On 06/15/15 16:23, Markus Armbruster wrote: > Laszlo Ersek <ler...@redhat.com> writes: > >> Cc: Markus Armbruster <arm...@redhat.com> >> Cc: Marcel Apfelbaum <mar...@redhat.com> >> Cc: Michael S. Tsirkin <m...@redhat.com> >> Signed-off-by: Laszlo Ersek <ler...@redhat.com> >> --- >> >> Notes: >> v4: >> - unchanged >> >> v3: >> - new in v3 >> >> hw/core/sysbus.c | 16 ++++++---------- >> 1 file changed, 6 insertions(+), 10 deletions(-) >> >> diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c >> index b53c351..0ebb4e2 100644 >> --- a/hw/core/sysbus.c >> +++ b/hw/core/sysbus.c >> @@ -281,19 +281,15 @@ static void sysbus_dev_print(Monitor *mon, DeviceState >> *dev, int indent) >> static char *sysbus_get_fw_dev_path(DeviceState *dev) >> { >> SysBusDevice *s = SYS_BUS_DEVICE(dev); >> - char path[40]; >> - int off; >> - >> - off = snprintf(path, sizeof(path), "%s", qdev_fw_name(dev)); >> >> if (s->num_mmio) { >> - snprintf(path + off, sizeof(path) - off, "@"TARGET_FMT_plx, >> - s->mmio[0].addr); >> - } else if (s->num_pio) { >> - snprintf(path + off, sizeof(path) - off, "@i%04x", s->pio[0]); >> + return g_strdup_printf("%s@"TARGET_FMT_plx, qdev_fw_name(dev), > > I'd put a space between "%s@" and TARGET_FMT_plx.
I tried to copy the original format string very carefully, but you do have a point. I'll do it in the next version. > >> + s->mmio[0].addr); >> } >> - >> - return g_strdup(path); >> + if (s->num_pio) { >> + return g_strdup_printf("%s@i%04x", qdev_fw_name(dev), s->pio[0]); >> + } >> + return g_strdup(qdev_fw_name(dev)); >> } >> >> void sysbus_add_io(SysBusDevice *dev, hwaddr addr, > > Would be nice if we didn't have to triplicate qdev_fw_name(), but I > don't have better ideas. Right, I could "cache it" in a local variable, but then I'd have to triplicate the variable reference. And, runtime-wise, qdev_fw_name() is called only once, it's just spelled out thrice in the source. > > Bonus: no arbitrary length limit. Before your patch, it's 39 > characters, and the code breaks catastrophically when qdev_fw_name() is > longer: the second snprintf() is called with its first argument pointing > beyond path[], and its second argument underflowing to a huge size. > Textbook example of how not to use snprintf(). Worth mentioning in the > commit message? I was afraid that bashing on old code would only earn me some ire (not from you, mind you -- in general), so I didn't mention this fact in the commit message on purpose. :) I will, in the next version. > Reviewed-by: Markus Armbruster <arm...@redhat.com> > Thanks! Laszlo