Remove stack unwinder for now

It has caused more problems than it ever really solved, and is
apparently not getting cleaned up and fixed.  We can put it back when
it's stable and isn't likely to make warning or bug events worse.

In the meantime, enable frame pointers for more readable stack traces.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

17 files changed, 3 insertions, 1870 deletions

diff --git a/Makefile b/Makefile
index dc82462b68b..4a472038793 100644
--- a/Makefile
+++ b/Makefile
@@ -496,11 +496,6 @@ else
 CFLAGS		+= -fomit-frame-pointer
 endif
 
-ifdef CONFIG_UNWIND_INFO
-CFLAGS		+= -fasynchronous-unwind-tables
-LDFLAGS_vmlinux	+= --eh-frame-hdr
-endif
-
 ifdef CONFIG_DEBUG_INFO
 CFLAGS		+= -g
 endif
diff --git a/arch/i386/defconfig b/arch/i386/defconfig
index 3265208e589..e075ff05c46 100644
--- a/arch/i386/defconfig
+++ b/arch/i386/defconfig
@@ -1493,8 +1493,6 @@ CONFIG_DEBUG_BUGVERBOSE=y
 # CONFIG_DEBUG_VM is not set
 # CONFIG_DEBUG_LIST is not set
 # CONFIG_FRAME_POINTER is not set
-CONFIG_UNWIND_INFO=y
-CONFIG_STACK_UNWIND=y
 # CONFIG_FORCED_INLINING is not set
 # CONFIG_HEADERS_CHECK is not set
 # CONFIG_RCU_TORTURE_TEST is not set
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index de34b7fed3c..06461b8b715 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -979,38 +979,6 @@ ENTRY(spurious_interrupt_bug)
 	jmp error_code
 	CFI_ENDPROC
 
-#ifdef CONFIG_STACK_UNWIND
-ENTRY(arch_unwind_init_running)
-	CFI_STARTPROC
-	movl	4(%esp), %edx
-	movl	(%esp), %ecx
-	leal	4(%esp), %eax
-	movl	%ebx, PT_EBX(%edx)
-	xorl	%ebx, %ebx
-	movl	%ebx, PT_ECX(%edx)
-	movl	%ebx, PT_EDX(%edx)
-	movl	%esi, PT_ESI(%edx)
-	movl	%edi, PT_EDI(%edx)
-	movl	%ebp, PT_EBP(%edx)
-	movl	%ebx, PT_EAX(%edx)
-	movl	$__USER_DS, PT_DS(%edx)
-	movl	$__USER_DS, PT_ES(%edx)
-	movl	$0, PT_GS(%edx)
-	movl	%ebx, PT_ORIG_EAX(%edx)
-	movl	%ecx, PT_EIP(%edx)
-	movl	12(%esp), %ecx
-	movl	$__KERNEL_CS, PT_CS(%edx)
-	movl	%ebx, PT_EFLAGS(%edx)
-	movl	%eax, PT_OLDESP(%edx)
-	movl	8(%esp), %eax
-	movl	%ecx, 8(%esp)
-	movl	PT_EBX(%edx), %ebx
-	movl	$__KERNEL_DS, PT_OLDSS(%edx)
-	jmpl	*%eax
-	CFI_ENDPROC
-ENDPROC(arch_unwind_init_running)
-#endif
-
 ENTRY(kernel_thread_helper)
 	pushl $0		# fake return address for unwinder
 	CFI_STARTPROC
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 2b30dbf8d11..0efad8aeb41 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -94,11 +94,6 @@ asmlinkage void spurious_interrupt_bug(void);
 asmlinkage void machine_check(void);
 
 int kstack_depth_to_print = 24;
-#ifdef CONFIG_STACK_UNWIND
-static int call_trace = 1;
-#else
-#define call_trace (-1)
-#endif
 ATOMIC_NOTIFIER_HEAD(i386die_chain);
 
 int register_die_notifier(struct notifier_block *nb)
@@ -152,33 +147,6 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo,
 	return ebp;
 }
 
