powerpc/pseries: Correct buffer parsing in update_dt_node()

Correct parsing of the buffer returned from ibm,update-properties. The first
element is a length and the path to the property which is slightly different
from the list of properties in the buffer so we need to specifically
handle this.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 16 insertions, 4 deletions

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 4c184ceb2450..3d01eee9ffb1 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -134,6 +134,7 @@ static int update_dt_node(u32 phandle, s32 scope)
         char *prop_data;
         char *rtas_buf;
         int update_properties_token;
+        u32 vd;
 
         update_properties_token = rtas_token("ibm,update-properties");
         if (update_properties_token == RTAS_UNKNOWN_SERVICE)
@@ -160,13 +161,24 @@ static int update_dt_node(u32 phandle, s32 scope)
 
                 prop_data = rtas_buf + sizeof(*upwa);
 
-                for (i = 0; i < upwa->nprops; i++) {
+                /* The first element of the buffer is the path of the node
+                 * being updated in the form of a 8 byte string length
+                 * followed by the string. Skip past this to get to the
+                 * properties being updated.
+                 */
+                vd = *prop_data++;
+                prop_data += vd;
+
+                /* The path we skipped over is counted as one of the elements
+                 * returned so start counting at one.
+                 */
+                for (i = 1; i < upwa->nprops; i++) {
                         char *prop_name;
-                        u32 vd;
 
-                        prop_name = prop_data + 1;
+                        prop_name = prop_data;
                         prop_data += strlen(prop_name) + 1;
-                        vd = *prop_data++;
+                        vd = *(u32 *)prop_data;
+                        prop_data += sizeof(vd);
 
                         switch (vd) {
                         case 0x00000000: