[PATCH] ppc64: firmware workaround

Recent gcc 4.0 testing uncovered a firmware issue.  Some properties are larger
than 31 bytes and due to gcc 4.0s better stack allocation this overflow ran
over non volatile register storage.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/ppc64/kernel/prom_init.c b/arch/ppc64/kernel/prom_init.c
index b0b784f9a4e..35ec42de962 100644
--- a/arch/ppc64/kernel/prom_init.c
+++ b/arch/ppc64/kernel/prom_init.c
@@ -1555,6 +1555,12 @@ static void __init scan_dt_build_strings(phandle node, unsigned long *mem_start,
         }
 }
 
+/*
+ * The Open Firmware 1275 specification states properties must be 31 bytes or
+ * less, however not all firmwares obey this. Make it 64 bytes to be safe.
+ */
+#define MAX_PROPERTY_NAME 64
+
 static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
                                         unsigned long *mem_end)
 {
@@ -1564,7 +1570,7 @@ static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
         unsigned long soff;
         unsigned char *valp;
         unsigned long offset = reloc_offset();
-        char pname[32];
+        char pname[MAX_PROPERTY_NAME];
         char *path;
 
         path = RELOC(prom_scratch);