-struct ops_and_data {
-	struct stacktrace_ops *ops;
-	void *data;
-};
-
-static asmlinkage int
-dump_trace_unwind(struct unwind_frame_info *info, void *data)
-{
-	struct ops_and_data *oad = (struct ops_and_data *)data;
-	int n = 0;
-	unsigned long sp = UNW_SP(info);
-
-	if (arch_unw_user_mode(info))
-		return -1;
-	while (unwind(info) == 0 && UNW_PC(info)) {
-		n++;
-		oad->ops->address(oad->data, UNW_PC(info));
-		if (arch_unw_user_mode(info))
-			break;
-		if ((sp & ~(PAGE_SIZE - 1)) == (UNW_SP(info) & ~(PAGE_SIZE - 1))
-		    && sp > UNW_SP(info))
-			break;
-		sp = UNW_SP(info);
-	}
-	return n;
-}
-
 #define MSG(msg) ops->warning(data, msg)
 
 void dump_trace(struct task_struct *task, struct pt_regs *regs,
@@ -190,41 +158,6 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 	if (!task)
 		task = current;
 
-	if (call_trace >= 0) {
-		int unw_ret = 0;
-		struct unwind_frame_info info;
-		struct ops_and_data oad = { .ops = ops, .data = data };
-
-		if (regs) {
-			if (unwind_init_frame_info(&info, task, regs) == 0)
-				unw_ret = dump_trace_unwind(&info, &oad);
-		} else if (task == current)
-			unw_ret = unwind_init_running(&info, dump_trace_unwind,
-						      &oad);
-		else {
-			if (unwind_init_blocked(&info, task) == 0)
-				unw_ret = dump_trace_unwind(&info, &oad);
-		}
-		if (unw_ret > 0) {
-			if (call_trace == 1 && !arch_unw_user_mode(&info)) {
-				ops->warning_symbol(data,
-					     "DWARF2 unwinder stuck at %s",
-					     UNW_PC(&info));
-				if (UNW_SP(&info) >= PAGE_OFFSET) {
-					MSG("Leftover inexact backtrace:");
-					stack = (void *)UNW_SP(&info);
-					if (!stack)
-						return;
-					ebp = UNW_FP(&info);
-				} else
-					MSG("Full inexact backtrace again:");
-			} else if (call_trace >= 1)
-				return;
-			else
-				MSG("Full inexact backtrace again:");
-		} else
-			MSG("Inexact backtrace:");
-	}
 	if (!stack) {
 		unsigned long dummy;
 		stack = &dummy;
@@ -1258,19 +1191,3 @@ static int __init kstack_setup(char *s)
 	return 1;
 }
 __setup("kstack=", kstack_setup);
-
-#ifdef CONFIG_STACK_UNWIND
-static int __init call_trace_setup(char *s)
-{
-	if (strcmp(s, "old") == 0)
-		call_trace = -1;
-	else if (strcmp(s, "both") == 0)
-		call_trace = 0;
-	else if (strcmp(s, "newfallback") == 0)
-		call_trace = 1;
-	else if (strcmp(s, "new") == 2)
-		call_trace = 2;
-	return 1;
-}
-__setup("call_trace=", call_trace_setup);
-#endif
diff --git a/arch/x86_64/Makefile b/arch/x86_64/Makefile
index b471b8550d0..2941a915d4e 100644
--- a/arch/x86_64/Makefile
+++ b/arch/x86_64/Makefile
@@ -45,9 +45,7 @@ cflags-kernel-$(CONFIG_REORDER) += -ffunction-sections
 # actually it makes the kernel smaller too.
 cflags-y += -fno-reorder-blocks
 cflags-y += -Wno-sign-compare
-ifneq ($(CONFIG_UNWIND_INFO),y)
 cflags-y += -fno-asynchronous-unwind-tables
-endif
 ifneq ($(CONFIG_DEBUG_INFO),y)
 # -fweb shrinks the kernel a bit, but the difference is very small
 # it also messes up debugging, so don't use it for now.
diff --git a/arch/x86_64/defconfig b/arch/x86_64/defconfig
index 1a1c6a1a299..ac80b1209fc 100644
--- a/arch/x86_64/defconfig
+++ b/arch/x86_64/defconfig
@@ -1523,8 +1523,6 @@ CONFIG_DEBUG_FS=y
 # CONFIG_DEBUG_VM is not set
 # CONFIG_DEBUG_LIST is not set
 # CONFIG_FRAME_POINTER is not set
-CONFIG_UNWIND_INFO=y
-CONFIG_STACK_UNWIND=y
 # CONFIG_FORCED_INLINING is not set
 # CONFIG_HEADERS_CHECK is not set
 # CONFIG_RCU_TORTURE_TEST is not set
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 601d332c4b7..9f5dac64aa8 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -1155,36 +1155,3 @@ ENTRY(call_softirq)
 	ret
 	CFI_ENDPROC
 ENDPROC(call_softirq)
-
-#ifdef CONFIG_STACK_UNWIND
-ENTRY(arch_unwind_init_running)
-	CFI_STARTPROC
-	movq	%r15, R15(%rdi)
-	movq	%r14, R14(%rdi)
-	xchgq	%rsi, %rdx
-	movq	%r13, R13(%rdi)
-	movq	%r12, R12(%rdi)
-	xorl	%eax, %eax
-	movq	%rbp, RBP(%rdi)
-	movq	%rbx, RBX(%rdi)
-	movq	(%rsp), %rcx
-	movq	%rax, R11(%rdi)
-	movq	%rax, R10(%rdi)
-	movq	%rax, R9(%rdi)
-	movq	%rax, R8(%rdi)
-	movq	%rax, RAX(%rdi)
-	movq	%rax, RCX(%rdi)
-	movq	%rax, RDX(%rdi)
-	movq	%rax, RSI(%rdi)
-	movq	%rax, RDI(%rdi)
-	movq	%rax, ORIG_RAX(%rdi)
-	movq	%rcx, RIP(%rdi)
-	leaq	8(%rsp), %rcx
-	movq	$__KERNEL_CS, CS(%rdi)
-	movq	%rax, EFLAGS(%rdi)
-	movq	%rcx, RSP(%rdi)
-	movq	$__KERNEL_DS, SS(%rdi)
-	jmpq	*%rdx
-	CFI_ENDPROC
-ENDPROC(arch_unwind_init_running)
-#endif
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index b54ccc07f37..1d9eb6db732 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -110,11 +110,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
 }
 
