| Message ID | 1435611725-15161-4-git-send-email-konrad.wilk@oracle.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 29 Jun 2015, Konrad Rzeszutek Wilk wrote: > It should never happen, but in case it does we want to > report. The code will only write up to reg->size so there > is no runtime danger. > > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > hw/xen/xen_pt_config_init.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c > index 91c3a14..bc871c9 100644 > --- a/hw/xen/xen_pt_config_init.c > +++ b/hw/xen/xen_pt_config_init.c > @@ -1901,9 +1901,13 @@ static int xen_pt_config_reg_init(XenPCIPassthroughState *s, > } else > val = data; > > + if (val & size_mask) { > + XEN_PT_ERR(&s->dev,"Offset 0x%04x:0x%04u expands past register size(%d)!\n", > + offset, val, reg->size); should we return early? > + } > /* This could be just pci_set_long as we don't modify the bits > - * past reg->size, but in case this routine is run in parallel > - * we do not want to over-write other registers. */ > + * past reg->size, but in case this routine is run in parallel or the > + * init value is larger, we do not want to over-write registers. */ > switch (reg->size) { > case 1: pci_set_byte(s->dev.config + offset, (uint8_t)val); break; > case 2: pci_set_word(s->dev.config + offset, (uint16_t)val); break; > -- > 2.1.0 >
diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c index 91c3a14..bc871c9 100644 --- a/hw/xen/xen_pt_config_init.c +++ b/hw/xen/xen_pt_config_init.c @@ -1901,9 +1901,13 @@ static int xen_pt_config_reg_init(XenPCIPassthroughState *s, } else val = data; + if (val & size_mask) { + XEN_PT_ERR(&s->dev,"Offset 0x%04x:0x%04u expands past register size(%d)!\n", + offset, val, reg->size); + } /* This could be just pci_set_long as we don't modify the bits - * past reg->size, but in case this routine is run in parallel - * we do not want to over-write other registers. */ + * past reg->size, but in case this routine is run in parallel or the + * init value is larger, we do not want to over-write registers. */ switch (reg->size) { case 1: pci_set_byte(s->dev.config + offset, (uint8_t)val); break; case 2: pci_set_word(s->dev.config + offset, (uint16_t)val); break;
It should never happen, but in case it does we want to report. The code will only write up to reg->size so there is no runtime danger. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- hw/xen/xen_pt_config_init.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)