[AVR32] Implement stacktrace support
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index b108dd8..599ec16 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -24,6 +24,9 @@
config GENERIC_HARDIRQS
def_bool y
+config STACKTRACE_SUPPORT
+ def_bool y
+
config HARDIRQS_SW_RESEND
def_bool y
diff --git a/arch/avr32/kernel/Makefile b/arch/avr32/kernel/Makefile
index 989fcd1..2d6d48f 100644
--- a/arch/avr32/kernel/Makefile
+++ b/arch/avr32/kernel/Makefile
@@ -11,3 +11,4 @@
obj-y += init_task.o switch_to.o cpu.o
obj-$(CONFIG_MODULES) += module.o avr32_ksyms.o
obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_STACKTRACE) += stacktrace.o
diff --git a/arch/avr32/kernel/stacktrace.c b/arch/avr32/kernel/stacktrace.c
new file mode 100644
index 0000000..9a68190
--- /dev/null
+++ b/arch/avr32/kernel/stacktrace.c
@@ -0,0 +1,53 @@
+/*
+ * Stack trace management functions
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/thread_info.h>
+
+register unsigned long current_frame_pointer asm("r7");
+
+struct stackframe {
+ unsigned long lr;
+ unsigned long fp;
+};
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+ unsigned long low, high;
+ unsigned long fp;
+ struct stackframe *frame;
+ int skip = trace->skip;
+
+ low = (unsigned long)task_stack_page(current);
+ high = low + THREAD_SIZE;
+ fp = current_frame_pointer;
+
+ while (fp >= low && fp <= (high - 8)) {
+ frame = (struct stackframe *)fp;
+
+ if (skip) {
+ skip--;
+ } else {
+ trace->entries[trace->nr_entries++] = frame->lr;
+ if (trace->nr_entries >= trace->max_entries)
+ break;
+ }
+
+ /*
+ * The next frame must be at a higher address than the
+ * current frame.
+ */
+ low = fp + 8;
+ fp = frame->fp;
+ }
+}