 int kstack_depth_to_print = 12;
-#ifdef CONFIG_STACK_UNWIND
-static int call_trace = 1;
-#else
-#define call_trace (-1)
-#endif
 
 #ifdef CONFIG_KALLSYMS
 void printk_address(unsigned long address)
@@ -217,32 +212,6 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
 	return NULL;
 }
 
-struct ops_and_data {
-	struct stacktrace_ops *ops;
-	void *data;
-};
-
-static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
-{
-	struct ops_and_data *oad = (struct ops_and_data *)context;
-	int n = 0;
-	unsigned long sp = UNW_SP(info);
-
-	if (arch_unw_user_mode(info))
-		return -1;
-	while (unwind(info) == 0 && UNW_PC(info)) {
-		n++;
-		oad->ops->address(oad->data, UNW_PC(info));
-		if (arch_unw_user_mode(info))
-			break;
-		if ((sp & ~(PAGE_SIZE - 1)) == (UNW_SP(info) & ~(PAGE_SIZE - 1))
-		    && sp > UNW_SP(info))
-			break;
-		sp = UNW_SP(info);
-	}
-	return n;
-}
-
 #define MSG(txt) ops->warning(data, txt)
 
 /*
@@ -270,40 +239,6 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
 	if (!tsk)
 		tsk = current;
 
-	if (call_trace >= 0) {
-		int unw_ret = 0;
-		struct unwind_frame_info info;
-		struct ops_and_data oad = { .ops = ops, .data = data };
-
-		if (regs) {
-			if (unwind_init_frame_info(&info, tsk, regs) == 0)
-				unw_ret = dump_trace_unwind(&info, &oad);
-		} else if (tsk == current)
-			unw_ret = unwind_init_running(&info, dump_trace_unwind,
-						      &oad);
-		else {
-			if (unwind_init_blocked(&info, tsk) == 0)
-				unw_ret = dump_trace_unwind(&info, &oad);
-		}
-		if (unw_ret > 0) {
-			if (call_trace == 1 && !arch_unw_user_mode(&info)) {
-				ops->warning_symbol(data,
-					     "DWARF2 unwinder stuck at %s",
-					     UNW_PC(&info));
-				if ((long)UNW_SP(&info) < 0) {
-					MSG("Leftover inexact backtrace:");
-					stack = (unsigned long *)UNW_SP(&info);
-					if (!stack)
-						goto out;
-				} else
-					MSG("Full inexact backtrace again:");
-			} else if (call_trace >= 1)
-				goto out;
-			else
-				MSG("Full inexact backtrace again:");
-		} else
-			MSG("Inexact backtrace:");
-	}
 	if (!stack) {
 		unsigned long dummy;
 		stack = &dummy;
@@ -387,7 +322,6 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
 	tinfo = current_thread_info();
 	HANDLE_STACK (valid_stack_ptr(tinfo, stack));
 #undef HANDLE_STACK
-out:
 	put_cpu();
 }
 EXPORT_SYMBOL(dump_trace);
@@ -1188,21 +1122,3 @@ static int __init kstack_setup(char *s)
 	return 0;
 }
 early_param("kstack", kstack_setup);
-
-#ifdef CONFIG_STACK_UNWIND
-static int __init call_trace_setup(char *s)
-{
-	if (!s)
-		return -EINVAL;
-	if (strcmp(s, "old") == 0)
-		call_trace = -1;
-	else if (strcmp(s, "both") == 0)
-		call_trace = 0;
-	else if (strcmp(s, "newfallback") == 0)
-		call_trace = 1;
-	else if (strcmp(s, "new") == 0)
-		call_trace = 2;
-	return 0;
-}
-early_param("call_trace", call_trace_setup);
-#endif
diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S
index 514be5dd230..1e54ddf2338 100644
--- a/arch/x86_64/kernel/vmlinux.lds.S
+++ b/arch/x86_64/kernel/vmlinux.lds.S
@@ -221,9 +221,7 @@ SECTIONS
   /* Sections to be discarded */
   /DISCARD/ : {
 	*(.exitcall.exit)
-#ifndef CONFIG_UNWIND_INFO
 	*(.eh_frame)
-#endif
 	}
 
