avr32: Do stricter stack checking in the exception handler

Don't do a stack dump if the stack pointer is outside the memory area
reserved for stack.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

cpu/at32ap/exception.c

@@ -111,7 +111,8 @@ void do_unknown_exception(unsigned int ecr, struct pt_regs *regs)
 	printf("CPU Mode: %s\n", cpu_modes[mode]);
 
 	/* Avoid exception loops */
-	if (regs->sp < CFG_SDRAM_BASE || regs->sp >= gd->stack_end)
+	if (regs->sp < (gd->stack_end - CONFIG_STACKSIZE)
+			|| regs->sp >= gd->stack_end)
 		printf("\nStack pointer seems bogus, won't do stack dump\n");
 	else
 		dump_mem("\nStack: ", regs->sp, gd->stack_end);