x86/debug: Remove perpetually broken, unmaintainable dwarf annotations

So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.

These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.

In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.

So burn down the sick forest, allowing new, healthier growth:

   27 files changed, 350 insertions(+), 1101 deletions(-)

Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:

 - it should be maximally readable, and maximally low-key to
   'ordinary' code reading and maintenance.

 - find a build time method to insert dwarf annotations
   automatically in the most common cases, for pop/push
   instructions that manipulate the stack pointer. This could
   be done for example via a preprocessing step that just
   looks for common patterns - plus special annotations for
   the few cases where we want to depart from the default.
   We have hundreds of CFI annotations, so automating most of
   that makes sense.

 - it should come with build tooling checks that ensure that
   CFI annotations are sensible. We've seen such efforts from
   the framepointer side, and there's no reason it couldn't be
   done on the dwarf side.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 108 insertions, 260 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 1c30976..0ac73de 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -50,7 +50,6 @@
 #include <asm/smp.h>
 #include <asm/page_types.h>
 #include <asm/percpu.h>
-#include <asm/dwarf2.h>
 #include <asm/processor-flags.h>
 #include <asm/ftrace.h>
 #include <asm/irq_vectors.h>
@@ -113,11 +112,10 @@
 
  /* unfortunately push/pop can't be no-op */
 .macro PUSH_GS
-	pushl_cfi $0
+	pushl $0
 .endm
 .macro POP_GS pop=0
 	addl $(4 + \pop), %esp
-	CFI_ADJUST_CFA_OFFSET -(4 + \pop)
 .endm
 .macro POP_GS_EX
 .endm
@@ -137,16 +135,13 @@
 #else	/* CONFIG_X86_32_LAZY_GS */
 
 .macro PUSH_GS
-	pushl_cfi %gs
-	/*CFI_REL_OFFSET gs, 0*/
+	pushl %gs
 .endm
 
 .macro POP_GS pop=0
-98:	popl_cfi %gs
-	/*CFI_RESTORE gs*/
+98:	popl %gs
   .if \pop <> 0
 	add $\pop, %esp
-	CFI_ADJUST_CFA_OFFSET -\pop
   .endif
 .endm
 .macro POP_GS_EX
@@ -170,11 +165,9 @@
 
 .macro GS_TO_REG reg
 	movl %gs, \reg
-	/*CFI_REGISTER gs, \reg*/
 .endm
 .macro REG_TO_PTGS reg
 	movl \reg, PT_GS(%esp)
-	/*CFI_REL_OFFSET gs, PT_GS*/
 .endm
 .macro SET_KERNEL_GS reg
 	movl $(__KERNEL_STACK_CANARY), \reg
@@ -186,26 +179,16 @@
 .macro SAVE_ALL
 	cld
 	PUSH_GS
-	pushl_cfi %fs
-	/*CFI_REL_OFFSET fs, 0;*/
-	pushl_cfi %es
-	/*CFI_REL_OFFSET es, 0;*/
-	pushl_cfi %ds
-	/*CFI_REL_OFFSET ds, 0;*/
-	pushl_cfi %eax
-	CFI_REL_OFFSET eax, 0
-	pushl_cfi %ebp
-	CFI_REL_OFFSET ebp, 0
-	pushl_cfi %edi
-	CFI_REL_OFFSET edi, 0
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %edx
-	CFI_REL_OFFSET edx, 0
-	pushl_cfi %ecx
-	CFI_REL_OFFSET ecx, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl %fs
+	pushl %es
+	pushl %ds
+	pushl %eax
+	pushl %ebp
+	pushl %edi
+	pushl %esi
+	pushl %edx
+	pushl %ecx
+	pushl %ebx
 	movl $(__USER_DS), %edx
 	movl %edx, %ds
 	movl %edx, %es
@@ -215,30 +198,20 @@
 .endm
 
 .macro RESTORE_INT_REGS
-	popl_cfi %ebx
-	CFI_RESTORE ebx
-	popl_cfi %ecx
-	CFI_RESTORE ecx
-	popl_cfi %edx
-	CFI_RESTORE edx
-	popl_cfi %esi
-	CFI_RESTORE esi
-	popl_cfi %edi
-	CFI_RESTORE edi
-	popl_cfi %ebp
-	CFI_RESTORE ebp
-	popl_cfi %eax
-	CFI_RESTORE eax
+	popl %ebx
+	popl %ecx
+	popl %edx
+	popl %esi
+	popl %edi
+	popl %ebp
+	popl %eax
 .endm
 