   STABS_DEBUG
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 7437ccaada7..1587121730c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -119,8 +119,6 @@
 		*(__ksymtab_strings)					\
 	}								\
 									\
-	EH_FRAME							\
-									\
 	/* Built-in module parameters. */				\
 	__param : AT(ADDR(__param) - LOAD_OFFSET) {			\
 		VMLINUX_SYMBOL(__start___param) = .;			\
@@ -160,26 +158,6 @@
 		*(.kprobes.text)					\
 		VMLINUX_SYMBOL(__kprobes_text_end) = .;
 
-#ifdef CONFIG_STACK_UNWIND
-#define EH_FRAME							\
-		/* Unwind data binary search table */			\
-		. = ALIGN(8);						\
-        	.eh_frame_hdr : AT(ADDR(.eh_frame_hdr) - LOAD_OFFSET) {	\
-			VMLINUX_SYMBOL(__start_unwind_hdr) = .;		\
-			*(.eh_frame_hdr)				\
-			VMLINUX_SYMBOL(__end_unwind_hdr) = .;		\
-		}							\
-		/* Unwind data */					\
-		. = ALIGN(8);						\
-		.eh_frame : AT(ADDR(.eh_frame) - LOAD_OFFSET) {		\
-			VMLINUX_SYMBOL(__start_unwind) = .;		\
-		  	*(.eh_frame)					\
-			VMLINUX_SYMBOL(__end_unwind) = .;		\
-		}
-#else
-#define EH_FRAME
-#endif
-
 		/* DWARF debug sections.
 		Symbols in the DWARF debugging sections are relative to
 		the beginning of the section so we begin them at 0.  */
diff --git a/include/asm-i386/unwind.h b/include/asm-i386/unwind.h
index aa2c931e30d..43c70c3de2f 100644
--- a/include/asm-i386/unwind.h
+++ b/include/asm-i386/unwind.h
@@ -1,95 +1,6 @@
 #ifndef _ASM_I386_UNWIND_H
 #define _ASM_I386_UNWIND_H
 
