4 files changed, 52 insertions, 18 deletions

diff --git a/arch/sh/include/asm/bug.h b/arch/sh/include/asm/bug.h
index c01718040166..d02c01b3e6b9 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 d3d3837c5e1b..c367ed3373c5 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 ab79e1f4fbe0..f9e2ceb94d9b 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 3dc551453e28..1e65c07b3e18 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 */