 .macro RESTORE_REGS pop=0
 	RESTORE_INT_REGS
-1:	popl_cfi %ds
-	/*CFI_RESTORE ds;*/
-2:	popl_cfi %es
-	/*CFI_RESTORE es;*/
-3:	popl_cfi %fs
-	/*CFI_RESTORE fs;*/
+1:	popl %ds
+2:	popl %es
+3:	popl %fs
 	POP_GS \pop
 .pushsection .fixup, "ax"
 4:	movl $0, (%esp)
@@ -254,64 +227,27 @@
 	POP_GS_EX
 .endm
 
-.macro RING0_INT_FRAME
-	CFI_STARTPROC simple
-	CFI_SIGNAL_FRAME
-	CFI_DEF_CFA esp, 3*4
-	/*CFI_OFFSET cs, -2*4;*/
-	CFI_OFFSET eip, -3*4
-.endm
-
-.macro RING0_EC_FRAME
-	CFI_STARTPROC simple
-	CFI_SIGNAL_FRAME
-	CFI_DEF_CFA esp, 4*4
-	/*CFI_OFFSET cs, -2*4;*/
-	CFI_OFFSET eip, -3*4
-.endm
-
-.macro RING0_PTREGS_FRAME
-	CFI_STARTPROC simple
-	CFI_SIGNAL_FRAME
-	CFI_DEF_CFA esp, PT_OLDESP-PT_EBX
-	/*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/
-	CFI_OFFSET eip, PT_EIP-PT_OLDESP
-	/*CFI_OFFSET es, PT_ES-PT_OLDESP;*/
-	/*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/
-	CFI_OFFSET eax, PT_EAX-PT_OLDESP
-	CFI_OFFSET ebp, PT_EBP-PT_OLDESP
-	CFI_OFFSET edi, PT_EDI-PT_OLDESP
-	CFI_OFFSET esi, PT_ESI-PT_OLDESP
-	CFI_OFFSET edx, PT_EDX-PT_OLDESP
-	CFI_OFFSET ecx, PT_ECX-PT_OLDESP
-	CFI_OFFSET ebx, PT_EBX-PT_OLDESP
-.endm
-
 ENTRY(ret_from_fork)
-	CFI_STARTPROC
-	pushl_cfi %eax
+	pushl %eax
 	call schedule_tail
 	GET_THREAD_INFO(%ebp)
-	popl_cfi %eax
-	pushl_cfi $0x0202		# Reset kernel eflags
-	popfl_cfi
+	popl %eax
+	pushl $0x0202		# Reset kernel eflags
+	popfl
 	jmp syscall_exit
-	CFI_ENDPROC
 END(ret_from_fork)
 
 ENTRY(ret_from_kernel_thread)
-	CFI_STARTPROC
-	pushl_cfi %eax
+	pushl %eax
 	call schedule_tail
 	GET_THREAD_INFO(%ebp)
-	popl_cfi %eax
-	pushl_cfi $0x0202		# Reset kernel eflags
-	popfl_cfi
+	popl %eax
+	pushl $0x0202		# Reset kernel eflags
+	popfl
 	movl PT_EBP(%esp),%eax
 	call *PT_EBX(%esp)
 	movl $0,PT_EAX(%esp)
 	jmp syscall_exit
-	CFI_ENDPROC
 ENDPROC(ret_from_kernel_thread)
 
 /*
@@ -323,7 +259,6 @@ ENDPROC(ret_from_kernel_thread)
 
 	# userspace resumption stub bypassing syscall exit tracing
 	ALIGN
-	RING0_PTREGS_FRAME
 ret_from_exception:
 	preempt_stop(CLBR_ANY)
 ret_from_intr:
@@ -367,17 +302,12 @@ need_resched:
 	jmp need_resched
 END(resume_kernel)
 #endif
-	CFI_ENDPROC
 
 /* SYSENTER_RETURN points to after the "sysenter" instruction in
    the vsyscall page.  See vsyscall-sysentry.S, which defines the symbol.  */
 