-/*
- * Copyright (C) 2002-2006 Novell, Inc.
- *	Jan Beulich <jbeulich@novell.com>
- * This code is released under version 2 of the GNU GPL.
- */
-
-#ifdef CONFIG_STACK_UNWIND
-
-#include <linux/sched.h>
-#include <asm/fixmap.h>
-#include <asm/ptrace.h>
-#include <asm/uaccess.h>
-
-struct unwind_frame_info
-{
-	struct pt_regs regs;
-	struct task_struct *task;
-	unsigned call_frame:1;
-};
-
-#define UNW_PC(frame)        (frame)->regs.eip
-#define UNW_SP(frame)        (frame)->regs.esp
-#ifdef CONFIG_FRAME_POINTER
-#define UNW_FP(frame)        (frame)->regs.ebp
-#define FRAME_RETADDR_OFFSET 4
-#define FRAME_LINK_OFFSET    0
-#define STACK_BOTTOM(tsk)    STACK_LIMIT((tsk)->thread.esp0)
-#define STACK_TOP(tsk)       ((tsk)->thread.esp0)
-#else
-#define UNW_FP(frame) ((void)(frame), 0)
-#endif
-#define STACK_LIMIT(ptr)     (((ptr) - 1) & ~(THREAD_SIZE - 1))
-
-#define UNW_REGISTER_INFO \
-	PTREGS_INFO(eax), \
-	PTREGS_INFO(ecx), \
-	PTREGS_INFO(edx), \
-	PTREGS_INFO(ebx), \
-	PTREGS_INFO(esp), \
-	PTREGS_INFO(ebp), \
-	PTREGS_INFO(esi), \
-	PTREGS_INFO(edi), \
-	PTREGS_INFO(eip)
-
-#define UNW_DEFAULT_RA(raItem, dataAlign) \
-	((raItem).where == Memory && \
-	 !((raItem).value * (dataAlign) + 4))
-
-static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,
-                                            /*const*/ struct pt_regs *regs)
-{
-	if (user_mode_vm(regs))
-		info->regs = *regs;
-	else {
-		memcpy(&info->regs, regs, offsetof(struct pt_regs, esp));
-		info->regs.esp = (unsigned long)&regs->esp;
-		info->regs.xss = __KERNEL_DS;
-	}
-}
-
-static inline void arch_unw_init_blocked(struct unwind_frame_info *info)
-{
-	memset(&info->regs, 0, sizeof(info->regs));
-	info->regs.eip = info->task->thread.eip;
-	info->regs.xcs = __KERNEL_CS;
-	__get_user(info->regs.ebp, (long *)info->task->thread.esp);
-	info->regs.esp = info->task->thread.esp;
-	info->regs.xss = __KERNEL_DS;
-	info->regs.xds = __USER_DS;
-	info->regs.xes = __USER_DS;
-	info->regs.xgs = __KERNEL_PDA;
-}
-
-extern asmlinkage int arch_unwind_init_running(struct unwind_frame_info *,
-                                               asmlinkage int (*callback)(struct unwind_frame_info *,
-                                                                          void *arg),
-                                               void *arg);
-
-static inline int arch_unw_user_mode(/*const*/ struct unwind_frame_info *info)
-{
-	return user_mode_vm(&info->regs)
-	       || info->regs.eip < PAGE_OFFSET
-	       || (info->regs.eip >= __fix_to_virt(FIX_VDSO)
-	           && info->regs.eip < __fix_to_virt(FIX_VDSO) + PAGE_SIZE)
-	       || info->regs.esp < PAGE_OFFSET;
-}
-
-#else
-
 #define UNW_PC(frame) ((void)(frame), 0)
 #define UNW_SP(frame) ((void)(frame), 0)
 #define UNW_FP(frame) ((void)(frame), 0)
@@ -99,6 +10,4 @@ static inline int arch_unw_user_mode(const void *info)
 	return 0;
 }
 
-#endif
-
 #endif /* _ASM_I386_UNWIND_H */
diff --git a/include/asm-x86_64/unwind.h b/include/asm-x86_64/unwind.h
index 2f6349e4871..02710f6a456 100644
--- a/include/asm-x86_64/unwind.h
+++ b/include/asm-x86_64/unwind.h
@@ -1,100 +1,6 @@
 #ifndef _ASM_X86_64_UNWIND_H
 #define _ASM_X86_64_UNWIND_H
 
