sh: Make is_valid_bugaddr() more intelligent on nommu.
Currently is_valid_bugaddr() is true for anything >= PAGE_OFFSET, which
happens to be 0 on nommu configurations. Make this a bit smarter by just
reading in the opcode and comparing it against the trap type that we
already know. Follows the logic from avr32.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index a3bdc68..438f1eb 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -4,6 +4,7 @@
#include <linux/kdebug.h>
#include <linux/signal.h>
#include <linux/sched.h>
+#include <linux/uaccess.h>
#include <asm/system.h>
#ifdef CONFIG_BUG
@@ -21,7 +22,14 @@
int is_valid_bugaddr(unsigned long addr)
{
- return addr >= PAGE_OFFSET;
+ unsigned short opcode;
+
+ if (addr < PAGE_OFFSET)
+ return 0;
+ if (probe_kernel_address((u16 *)addr, opcode))
+ return 0;
+
+ return opcode == TRAPA_BUG_OPCODE;
}
#endif