ARM: 9254/1: mm: Provide better message when kernel fault

If there is a kernel fault, see do_kernel_fault(), we only print
the generic "paging request" or "NULL pointer dereference" message
which don't show read, write or excute information, let's provide
better fault message for them.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

arch/arm/mm/fault.c

@@ -111,8 +111,9 @@ static void die_kernel_fault(const char *msg, struct mm_struct *mm,
 {
 	bust_spinlocks(1);
 	pr_alert("8<--- cut here ---\n");
-	pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
-		 msg, addr);
+	pr_alert("Unable to handle kernel %s at virtual address %08lx when %s\n",
+		 msg, addr, fsr & FSR_LNX_PF ? "execute" :
+		 fsr & FSR_WRITE ? "write" : "read");
 
 	show_pte(KERN_ALERT, mm, addr);
 	die("Oops", regs, fsr);