-/*
- * Copyright (C) 2002-2006 Novell, Inc.
- *	Jan Beulich <jbeulich@novell.com>
- * This code is released under version 2 of the GNU GPL.
- */
-
-#ifdef CONFIG_STACK_UNWIND
-
-#include <linux/sched.h>
-#include <asm/ptrace.h>
-#include <asm/uaccess.h>
-#include <asm/vsyscall.h>
-
-struct unwind_frame_info
-{
-	struct pt_regs regs;
-	struct task_struct *task;
-	unsigned call_frame:1;
-};
-
-#define UNW_PC(frame)        (frame)->regs.rip
-#define UNW_SP(frame)        (frame)->regs.rsp
-#ifdef CONFIG_FRAME_POINTER
-#define UNW_FP(frame)        (frame)->regs.rbp
-#define FRAME_RETADDR_OFFSET 8
-#define FRAME_LINK_OFFSET    0
-#define STACK_BOTTOM(tsk)    (((tsk)->thread.rsp0 - 1) & ~(THREAD_SIZE - 1))
-#define STACK_TOP(tsk)       ((tsk)->thread.rsp0)
-#endif
-/* Might need to account for the special exception and interrupt handling
-   stacks here, since normally
-	EXCEPTION_STACK_ORDER < THREAD_ORDER < IRQSTACK_ORDER,
-   but the construct is needed only for getting across the stack switch to
-   the interrupt stack - thus considering the IRQ stack itself is unnecessary,
-   and the overhead of comparing against all exception handling stacks seems
-   not desirable. */
-#define STACK_LIMIT(ptr)     (((ptr) - 1) & ~(THREAD_SIZE - 1))
-
-#define UNW_REGISTER_INFO \
-	PTREGS_INFO(rax), \
-	PTREGS_INFO(rdx), \
-	PTREGS_INFO(rcx), \
-	PTREGS_INFO(rbx), \
-	PTREGS_INFO(rsi), \
-	PTREGS_INFO(rdi), \
-	PTREGS_INFO(rbp), \
-	PTREGS_INFO(rsp), \
-	PTREGS_INFO(r8), \
-	PTREGS_INFO(r9), \
-	PTREGS_INFO(r10), \
-	PTREGS_INFO(r11), \
-	PTREGS_INFO(r12), \
-	PTREGS_INFO(r13), \
-	PTREGS_INFO(r14), \
-	PTREGS_INFO(r15), \
-	PTREGS_INFO(rip)
-
-#define UNW_DEFAULT_RA(raItem, dataAlign) \
-	((raItem).where == Memory && \
-	 !((raItem).value * (dataAlign) + 8))
-
-static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,
-                                            /*const*/ struct pt_regs *regs)
-{
-	info->regs = *regs;
-}
-
-static inline void arch_unw_init_blocked(struct unwind_frame_info *info)
-{
-	extern const char thread_return[];
-
-	memset(&info->regs, 0, sizeof(info->regs));
-	info->regs.rip = (unsigned long)thread_return;
-	info->regs.cs = __KERNEL_CS;
-	__get_user(info->regs.rbp, (unsigned long *)info->task->thread.rsp);
-	info->regs.rsp = info->task->thread.rsp;
-	info->regs.ss = __KERNEL_DS;
-}
-
-extern int arch_unwind_init_running(struct unwind_frame_info *,
-                                    int (*callback)(struct unwind_frame_info *,
-                                                    void *arg),
-                                    void *arg);
-
-static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
-{
-	return user_mode(&info->regs)
-	       || (long)info->regs.rip >= 0
-	       || (info->regs.rip >= VSYSCALL_START && info->regs.rip < VSYSCALL_END)
-	       || (long)info->regs.rsp >= 0;
-}
-
-#else
-
 #define UNW_PC(frame) ((void)(frame), 0UL)
 #define UNW_SP(frame) ((void)(frame), 0UL)
 
@@ -103,6 +9,4 @@ static inline int arch_unw_user_mode(const void *info)
 	return 0;
 }
 
-#endif
-
 #endif /* _ASM_X86_64_UNWIND_H */
diff --git a/include/linux/unwind.h b/include/linux/unwind.h
index 749928c161f..7760860fa17 100644
--- a/include/linux/unwind.h
+++ b/include/linux/unwind.h
@@ -14,63 +14,6 @@
 
 struct module;
 
-#ifdef CONFIG_STACK_UNWIND
-
-#include <asm/unwind.h>
-
-#ifndef ARCH_UNWIND_SECTION_NAME
-#define ARCH_UNWIND_SECTION_NAME ".eh_frame"
-#endif
-
-/*
- * Initialize unwind support.
- */
-extern void unwind_init(void);
-extern void unwind_setup(void);
-
-#ifdef CONFIG_MODULES
-
-extern void *unwind_add_table(struct module *,
-                              const void *table_start,
-                              unsigned long table_size);
-
-extern void unwind_remove_table(void *handle, int init_only);
-
-#endif
-
-extern int unwind_init_frame_info(struct unwind_frame_info *,
-                                  struct task_struct *,
-                                  /*const*/ struct pt_regs *);
-
-/*
- * Prepare to unwind a blocked task.
- */
-extern int unwind_init_blocked(struct unwind_frame_info *,
-                               struct task_struct *);
-
-/*
- * Prepare to unwind the currently running thread.
- */
-extern int unwind_init_running(struct unwind_frame_info *,
-                               asmlinkage int (*callback)(struct unwind_frame_info *,
-                                                          void *arg),
-                               void *arg);
-
-/*
- * Unwind to previous to frame.  Returns 0 if successful, negative
- * number in case of an error.
- */
-extern int unwind(struct unwind_frame_info *);
-
-/*
- * Unwind until the return pointer is in user-land (or until an error
- * occurs).  Returns 0 if successful, negative number in case of
- * error.
- */
-extern int unwind_to_user(struct unwind_frame_info *);
-
-#else
-
 struct unwind_frame_info {};
 
 static inline void unwind_init(void) {}
@@ -85,12 +28,12 @@ static inline void *unwind_add_table(struct module *mod,
 	return NULL;
 }
 
