[dmidecode] [PATCH] Only decode one DMI table

[Jean Delvare]

Since version 3.0.0 of the SMBIOS specification, there can be
multiple entry points in memory, pointing to one or two DMI tables.
If both a 32-bit ("_SM_") entry point and a 64-bit ("_SM3_") entry
point are present, the specification requires that the latter points
to a table which is a super-set of the table pointed to by the
former. Therefore it makes no sense to decode both.

Per specification, look for a 64-bit ("_SM3_") entry point first, and
if we can't find any, look for a 32-bit ("_SM_" or "_DMI") entry
point.

This fixed bug #50022:
https://savannah.nongnu.org/bugs/?50022
---
 dmidecode.c |   17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

--- dmidecode.orig/dmidecode.c  2016-09-07 22:17:04.486138537 +0200
+++ dmidecode/dmidecode.c       2017-01-12 17:08:49.231245228 +0100
@@ -4925,28 +4925,35 @@ int main(int argc, char * const argv[])
                goto exit_free;
        }
 
-       for (fp = 0; fp <= 0xFFF0; fp += 16)
+       for (fp = 0; fp <= 0xFFE0; fp += 16)
        {
-               if (memcmp(buf + fp, "_SM3_", 5) == 0 && fp <= 0xFFE0)
+               if (memcmp(buf + fp, "_SM3_", 5) == 0)
                {
                        if (smbios3_decode(buf + fp, opt.devmem, 0))
                        {
                                found++;
-                               fp += 16;
+                               goto done;
                        }
                }
-               else if (memcmp(buf + fp, "_SM_", 4) == 0 && fp <= 0xFFE0)
+       }
+
+       for (fp = 0; fp <= 0xFFF0; fp += 16)
+       {
+               if (memcmp(buf + fp, "_SM_", 4) == 0 && fp <= 0xFFE0)
                {
                        if (smbios_decode(buf + fp, opt.devmem, 0))
                        {
                                found++;
-                               fp += 16;
+                               goto done;
                        }
                }
                else if (memcmp(buf + fp, "_DMI_", 5) == 0)
                {
                        if (legacy_decode(buf + fp, opt.devmem, 0))
+                       {
                                found++;
+                               goto done;
+                       }
                }
        }
 


-- 
Jean Delvare
SUSE L3 Support