 	# sysenter call handler stub
 ENTRY(ia32_sysenter_target)
-	CFI_STARTPROC simple
-	CFI_SIGNAL_FRAME
-	CFI_DEF_CFA esp, 0
-	CFI_REGISTER esp, ebp
 	movl TSS_sysenter_sp0(%esp),%esp
 sysenter_past_esp:
 	/*
@@ -385,14 +315,11 @@ sysenter_past_esp:
 	 * enough kernel state to call TRACE_IRQS_OFF can be called - but
 	 * we immediately enable interrupts at that point anyway.
 	 */
-	pushl_cfi $__USER_DS
-	/*CFI_REL_OFFSET ss, 0*/
-	pushl_cfi %ebp
-	CFI_REL_OFFSET esp, 0
-	pushfl_cfi
+	pushl $__USER_DS
+	pushl %ebp
+	pushfl
 	orl $X86_EFLAGS_IF, (%esp)
-	pushl_cfi $__USER_CS
-	/*CFI_REL_OFFSET cs, 0*/
+	pushl $__USER_CS
 	/*
 	 * Push current_thread_info()->sysenter_return to the stack.
 	 * A tiny bit of offset fixup is necessary: TI_sysenter_return
@@ -401,10 +328,9 @@ sysenter_past_esp:
 	 * TOP_OF_KERNEL_STACK_PADDING takes us to the top of the stack;
 	 * and THREAD_SIZE takes us to the bottom.
 	 */
-	pushl_cfi ((TI_sysenter_return) - THREAD_SIZE + TOP_OF_KERNEL_STACK_PADDING + 4*4)(%esp)
-	CFI_REL_OFFSET eip, 0
+	pushl ((TI_sysenter_return) - THREAD_SIZE + TOP_OF_KERNEL_STACK_PADDING + 4*4)(%esp)
 
-	pushl_cfi %eax
+	pushl %eax
 	SAVE_ALL
 	ENABLE_INTERRUPTS(CLBR_NONE)
 
@@ -453,11 +379,11 @@ sysenter_audit:
 	/* movl PT_EAX(%esp), %eax	already set, syscall number: 1st arg to audit */
 	movl PT_EBX(%esp), %edx		/* ebx/a0: 2nd arg to audit */
 	/* movl PT_ECX(%esp), %ecx	already set, a1: 3nd arg to audit */
-	pushl_cfi PT_ESI(%esp)		/* a3: 5th arg */
-	pushl_cfi PT_EDX+4(%esp)	/* a2: 4th arg */
+	pushl PT_ESI(%esp)		/* a3: 5th arg */
+	pushl PT_EDX+4(%esp)	/* a2: 4th arg */
 	call __audit_syscall_entry
-	popl_cfi %ecx /* get that remapped edx off the stack */
-	popl_cfi %ecx /* get that remapped esi off the stack */
+	popl %ecx /* get that remapped edx off the stack */
+	popl %ecx /* get that remapped esi off the stack */
 	movl PT_EAX(%esp),%eax		/* reload syscall number */
 	jmp sysenter_do_call
 
@@ -480,7 +406,6 @@ sysexit_audit:
 	jmp sysenter_exit
 #endif
 
-	CFI_ENDPROC
 .pushsection .fixup,"ax"
 2:	movl $0,PT_FS(%esp)
 	jmp 1b
@@ -491,9 +416,8 @@ ENDPROC(ia32_sysenter_target)
 
 	# system call handler stub
 ENTRY(system_call)
-	RING0_INT_FRAME			# can't unwind into user space anyway
 	ASM_CLAC
-	pushl_cfi %eax			# save orig_eax
+	pushl %eax			# save orig_eax
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
 					# system call tracing in operation / emulation
@@ -527,7 +451,6 @@ restore_all_notrace:
 	movb PT_CS(%esp), %al
 	andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
 	cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
-	CFI_REMEMBER_STATE
 	je ldt_ss			# returning to user-space with LDT SS
 #endif
 restore_nocheck:
@@ -543,7 +466,6 @@ ENTRY(iret_exc)
 	_ASM_EXTABLE(irq_return,iret_exc)
 