-#endif
-
 static inline void unwind_remove_table(void *handle, int init_only)
 {
 }
 
+#endif
+
 static inline int unwind_init_frame_info(struct unwind_frame_info *info,
                                          struct task_struct *tsk,
                                          const struct pt_regs *regs)
@@ -122,6 +65,4 @@ static inline int unwind_to_user(struct unwind_frame_info *info)
 	return -ENOSYS;
 }
 
-#endif
-
 #endif /* _LINUX_UNWIND_H */
diff --git a/kernel/Makefile b/kernel/Makefile
index 5e3f3b75563..14f4d45e0ae 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -31,7 +31,6 @@ obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 obj-$(CONFIG_UID16) += uid16.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
-obj-$(CONFIG_STACK_UNWIND) += unwind.o
 obj-$(CONFIG_PM) += power/
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_KEXEC) += kexec.o
diff --git a/kernel/unwind.c b/kernel/unwind.c
deleted file mode 100644
index 09c26132924..00000000000
--- a/kernel/unwind.c
+++ /dev/null
@@ -1,1305 +0,0 @@
-/*
- * Copyright (C) 2002-2006 Novell, Inc.
- *	Jan Beulich <jbeulich@novell.com>
- * This code is released under version 2 of the GNU GPL.
- *
- * A simple API for unwinding kernel stacks.  This is used for
- * debugging and error reporting purposes.  The kernel doesn't need
- * full-blown stack unwinding with all the bells and whistles, so there
- * is not much point in implementing the full Dwarf2 unwind API.
- */
-
-#include <linux/unwind.h>
-#include <linux/module.h>
-#include <linux/bootmem.h>
-#include <linux/sort.h>
-#include <linux/stop_machine.h>
-#include <linux/uaccess.h>
-#include <asm/sections.h>
-#include <asm/uaccess.h>
-#include <asm/unaligned.h>
-
-extern const char __start_unwind[], __end_unwind[];
-extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];
-
-#define MAX_STACK_DEPTH 8
-
-#define EXTRA_INFO(f) { \
-		BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
-		                  % FIELD_SIZEOF(struct unwind_frame_info, f)) \
-		+ offsetof(struct unwind_frame_info, f) \
-		  / FIELD_SIZEOF(struct unwind_frame_info, f), \
-		FIELD_SIZEOF(struct unwind_frame_info, f) \
-	}
-#define PTREGS_INFO(f) EXTRA_INFO(regs.f)
-
-static const struct {
-	unsigned offs:BITS_PER_LONG / 2;
-	unsigned width:BITS_PER_LONG / 2;
-} reg_info[] = {
-	UNW_REGISTER_INFO
-};
-
-#undef PTREGS_INFO
-#undef EXTRA_INFO
-
-#ifndef REG_INVALID
-#define REG_INVALID(r) (reg_info[r].width == 0)
-#endif
-
-#define DW_CFA_nop                          0x00
-#define DW_CFA_set_loc                      0x01
-#define DW_CFA_advance_loc1                 0x02
-#define DW_CFA_advance_loc2                 0x03
-#define DW_CFA_advance_loc4                 0x04
-#define DW_CFA_offset_extended              0x05
-#define DW_CFA_restore_extended             0x06
-#define DW_CFA_undefined                    0x07
-#define DW_CFA_same_value                   0x08
-#define DW_CFA_register                     0x09
-#define DW_CFA_remember_state               0x0a
-#define DW_CFA_restore_state                0x0b
-#define DW_CFA_def_cfa                      0x0c
-#define DW_CFA_def_cfa_register             0x0d
-#define DW_CFA_def_cfa_offset               0x0e
-#define DW_CFA_def_cfa_expression           0x0f
-#define DW_CFA_expression                   0x10
-#define DW_CFA_offset_extended_sf           0x11
-#define DW_CFA_def_cfa_sf                   0x12
-#define DW_CFA_def_cfa_offset_sf            0x13
-#define DW_CFA_val_offset                   0x14
-#define DW_CFA_val_offset_sf                0x15
-#define DW_CFA_val_expression               0x16
-#define DW_CFA_lo_user                      0x1c
-#define DW_CFA_GNU_window_save              0x2d
-#define DW_CFA_GNU_args_size                0x2e
-#define DW_CFA_GNU_negative_offset_extended 0x2f
-#define DW_CFA_hi_user                      0x3f
-
-#define DW_EH_PE_FORM     0x07
-#define DW_EH_PE_native   0x00
-#define DW_EH_PE_leb128   0x01
-#define DW_EH_PE_data2    0x02
-#define DW_EH_PE_data4    0x03
-#define DW_EH_PE_data8    0x04
