...@linux.vnet.ibm.com>; Jason Wang <jasow...@redhat.com>; Juan Quintela <quint...@redhat.com>; Wanghaibin (D) <wanghaibin.w...@huawei.com>; zhukeqian <zhukeqi...@huawei.com> Subject: Re: [PATCH v3 3/3] vmstate: Fix memory leak in vmstate_handle_alloc() * Dr. David Alan Gilbert (dgilb...@redhat.com) wrote: > * Jinhao Gao (gaojin...@huawei.com) wrote: > > Some memory allocated for fields having a flag of VMS_ALLOC in > > SaveState may not free before VM load vmsd in migration. So we > > pre-free memory before allocation in vmstate_handle_alloc() to avoid > > memleaks. > > > > Reported-by: Euler Robot <euler.ro...@huawei.com> > > Signed-off-by: Jinhao Gao <gaojin...@huawei.com> > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > > Yes, I think that's OK; it's actually pretty rare for this to happen; > normally inwards migrations either succeed or fail and exit; doing > multiple loads from snapshots is valid and I guess COLO hits this as well. > > Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> I'm having to unqueue this because it's triggering a seg fault on Power in iotest 267 (just run make check). #2 0x0000000116d0d4c8 in vmstate_handle_alloc (opaque=<optimized out>, field=0x11799e0c8 <__compound_literal.1+312>, ptr=0x1001f8f14b0) at ../qemu/migration/vmstate.c:73 #3 0x0000000116d0d4c8 in vmstate_load_state (f=0x1001f6d0000, vmsd=0x117928730 <vmstate_spapr_tce_table>, opaque=0x1001f8f1400, version_id=<optimized out>) at ../qemu/migration/vmstate.c:122 #4 0x0000000116fb4a4c in vmstate_load (f=0x1001f6d0000, se=0x1001fc7bc40) at ../qemu/migration/savevm.c:910 #5 0x0000000116fb5010 in qemu_loadvm_section_start_full (f=f@entry=0x1001f6d0000, mis=<optimized out>) at ../qemu/migration/savevm.c:2433 It's the mig_nb_table that Power is doing some special handling with; so it needs some more checking before we can fix this. Dave > > --- > > migration/vmstate.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/migration/vmstate.c b/migration/vmstate.c index > > e9d2aef66b..873f76739f 100644 > > --- a/migration/vmstate.c > > +++ b/migration/vmstate.c > > @@ -70,6 +70,7 @@ static void vmstate_handle_alloc(void *ptr, const > > VMStateField *field, > > gsize size = vmstate_size(opaque, field); > > size *= vmstate_n_elems(opaque, field); > > if (size) { > > + g_free(*(void **)ptr); > > *(void **)ptr = g_malloc(size); > > } > > } > > -- > > 2.23.0 > > > -- > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
