microblaze: Add stack unwinder
Implement intelligent backtracing by searching for stack frame creation,
and emitting only return addresses. Use print_hex_dump() to display the
entire binary kernel stack.
Limitation: MMU kernels are not currently able to trace beyond a system trap
(interrupt, syscall, etc.). It is the intent of this patch to provide
infrastructure that can be extended to add this capability later.
Changes from V1:
* Removed checks in find_frame_creation() that prevented location of the frame
creation instruction in heavily optimized code
* Various formatting/commenting/file location tweaks per review comments
* Dropped Kconfig option to enable STACKTRACE as something logically separate
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S
index 995a212..7811954 100644
--- a/arch/microblaze/kernel/hw_exception_handler.S
+++ b/arch/microblaze/kernel/hw_exception_handler.S
@@ -78,9 +78,6 @@
#include <asm/asm-offsets.h>
/* Helpful Macros */
-#ifndef CONFIG_MMU
-#define EX_HANDLER_STACK_SIZ (4*19)
-#endif
#define NUM_TO_REG(num) r ## num
#ifdef CONFIG_MMU
@@ -988,6 +985,7 @@
.end _unaligned_data_exception
#endif /* CONFIG_MMU */
+.global ex_handler_unhandled
ex_handler_unhandled:
/* FIXME add handle function for unhandled exception - dump register */
bri 0