 #ifdef CONFIG_X86_ESPFIX32
-	CFI_RESTORE_STATE
 ldt_ss:
 #ifdef CONFIG_PARAVIRT
 	/*
@@ -577,22 +499,19 @@ ldt_ss:
 	shr $16, %edx
 	mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */
 	mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */
-	pushl_cfi $__ESPFIX_SS
-	pushl_cfi %eax			/* new kernel esp */
+	pushl $__ESPFIX_SS
+	pushl %eax			/* new kernel esp */
 	/* Disable interrupts, but do not irqtrace this section: we
 	 * will soon execute iret and the tracer was already set to
 	 * the irqstate after the iret */
 	DISABLE_INTERRUPTS(CLBR_EAX)
 	lss (%esp), %esp		/* switch to espfix segment */
-	CFI_ADJUST_CFA_OFFSET -8
 	jmp restore_nocheck
 #endif
-	CFI_ENDPROC
 ENDPROC(system_call)
 
 	# perform work that needs to be done immediately before resumption
 	ALIGN
-	RING0_PTREGS_FRAME		# can't unwind into user space anyway
 work_pending:
 	testb $_TIF_NEED_RESCHED, %cl
 	jz work_notifysig
@@ -634,9 +553,9 @@ work_notifysig:				# deal with pending signals and
 #ifdef CONFIG_VM86
 	ALIGN
 work_notifysig_v86:
-	pushl_cfi %ecx			# save ti_flags for do_notify_resume
+	pushl %ecx			# save ti_flags for do_notify_resume
 	call save_v86_state		# %eax contains pt_regs pointer
-	popl_cfi %ecx
+	popl %ecx
 	movl %eax, %esp
 	jmp 1b
 #endif
@@ -666,9 +585,7 @@ syscall_exit_work:
 	call syscall_trace_leave
 	jmp resume_userspace
 END(syscall_exit_work)
-	CFI_ENDPROC
 
-	RING0_INT_FRAME			# can't unwind into user space anyway
 syscall_fault:
 	ASM_CLAC
 	GET_THREAD_INFO(%ebp)
@@ -685,7 +602,6 @@ sysenter_badsys:
 	movl $-ENOSYS,%eax
 	jmp sysenter_after_call
 END(sysenter_badsys)
-	CFI_ENDPROC
 
 .macro FIXUP_ESPFIX_STACK
 /*
@@ -701,10 +617,9 @@ END(sysenter_badsys)
 	mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
 	shl $16, %eax
 	addl %esp, %eax			/* the adjusted stack pointer */
-	pushl_cfi $__KERNEL_DS
-	pushl_cfi %eax
+	pushl $__KERNEL_DS
+	pushl %eax
 	lss (%esp), %esp		/* switch to the normal stack segment */
-	CFI_ADJUST_CFA_OFFSET -8
 #endif
 .endm
 .macro UNWIND_ESPFIX_STACK
@@ -728,13 +643,11 @@ END(sysenter_badsys)
  */
 	.align 8
 ENTRY(irq_entries_start)
-	RING0_INT_FRAME
     vector=FIRST_EXTERNAL_VECTOR
     .rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
-	pushl_cfi $(~vector+0x80)	/* Note: always in signed byte range */
+	pushl $(~vector+0x80)	/* Note: always in signed byte range */
     vector=vector+1
 	jmp	common_interrupt
-	CFI_ADJUST_CFA_OFFSET -4
 	.align	8
     .endr
 END(irq_entries_start)
@@ -753,19 +666,16 @@ common_interrupt:
 	call do_IRQ
 	jmp ret_from_intr
 ENDPROC(common_interrupt)
-	CFI_ENDPROC
 
 #define BUILD_INTERRUPT3(name, nr, fn)	\
 ENTRY(name)				\
-	RING0_INT_FRAME;		\
 	ASM_CLAC;			\
-	pushl_cfi $~(nr);		\
+	pushl $~(nr);		\
 	SAVE_ALL;			\
 	TRACE_IRQS_OFF			\
 	movl %esp,%eax;			\
 	call fn;			\
 	jmp ret_from_intr;		\
-	CFI_ENDPROC;			\
 ENDPROC(name)
 
