| Message ID | 1296707648-28191-1-git-send-email-tamura.yoshiaki@lab.ntt.co.jp |
|---|---|
| State | New |
| Headers | show |
Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp> wrote: > Although it's rare to happen in live migration, when the head of a > byte stream contains 0x05 which is the marker of subsection, the > loader gets corrupted because vmstate_subsection_load() continues even > the device doesn't require it. This patch adds a checker whether > subsection is needed, and skips following routines if not needed. This only fixes "partially" the problem :( I agree with bonzini that it is better than what we had until we get the time to try a better aproach. I was thinking about only allowing subsections at the top level, but that still don't improve things, would have to think more about the problem. Reviewed-by: Juan Quintela <quintela@redhat.com> > Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp> > Acked-by: Paolo Bonzini <pbonzini@redhat.com> > --- > savevm.c | 10 +++++++++- > 1 files changed, 9 insertions(+), 1 deletions(-) > > diff --git a/savevm.c b/savevm.c > index 4453217..6d83b0f 100644 > --- a/savevm.c > +++ b/savevm.c > @@ -1638,6 +1638,12 @@ static const VMStateDescription *vmstate_get_subsection(const VMStateSubsection > static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, > void *opaque) > { > + const VMStateSubsection *sub = vmsd->subsections; > + > + if (!sub || !sub->needed) { > + return 0; > + } > + > while (qemu_peek_byte(f) == QEMU_VM_SUBSECTION) { > char idstr[256]; > int ret; > @@ -1650,10 +1656,11 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, > idstr[len] = 0; > version_id = qemu_get_be32(f); > > - sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr); > + sub_vmsd = vmstate_get_subsection(sub, idstr); > if (sub_vmsd == NULL) { > return -ENOENT; > } > + assert(!sub_vmsd->subsections); > ret = vmstate_load_state(f, sub_vmsd, opaque, version_id); > if (ret) { > return ret; > @@ -1677,6 +1684,7 @@ static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, > qemu_put_byte(f, len); > qemu_put_buffer(f, (uint8_t *)vmsd->name, len); > qemu_put_be32(f, vmsd->version_id); > + assert(!vmsd->subsections); > vmstate_save_state(f, vmsd, opaque); > } > sub++;
On 02/02/2011 10:34 PM, Yoshiaki Tamura wrote: > Although it's rare to happen in live migration, when the head of a > byte stream contains 0x05 which is the marker of subsection, the > loader gets corrupted because vmstate_subsection_load() continues even > the device doesn't require it. This patch adds a checker whether > subsection is needed, and skips following routines if not needed. > > Signed-off-by: Yoshiaki Tamura<tamura.yoshiaki@lab.ntt.co.jp> > Acked-by: Paolo Bonzini<pbonzini@redhat.com> > Applied to master, Thanks. Regards, Anthony Liguori > --- > savevm.c | 10 +++++++++- > 1 files changed, 9 insertions(+), 1 deletions(-) > > diff --git a/savevm.c b/savevm.c > index 4453217..6d83b0f 100644 > --- a/savevm.c > +++ b/savevm.c > @@ -1638,6 +1638,12 @@ static const VMStateDescription *vmstate_get_subsection(const VMStateSubsection > static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, > void *opaque) > { > + const VMStateSubsection *sub = vmsd->subsections; > + > + if (!sub || !sub->needed) { > + return 0; > + } > + > while (qemu_peek_byte(f) == QEMU_VM_SUBSECTION) { > char idstr[256]; > int ret; > @@ -1650,10 +1656,11 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, > idstr[len] = 0; > version_id = qemu_get_be32(f); > > - sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr); > + sub_vmsd = vmstate_get_subsection(sub, idstr); > if (sub_vmsd == NULL) { > return -ENOENT; > } > + assert(!sub_vmsd->subsections); > ret = vmstate_load_state(f, sub_vmsd, opaque, version_id); > if (ret) { > return ret; > @@ -1677,6 +1684,7 @@ static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, > qemu_put_byte(f, len); > qemu_put_buffer(f, (uint8_t *)vmsd->name, len); > qemu_put_be32(f, vmsd->version_id); > + assert(!vmsd->subsections); > vmstate_save_state(f, vmsd, opaque); > } > sub++; >
diff --git a/savevm.c b/savevm.c index 4453217..6d83b0f 100644 --- a/savevm.c +++ b/savevm.c @@ -1638,6 +1638,12 @@ static const VMStateDescription *vmstate_get_subsection(const VMStateSubsection static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, void *opaque) { + const VMStateSubsection *sub = vmsd->subsections; + + if (!sub || !sub->needed) { + return 0; + } + while (qemu_peek_byte(f) == QEMU_VM_SUBSECTION) { char idstr[256]; int ret; @@ -1650,10 +1656,11 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, idstr[len] = 0; version_id = qemu_get_be32(f); - sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr); + sub_vmsd = vmstate_get_subsection(sub, idstr); if (sub_vmsd == NULL) { return -ENOENT; } + assert(!sub_vmsd->subsections); ret = vmstate_load_state(f, sub_vmsd, opaque, version_id); if (ret) { return ret; @@ -1677,6 +1684,7 @@ static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, qemu_put_byte(f, len); qemu_put_buffer(f, (uint8_t *)vmsd->name, len); qemu_put_be32(f, vmsd->version_id); + assert(!vmsd->subsections); vmstate_save_state(f, vmsd, opaque); } sub++;