-#define DW_EH_PE_signed   0x08
-#define DW_EH_PE_ADJUST   0x70
-#define DW_EH_PE_abs      0x00
-#define DW_EH_PE_pcrel    0x10
-#define DW_EH_PE_textrel  0x20
-#define DW_EH_PE_datarel  0x30
-#define DW_EH_PE_funcrel  0x40
-#define DW_EH_PE_aligned  0x50
-#define DW_EH_PE_indirect 0x80
-#define DW_EH_PE_omit     0xff
-
-typedef unsigned long uleb128_t;
-typedef   signed long sleb128_t;
-#define sleb128abs __builtin_labs
-
-static struct unwind_table {
-	struct {
-		unsigned long pc;
-		unsigned long range;
-	} core, init;
-	const void *address;
-	unsigned long size;
-	const unsigned char *header;
-	unsigned long hdrsz;
-	struct unwind_table *link;
-	const char *name;
-} root_table;
-
-struct unwind_item {
-	enum item_location {
-		Nowhere,
-		Memory,
-		Register,
-		Value
-	} where;
-	uleb128_t value;
-};
-
-struct unwind_state {
-	uleb128_t loc, org;
-	const u8 *cieStart, *cieEnd;
-	uleb128_t codeAlign;
-	sleb128_t dataAlign;
-	struct cfa {
-		uleb128_t reg, offs;
-	} cfa;
-	struct unwind_item regs[ARRAY_SIZE(reg_info)];
-	unsigned stackDepth:8;
-	unsigned version:8;
-	const u8 *label;
-	const u8 *stack[MAX_STACK_DEPTH];
-};
-
-static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
-
-static unsigned unwind_debug;
-static int __init unwind_debug_setup(char *s)
-{
-	unwind_debug = simple_strtoul(s, NULL, 0);
-	return 1;
-}
-__setup("unwind_debug=", unwind_debug_setup);
-#define dprintk(lvl, fmt, args...) \
-	((void)(lvl > unwind_debug \
-	 || printk(KERN_DEBUG "unwind: " fmt "\n", ##args)))
-
-static struct unwind_table *find_table(unsigned long pc)
-{
-	struct unwind_table *table;
-
-	for (table = &root_table; table; table = table->link)
-		if ((pc >= table->core.pc
-		     && pc < table->core.pc + table->core.range)
-		    || (pc >= table->init.pc
-		        && pc < table->init.pc + table->init.range))
-			break;
-
-	return table;
-}
-
-static unsigned long read_pointer(const u8 **pLoc,
-                                  const void *end,
-                                  signed ptrType,
-                                  unsigned long text_base,
-                                  unsigned long data_base);
-
-static void init_unwind_table(struct unwind_table *table,
-                              const char *name,
-                              const void *core_start,
-                              unsigned long core_size,
-                              const void *init_start,
-                              unsigned long init_size,
-                              const void *table_start,
-                              unsigned long table_size,
-                              const u8 *header_start,
-                              unsigned long header_size)
-{
-	const u8 *ptr = header_start + 4;
-	const u8 *end = header_start + header_size;
-
-	table->core.pc = (unsigned long)core_start;
-	table->core.range = core_size;
-	table->init.pc = (unsigned long)init_start;
-	table->init.range = init_size;
-	table->address = table_start;
-	table->size = table_size;
-	/* See if the linker provided table looks valid. */
-	if (header_size <= 4
-	    || header_start[0] != 1
-	    || (void *)read_pointer(&ptr, end, header_start[1], 0, 0)
-	       != table_start
-	    || !read_pointer(&ptr, end, header_start[2], 0, 0)
-	    || !read_pointer(&ptr, end, header_start[3], 0,
-	                     (unsigned long)header_start)
-	    || !read_pointer(&ptr, end, header_start[3], 0,
-	                     (unsigned long)header_start))
-		header_start = NULL;
-	table->hdrsz = header_size;
-	smp_wmb();
-	table->header = header_start;
-	table->link = NULL;
-	table->name = name;
-}
-
-void __init unwind_init(void)
-{
-	init_unwind_table(&root_table, "kernel",
-	                  _text, _end - _text,
-	                  NULL, 0,
-	                  __start_unwind, __end_unwind - __start_unwind,
-	                  __start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);
-}
-
-static const u32 bad_cie, not_fde;
-static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
-static signed fde_pointer_type(const u32 *cie)