 
@@ -784,37 +694,31 @@ ENDPROC(name)
 #include <asm/entry_arch.h>
 
 ENTRY(coprocessor_error)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi $do_coprocessor_error
+	pushl $0
+	pushl $do_coprocessor_error
 	jmp error_code
-	CFI_ENDPROC
 END(coprocessor_error)
 
 ENTRY(simd_coprocessor_error)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
+	pushl $0
 #ifdef CONFIG_X86_INVD_BUG
 	/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
-	ALTERNATIVE "pushl_cfi $do_general_protection",	\
+	ALTERNATIVE "pushl $do_general_protection",	\
 		    "pushl $do_simd_coprocessor_error", \
 		    X86_FEATURE_XMM
 #else
-	pushl_cfi $do_simd_coprocessor_error
+	pushl $do_simd_coprocessor_error
 #endif
 	jmp error_code
-	CFI_ENDPROC
 END(simd_coprocessor_error)
 
 ENTRY(device_not_available)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $-1			# mark this as an int
-	pushl_cfi $do_device_not_available
+	pushl $-1			# mark this as an int
+	pushl $do_device_not_available
 	jmp error_code
-	CFI_ENDPROC
 END(device_not_available)
 
 #ifdef CONFIG_PARAVIRT
@@ -830,115 +734,89 @@ END(native_irq_enable_sysexit)
 #endif
 
 ENTRY(overflow)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi $do_overflow
+	pushl $0
+	pushl $do_overflow
 	jmp error_code
-	CFI_ENDPROC
 END(overflow)
 
 ENTRY(bounds)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi $do_bounds
+	pushl $0
+	pushl $do_bounds
 	jmp error_code
-	CFI_ENDPROC
 END(bounds)
 
 ENTRY(invalid_op)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi $do_invalid_op
+	pushl $0
+	pushl $do_invalid_op
 	jmp error_code
-	CFI_ENDPROC
 END(invalid_op)
 
 ENTRY(coprocessor_segment_overrun)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi $do_coprocessor_segment_overrun
+	pushl $0
+	pushl $do_coprocessor_segment_overrun
 	jmp error_code
-	CFI_ENDPROC
 END(coprocessor_segment_overrun)
 
 ENTRY(invalid_TSS)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $do_invalid_TSS
+	pushl $do_invalid_TSS
 	jmp error_code
-	CFI_ENDPROC
 END(invalid_TSS)
 
 ENTRY(segment_not_present)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $do_segment_not_present
+	pushl $do_segment_not_present
 	jmp error_code
-	CFI_ENDPROC
 END(segment_not_present)
 
 ENTRY(stack_segment)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $do_stack_segment
+	pushl $do_stack_segment
 	jmp error_code
-	CFI_ENDPROC
 END(stack_segment)
 
 ENTRY(alignment_check)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $do_alignment_check
+	pushl $do_alignment_check
 	jmp error_code
-	CFI_ENDPROC
 END(alignment_check)
 
 ENTRY(divide_error)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0			# no error code
-	pushl_cfi $do_divide_error
+	pushl $0			# no error code
+	pushl $do_divide_error
 	jmp error_code
-	CFI_ENDPROC
 END(divide_error)
 
 #ifdef CONFIG_X86_MCE
 ENTRY(machine_check)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi machine_check_vector
+	pushl $0
+	pushl machine_check_vector
 	jmp error_code
-	CFI_ENDPROC
 END(machine_check)
 #endif
 
 ENTRY(spurious_interrupt_bug)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $0
-	pushl_cfi $do_spurious_interrupt_bug
+	pushl $0
+	pushl $do_spurious_interrupt_bug
 	jmp error_code
-	CFI_ENDPROC
 END(spurious_interrupt_bug)
 
 #ifdef CONFIG_XEN
 /* Xen doesn't set %esp to be precisely what the normal sysenter
    entrypoint expects, so fix it up before using the normal path. */
 ENTRY(xen_sysenter_target)
-	RING0_INT_FRAME
 	addl $5*4, %esp		/* remove xen-provided frame */
-	CFI_ADJUST_CFA_OFFSET -5*4
 	jmp sysenter_past_esp
-	CFI_ENDPROC
 
