[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 (file)
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -24,6 +24,9 @@ config GENERIC_GPIO
 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 (file)
--- a/arch/avr32/kernel/Makefile
+++ b/arch/avr32/kernel/Makefile
@@ -11,3 +11,4 @@ obj-y                         += signal.o sys_avr32.o process.o time.o
 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 (file)
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;
+       }
+}