[ARM] 5383/2: unwind: Add core support for ARM stack unwinding

This patch adds the main functionality for parsing the stack unwinding
information generated by the ARM EABI toolchains. The unwinding
information consists of an index with a pair of words per function and a
table with unwinding instructions. For more information, see "Exception
Handling ABI for the ARM Architecture" at:

http://infocenter.arm.com/help/topic/com.arm.doc.subset.swdev.abi/index.html

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index f68ca0fb0ed7..57eb0f6f6005 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -27,6 +27,7 @@
 #include <asm/system.h>
 #include <asm/unistd.h>
 #include <asm/traps.h>
+#include <asm/unwind.h>
 
 #include "ptrace.h"
 #include "signal.h"
@@ -61,6 +62,7 @@ void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long
                 dump_mem("Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
 }
 
+#ifndef CONFIG_ARM_UNWIND
 /*
  * Stack pointers should always be within the kernels view of
  * physical memory.  If it is not there, then we can't dump
@@ -74,6 +76,7 @@ static int verify_stack(unsigned long sp)
 
         return 0;
 }
+#endif
 
 /*
  * Dump out the contents of some memory nicely...
@@ -150,6 +153,12 @@ static void dump_instr(struct pt_regs *regs)
         set_fs(fs);
 }
 
+#ifdef CONFIG_ARM_UNWIND
+static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
+{
+        unwind_backtrace(regs, tsk);
+}
+#else
 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
         unsigned int fp, mode;
@@ -184,6 +193,7 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
         if (ok)
                 c_backtrace(fp, mode);
 }
+#endif
 
 void dump_stack(void)
 {