 ENTRY(xen_hypervisor_callback)
-	CFI_STARTPROC
-	pushl_cfi $-1 /* orig_ax = -1 => not a system call */
+	pushl $-1 /* orig_ax = -1 => not a system call */
 	SAVE_ALL
 	TRACE_IRQS_OFF
 
@@ -962,7 +840,6 @@ ENTRY(xen_do_upcall)
 	call xen_maybe_preempt_hcall
 #endif
 	jmp  ret_from_intr
-	CFI_ENDPROC
 ENDPROC(xen_hypervisor_callback)
 
 # Hypervisor uses this for application faults while it executes.
@@ -976,8 +853,7 @@ ENDPROC(xen_hypervisor_callback)
 # to pop the stack frame we end up in an infinite loop of failsafe callbacks.
 # We distinguish between categories by maintaining a status value in EAX.
 ENTRY(xen_failsafe_callback)
-	CFI_STARTPROC
-	pushl_cfi %eax
+	pushl %eax
 	movl $1,%eax
 1:	mov 4(%esp),%ds
 2:	mov 8(%esp),%es
@@ -986,15 +862,13 @@ ENTRY(xen_failsafe_callback)
 	/* EAX == 0 => Category 1 (Bad segment)
 	   EAX != 0 => Category 2 (Bad IRET) */
 	testl %eax,%eax
-	popl_cfi %eax
+	popl %eax
 	lea 16(%esp),%esp
-	CFI_ADJUST_CFA_OFFSET -16
 	jz 5f
 	jmp iret_exc
-5:	pushl_cfi $-1 /* orig_ax = -1 => not a system call */
+5:	pushl $-1 /* orig_ax = -1 => not a system call */
 	SAVE_ALL
 	jmp ret_from_exception
-	CFI_ENDPROC
 
 .section .fixup,"ax"
 6:	xorl %eax,%eax
@@ -1195,34 +1069,28 @@ return_to_handler:
 
 #ifdef CONFIG_TRACING
 ENTRY(trace_page_fault)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $trace_do_page_fault
+	pushl $trace_do_page_fault
 	jmp error_code
-	CFI_ENDPROC
 END(trace_page_fault)
 #endif
 
 ENTRY(page_fault)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $do_page_fault
+	pushl $do_page_fault
 	ALIGN
 error_code:
 	/* the function address is in %gs's slot on the stack */
-	pushl_cfi %fs
-	/*CFI_REL_OFFSET fs, 0*/
-	pushl_cfi %es
-	/*CFI_REL_OFFSET es, 0*/
-	pushl_cfi %ds
-	/*CFI_REL_OFFSET ds, 0*/
-	pushl_cfi_reg eax
-	pushl_cfi_reg ebp
-	pushl_cfi_reg edi
-	pushl_cfi_reg esi
-	pushl_cfi_reg edx
-	pushl_cfi_reg ecx
-	pushl_cfi_reg ebx
+	pushl %fs
+	pushl %es
+	pushl %ds
+	pushl %eax
+	pushl %ebp
+	pushl %edi
+	pushl %esi
+	pushl %edx
+	pushl %ecx
+	pushl %ebx
 	cld
 	movl $(__KERNEL_PERCPU), %ecx
 	movl %ecx, %fs
@@ -1240,7 +1108,6 @@ error_code:
 	movl %esp,%eax			# pt_regs pointer
 	call *%edi
 	jmp ret_from_exception
-	CFI_ENDPROC
 END(page_fault)
 
 /*
@@ -1261,29 +1128,24 @@ END(page_fault)
 	jne \ok
 \label:
 	movl TSS_sysenter_sp0 + \offset(%esp), %esp
-	CFI_DEF_CFA esp, 0
-	CFI_UNDEFINED eip
-	pushfl_cfi
-	pushl_cfi $__KERNEL_CS
-	pushl_cfi $sysenter_past_esp
-	CFI_REL_OFFSET eip, 0
+	pushfl
+	pushl $__KERNEL_CS
+	pushl $sysenter_past_esp
 .endm
 
 ENTRY(debug)
-	RING0_INT_FRAME
 	ASM_CLAC
 	cmpl $ia32_sysenter_target,(%esp)
 	jne debug_stack_correct
 	FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
 debug_stack_correct:
-	pushl_cfi $-1			# mark this as an int
+	pushl $-1			# mark this as an int
 	SAVE_ALL
 	TRACE_IRQS_OFF
 	xorl %edx,%edx			# error code 0
 	movl %esp,%eax			# pt_regs pointer
 	call do_debug
 	jmp ret_from_exception
-	CFI_ENDPROC
 END(debug)
 
