From 12fbde92a26da61eda9f2ff0ba3c316779163f10 Mon Sep 17 00:00:00 2001

From: Jean Delvare <jdelvare@suse.de>

Date: Fri, 20 Jan 2017 10:57:12 +0100

Subject: [PATCH 18/19] Only decode one DMI table

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 fixes bug #50022:

https://savannah.nongnu.org/bugs/?50022

---

 CHANGELOG   |  6 ++++++

 dmidecode.c | 19 ++++++++++++++-----

 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index ac748b0..67aef99 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -1,3 +1,9 @@

+2017-01-20  Jean Delvare  <jdelvare@suse.de>

+

+	* dmidecode.c: Only decode one DMI table.

+	  This fixes Savannah bug #50022:

+	  https://savannah.nongnu.org/bugs/?50022

+

 2016-09-22  Jean Delvare  <jdelvare@suse.de>

 	* README: Explain that we can no longer support Cygwin.

diff --git a/dmidecode.c b/dmidecode.c

index 3993592..4b46a13 100644

--- a/dmidecode.c

+++ b/dmidecode.c

@@ -4925,28 +4925,37 @@ memory_scan:

 		goto exit_free;

 	}

-	for (fp = 0; fp <= 0xFFF0; fp += 16)

+	/* Look for a 64-bit entry point first */

+	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)

+	}

+

+	/* If none found, look for a 32-bit entry point */

+	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;

+			}

 		}

 	}

-- 

2.9.3