Re: DMI year "00" + ACPI [was: DMI: fix dmi_get_year year parsing]

[Matthias Pfaller]

Jiri Slaby wrote:
> On 07/08/2009 09:03 AM, Matthias Pfaller wrote:
> > Jiri Slaby wrote:
> > > On 07/08/2009 08:46 AM, Matthias Pfaller wrote:
> > > > Jiri Slaby wrote:
> > > > > Don't guess a year number base. Use 10 instead, since year may
> > > > > be 2-digit starting with 0, so that we would end up in base equal
> > > > > to 8.
> > > > >
> > > > > Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
> > > > > Reported-by: Matthias Pfaller <leo@xxxxxxxx>
> > > > > ---
> > > > >  drivers/firmware/dmi_scan.c |    2 +-
> > > > >  1 files changed, 1 insertions(+), 1 deletions(-)
> > > > >
> > > > > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
> > > > > index 6071078..8fe0f6e 100644
> > > > > --- a/drivers/firmware/dmi_scan.c
> > > > > +++ b/drivers/firmware/dmi_scan.c
> > > > > @@ -611,7 +611,7 @@ int dmi_get_year(int field)
> > > > >          return 0;
> > > > >  
> > > > >      s += 1;
> > > > > -    year = simple_strtoul(s, NULL, 0);
> > > > > +    year = simple_strtoul(s, NULL, 10);
> > > > >      if (year && year < 100) {    /* 2-digit year */
> > > > >          year += 1900;
> > > > >          if (year < 1996)    /* no dates < spec 1.0 */
> > > > I just noticed, that this is not enough, because this will still fail
> > > > for xxx/xx/00. I suggest the following patch:
> > > Actually the patch below is not correct. Standard says consider xx/xx/yy
> > > as 19yy, not 20yy.
> > >
> > > BTW. the patch above is not useful, reporting 1908 and 1909 as a year is
> > > almost the same as 1900.
> > Sorry, I don't understand.
>
> Nevermind, you're right. Both patches are OK, however we might hit a
> regression with 00/00/00 entries so that acpi gets unintentionally armed
> now for them (ACPI checks year == 0). I don't know if it's worth it. Any
> ideas?

There are bioses with 00/00/00? How about that:

--- dmi_scan.c.orig     Thu Jul  9 03:34:48 2009
+++ dmi_scan.c  Thu Jul  9 03:38:19 2009
@@ -352,17 +352,36 @@
                return -1;
        if (*s == '\0')
                return 0;
+
+       /* Month must not be zero */
+       if (simple_strtoul(s, NULL, 10) == 0)
+               return 0;
+
+       /* Look for day of month */
+       s = strchr(s, '/');
+       if (!s)
+               return 0;
+
+       /* Day of month must not be zero */
+       s += 1;
+       if (simple_strtoul(s, NULL, 10) == 0)
+               return 0;
+
+       /* Look for year */
        s = strrchr(s, '/');
        if (!s)
                return 0;
         s += 1;
-       year = simple_strtoul(s, NULL, 0);
-       if (year && year < 100) {       /* 2-digit year */
-               year += 1900;
-               if (year < 1996)        /* no dates < spec 1.0 */
-                       year += 100;
+       if (s[0] == '0' && s[1] == '0' && s[2] == '\0') {
+               year = 2000;
+       } else {
+               year = simple_strtoul(s, NULL, 10);
+               if (year && year < 100) {       /* 2-digit year */
+                       year += 1900;
+                       if (year < 1996)        /* no dates < spec 1.0 */
+                               year += 100;
+               }
        }
-
        return year;
 }
--
Matthias Pfaller                          Software Entwicklung
marco Systemanalyse und Entwicklung GmbH  Tel   +49 8131 5161 41
Hans-Böckler-Str. 2, D 85221 Dachau       Fax   +49 8131 5161 66
http://www.marco.de/                      Email leo@xxxxxxxx
Geschäftsführer Martin Reuter             HRB 171775 Amtsgericht München
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/