Re: [PATCH-for-5.2 v2] hw/core/qdev-properties-system: Rewrite set_pci_host_devaddr using GLib

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Nov 20, 2020 at 12:00:56PM +0100, Philippe Mathieu-Daudé wrote:
> On 11/17/20 12:16 PM, Philippe Mathieu-Daudé wrote:
> > ping???
> > 
> > On 11/9/20 3:16 PM, Philippe Mathieu-Daudé wrote:
> >> Cc'ing PCI developers (rc2 is scheduled for tomorrow).
> >>
> >> On 11/7/20 9:59 AM, Philippe Mathieu-Daudé wrote:
> >>> Ping for 5.2 as this is a bugfix.
> >>>
> >>> On 10/13/20 12:22 PM, Philippe Mathieu-Daudé wrote:
> >>>> set_pci_host_devaddr() is hard to follow, thus bug-prone.
> >>>> We indeed introduced a bug in commit bccb20c49df, as the
> >>>> same line might be used to parse a bus (up to 0xff) or a
> >>>> slot (up to 0x1f). Instead of making things worst, rewrite
> >>>> using g_strsplit().
> 
> As there is few interest in fixing the issue with this patch,
> let me remind the 2 other approaches:
> 
> Klaus Herman:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg750101.html
> Geoffrey McRae:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg758182.html
> 
> That said, I'm done with this issue for 5.2.
> 
> Regards,
> 
> Phil.

What happens if we just revert bccb20c49df1bd683248a366021973901c11982f?

This is what I'm inclined to do for 5.2 ...


> >>>> Fixes: bccb20c49df ("Use qemu_strtoul() in set_pci_host_devaddr()")
> >>>> Reported-by: Klaus Herman <kherman@inbox.lv>
> >>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> >>>> ---
> >>>> v2: Free g_strsplit() with g_auto(GStrv) (Daniel)
> >>>> ---
> >>>>  hw/core/qdev-properties-system.c | 61 ++++++++++++++------------------
> >>>>  1 file changed, 27 insertions(+), 34 deletions(-)
> >>>>
> >>>> diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
> >>>> index 49bdd125814..36d4fd8b22a 100644
> >>>> --- a/hw/core/qdev-properties-system.c
> >>>> +++ b/hw/core/qdev-properties-system.c
> >>>> @@ -878,11 +878,11 @@ static void set_pci_host_devaddr(Object *obj, Visitor *v, const char *name,
> >>>>      DeviceState *dev = DEVICE(obj);
> >>>>      Property *prop = opaque;
> >>>>      PCIHostDeviceAddress *addr = qdev_get_prop_ptr(dev, prop);
> >>>> -    char *str, *p;
> >>>> -    const char *e;
> >>>> +    g_autofree char *str = NULL;
> >>>> +    g_auto(GStrv) col_s0 = NULL;
> >>>> +    g_auto(GStrv) dot_s = NULL;
> >>>> +    char **col_s;
> >>>>      unsigned long val;
> >>>> -    unsigned long dom = 0, bus = 0;
> >>>> -    unsigned int slot = 0, func = 0;
> >>>>  
> >>>>      if (dev->realized) {
> >>>>          qdev_prop_set_after_realize(dev, name, errp);
> >>>> @@ -893,57 +893,50 @@ static void set_pci_host_devaddr(Object *obj, Visitor *v, const char *name,
> >>>>          return;
> >>>>      }
> >>>>  
> >>>> -    p = str;
> >>>> -    if (qemu_strtoul(p, &e, 16, &val) < 0 || val > 0xffff || e == p) {
> >>>> +    col_s = col_s0 = g_strsplit(str, ":", 3);
> >>>> +    if (!col_s || !col_s[0] || !col_s[1]) {
> >>>>          goto inval;
> >>>>      }
> >>>> -    if (*e != ':') {
> >>>> -        goto inval;
> >>>> -    }
> >>>> -    bus = val;
> >>>>  
> >>>> -    p = (char *)e + 1;
> >>>> -    if (qemu_strtoul(p, &e, 16, &val) < 0 || val > 0x1f || e == p) {
> >>>> -        goto inval;
> >>>> -    }
> >>>> -    if (*e == ':') {
> >>>> -        dom = bus;
> >>>> -        bus = val;
> >>>> -        p = (char *)e + 1;
> >>>> -        if (qemu_strtoul(p, &e, 16, &val) < 0 || val > 0x1f || e == p) {
> >>>> +    /* domain */
> >>>> +    if (col_s[2]) {
> >>>> +        if (qemu_strtoul(col_s[0], NULL, 16, &val) < 0 || val > 0xffff) {
> >>>>              goto inval;
> >>>>          }
> >>>> +        addr->domain = val;
> >>>> +        col_s++;
> >>>> +    } else {
> >>>> +        addr->domain = 0;
> >>>>      }
> >>>> -    slot = val;
> >>>>  
> >>>> -    if (*e != '.') {
> >>>> +    /* bus */
> >>>> +    if (qemu_strtoul(col_s[0], NULL, 16, &val) < 0 || val > 0xff) {
> >>>>          goto inval;
> >>>>      }
> >>>> -    p = (char *)e + 1;
> >>>> -    if (qemu_strtoul(p, &e, 10, &val) < 0 || val > 7 || e == p) {
> >>>> -        goto inval;
> >>>> -    }
> >>>> -    func = val;
> >>>> +    addr->bus = val;
> >>>>  
> >>>> -    if (bus > 0xff) {
> >>>> +    /* <slot>.<func> */
> >>>> +    dot_s = g_strsplit(col_s[1], ".", 2);
> >>>> +    if (!dot_s || !dot_s[0] || !dot_s[1]) {
> >>>>          goto inval;
> >>>>      }
> >>>>  
> >>>> -    if (*e) {
> >>>> +    /* slot */
> >>>> +    if (qemu_strtoul(dot_s[0], NULL, 16, &val) < 0 || val > 0x1f) {
> >>>>          goto inval;
> >>>>      }
> >>>> +    addr->slot = val;
> >>>>  
> >>>> -    addr->domain = dom;
> >>>> -    addr->bus = bus;
> >>>> -    addr->slot = slot;
> >>>> -    addr->function = func;
> >>>> +    /* func */
> >>>> +    if (qemu_strtoul(dot_s[1], NULL, 10, &val) < 0 || val > 7) {
> >>>> +        goto inval;
> >>>> +    }
> >>>> +    addr->function = val;
> >>>>  
> >>>> -    g_free(str);
> >>>>      return;
> >>>>  
> >>>>  inval:
> >>>>      error_set_from_qdev_prop_error(errp, EINVAL, dev, prop, str);
> >>>> -    g_free(str);
> >>>>  }
> >>>>  
> >>>>  const PropertyInfo qdev_prop_pci_host_devaddr = {
> >>>>
> >>>
> >>
> >