Blackfin: add preliminary support for STACKTRACE

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index d68cb0d..77ec14f 100644 (file)
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -55,6 +55,9 @@ config FORCE_MAX_ZONEORDER
 config GENERIC_CALIBRATE_DELAY
        def_bool y
 
+config STACKTRACE_SUPPORT
+       def_bool y
+
 config TRACE_IRQFLAGS_SUPPORT
        def_bool y
 

diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile
index fd4d432..a66dda4 100644 (file)
--- a/arch/blackfin/kernel/Makefile
+++ b/arch/blackfin/kernel/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_MODULES)                += module.o
 obj-$(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 (file)
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);