Blackfin: add preliminary support for STACKTRACE
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile
index fd4d432..a66dda4 100644
--- a/arch/blackfin/kernel/Makefile
+++ b/arch/blackfin/kernel/Makefile
@@ -23,6 +23,7 @@
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_KGDB_TESTS) += kgdb_test.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+obj-$(CONFIG_STACKTRACE) += stacktrace.o
# the kgdb test puts code into L2 and without linker
# relaxation, we need to force long calls to/from it
diff --git a/arch/blackfin/kernel/stacktrace.c b/arch/blackfin/kernel/stacktrace.c
new file mode 100644
index 0000000..30301e1
--- /dev/null
+++ b/arch/blackfin/kernel/stacktrace.c
@@ -0,0 +1,53 @@
+/*
+ * Blackfin stacktrace code (mostly copied from avr32)
+ *
+ * Copyright 2009 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/thread_info.h>
+#include <linux/module.h>
+
+register unsigned long current_frame_pointer asm("FP");
+
+struct stackframe {
+ unsigned long fp;
+ unsigned long rets;
+};
+
+/*
+ * 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 - sizeof(*frame))) {
+ frame = (struct stackframe *)fp;
+
+ if (skip) {
+ skip--;
+ } else {
+ trace->entries[trace->nr_entries++] = frame->rets;
+ if (trace->nr_entries >= trace->max_entries)
+ break;
+ }
+
+ /*
+ * The next frame must be at a higher address than the
+ * current frame.
+ */
+ low = fp + sizeof(*frame);
+ fp = frame->fp;
+ }
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
