4 files changed, 52 insertions, 18 deletions
diff --git a/arch/sh/include/asm/bug.h b/arch/sh/include/asm/bug.h
index c0171804016..d02c01b3e6b 100644
--- a/arch/sh/include/asm/bug.h
+++ b/arch/sh/include/asm/bug.h
@@ -2,6 +2,7 @@
 #define __ASM_SH_BUG_H
 
 #define TRAPA_BUG_OPCODE	0xc33e	/* trapa #0x3e */
+#define BUGFLAG_UNWINDER	(1 << 1)
 
 #ifdef CONFIG_GENERIC_BUG
 #define HAVE_ARCH_BUG
@@ -72,6 +73,36 @@ do {							\
 	unlikely(__ret_warn_on);				\
 })
 
+#define UNWINDER_BUG()					\
+do {							\
+	__asm__ __volatile__ (				\
+		"1:\t.short %O0\n"			\
+		_EMIT_BUG_ENTRY				\
+		 :					\
+		 : "n" (TRAPA_BUG_OPCODE),		\
+		   "i" (__FILE__),			\
+		   "i" (__LINE__),			\
+		   "i" (BUGFLAG_UNWINDER),		\
+		   "i" (sizeof(struct bug_entry)));	\
+} while (0)
+
+#define UNWINDER_BUG_ON(x) ({					\
+	int __ret_unwinder_on = !!(x);				\
+	if (__builtin_constant_p(__ret_unwinder_on)) {		\
+		if (__ret_unwinder_on)				\
+			UNWINDER_BUG();				\
+	} else {						\
+		if (unlikely(__ret_unwinder_on))		\
+			UNWINDER_BUG();				\
+	}							\
+	unlikely(__ret_unwinder_on);				\
+})
+
+#else
+
+#define UNWINDER_BUG	BUG
+#define UNWINDER_BUG_ON	BUG_ON
+
 #endif /* CONFIG_GENERIC_BUG */
 
 #include <asm-generic/bug.h>
diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h
index d3d3837c5e1..c367ed3373c 100644
--- a/arch/sh/include/asm/dwarf.h
+++ b/arch/sh/include/asm/dwarf.h
@@ -265,10 +265,7 @@ struct dwarf_frame {
 
 	unsigned long pc;
 
-	struct dwarf_reg *regs;
-	unsigned int num_regs;	/* how many regs are allocated? */
-
-	unsigned int depth;	/* what level are we in the callstack? */
+	struct list_head reg_list;
 
 	unsigned long cfa;
 
@@ -292,20 +289,15 @@ struct dwarf_frame {
  *	@flags: Describes how to calculate the value of this register
  */
 struct dwarf_reg {
+	struct list_head link;
+
+	unsigned int number;
+
 	unsigned long addr;
 	unsigned long flags;
 #define DWARF_REG_OFFSET	(1 << 0)
-};
-
-/**
- *	dwarf_stack - a DWARF stack contains a collection of DWARF frames
- *	@depth: the number of frames in the stack
- *	@level: an array of DWARF frames, indexed by stack level
- *
- */
-struct dwarf_stack {
-	unsigned int depth;
-	struct dwarf_frame **level;
+#define DWARF_VAL_OFFSET	(1 << 1)
+#define DWARF_UNDEFINED		(1 << 2)
 };
 
 /*
@@ -370,17 +362,16 @@ static inline unsigned int DW_CFA_operand(unsigned long insn)
 #define DW_EXT_HI	0xffffffff
 #define DW_EXT_DWARF64	DW_EXT_HI
 
-extern void dwarf_unwinder_init(void);
-
 extern struct dwarf_frame *dwarf_unwind_stack(unsigned long,
 					      struct dwarf_frame *);
-#endif /* __ASSEMBLY__ */
+#endif /* !__ASSEMBLY__ */
 
 #define CFI_STARTPROC	.cfi_startproc
 #define CFI_ENDPROC	.cfi_endproc
 #define CFI_DEF_CFA	.cfi_def_cfa
 #define CFI_REGISTER	.cfi_register
 #define CFI_REL_OFFSET	.cfi_rel_offset
+#define CFI_UNDEFINED	.cfi_undefined
 
 #else
 
@@ -394,6 +385,7 @@ extern struct dwarf_frame *dwarf_unwind_stack(unsigned long,
 #define CFI_DEF_CFA	CFI_IGNORE
 #define CFI_REGISTER	CFI_IGNORE
 #define CFI_REL_OFFSET	CFI_IGNORE
+#define CFI_UNDEFINED	CFI_IGNORE
 
 #ifndef __ASSEMBLY__
 static inline void dwarf_unwinder_init(void)
diff --git a/arch/sh/include/asm/system.h b/arch/sh/include/asm/system.h
index ab79e1f4fbe..f9e2ceb94d9 100644
--- a/arch/sh/include/asm/system.h
+++ b/arch/sh/include/asm/system.h
@@ -181,6 +181,11 @@ BUILD_TRAP_HANDLER(breakpoint);
 BUILD_TRAP_HANDLER(singlestep);
 BUILD_TRAP_HANDLER(fpu_error);
 BUILD_TRAP_HANDLER(fpu_state_restore);
+BUILD_TRAP_HANDLER(unwinder);
+
+#ifdef CONFIG_BUG
+extern void handle_BUG(struct pt_regs *);
+#endif
 
 #define arch_align_stack(x) (x)
 
diff --git a/arch/sh/include/asm/unwinder.h b/arch/sh/include/asm/unwinder.h
index 3dc551453e2..1e65c07b3e1 100644
--- a/arch/sh/include/asm/unwinder.h
+++ b/arch/sh/include/asm/unwinder.h
@@ -22,4 +22,10 @@ extern void stack_reader_dump(struct task_struct *, struct pt_regs *,
 			      unsigned long *, const struct stacktrace_ops *,
 			      void *);
 
+/*
+ * Used by fault handling code to signal to the unwinder code that it
+ * should switch to a different unwinder.
+ */
+extern int unwinder_faulted;
+
 #endif /* _LINUX_UNWINDER_H */