 /*
@@ -1295,45 +1157,40 @@ END(debug)
  * fault happened on the sysenter path.
  */
 ENTRY(nmi)
-	RING0_INT_FRAME
 	ASM_CLAC
 #ifdef CONFIG_X86_ESPFIX32
-	pushl_cfi %eax
+	pushl %eax
 	movl %ss, %eax
 	cmpw $__ESPFIX_SS, %ax
-	popl_cfi %eax
+	popl %eax
 	je nmi_espfix_stack
 #endif
 	cmpl $ia32_sysenter_target,(%esp)
 	je nmi_stack_fixup
-	pushl_cfi %eax
+	pushl %eax
 	movl %esp,%eax
 	/* Do not access memory above the end of our stack page,
 	 * it might not exist.
 	 */
 	andl $(THREAD_SIZE-1),%eax
 	cmpl $(THREAD_SIZE-20),%eax
-	popl_cfi %eax
+	popl %eax
 	jae nmi_stack_correct
 	cmpl $ia32_sysenter_target,12(%esp)
 	je nmi_debug_stack_check
 nmi_stack_correct:
-	/* We have a RING0_INT_FRAME here */
-	pushl_cfi %eax
+	pushl %eax
 	SAVE_ALL
 	xorl %edx,%edx		# zero error code
 	movl %esp,%eax		# pt_regs pointer
 	call do_nmi
 	jmp restore_all_notrace
-	CFI_ENDPROC
 
 nmi_stack_fixup:
-	RING0_INT_FRAME
 	FIX_STACK 12, nmi_stack_correct, 1
 	jmp nmi_stack_correct
 
 nmi_debug_stack_check:
-	/* We have a RING0_INT_FRAME here */
 	cmpw $__KERNEL_CS,16(%esp)
 	jne nmi_stack_correct
 	cmpl $debug,(%esp)
@@ -1345,57 +1202,48 @@ nmi_debug_stack_check:
 
 #ifdef CONFIG_X86_ESPFIX32
 nmi_espfix_stack:
-	/* We have a RING0_INT_FRAME here.
-	 *
+	/*
 	 * create the pointer to lss back
 	 */
-	pushl_cfi %ss
-	pushl_cfi %esp
+	pushl %ss
+	pushl %esp
 	addl $4, (%esp)
 	/* copy the iret frame of 12 bytes */
 	.rept 3
-	pushl_cfi 16(%esp)
+	pushl 16(%esp)
 	.endr
-	pushl_cfi %eax
+	pushl %eax
 	SAVE_ALL
 	FIXUP_ESPFIX_STACK		# %eax == %esp
 	xorl %edx,%edx			# zero error code
 	call do_nmi
 	RESTORE_REGS
 	lss 12+4(%esp), %esp		# back to espfix stack
-	CFI_ADJUST_CFA_OFFSET -24
 	jmp irq_return
 #endif
-	CFI_ENDPROC
 END(nmi)
 
 ENTRY(int3)
-	RING0_INT_FRAME
 	ASM_CLAC
-	pushl_cfi $-1			# mark this as an int
+	pushl $-1			# mark this as an int
 	SAVE_ALL
 	TRACE_IRQS_OFF
 	xorl %edx,%edx		# zero error code
 	movl %esp,%eax		# pt_regs pointer
 	call do_int3
 	jmp ret_from_exception
-	CFI_ENDPROC
 END(int3)
 
 ENTRY(general_protection)
-	RING0_EC_FRAME
-	pushl_cfi $do_general_protection
+	pushl $do_general_protection
 	jmp error_code
-	CFI_ENDPROC
 END(general_protection)
 
 #ifdef CONFIG_KVM_GUEST
 ENTRY(async_page_fault)
-	RING0_EC_FRAME
 	ASM_CLAC
-	pushl_cfi $do_async_page_fault
+	pushl $do_async_page_fault
 	jmp error_code
-	CFI_ENDPROC
 END(async_page_fault)
 #endif