arch/x86/include/asm/dwarf2.h

#ifndef _ASM_X86_DWARF2_H
#define _ASM_X86_DWARF2_H

#ifndef __ASSEMBLY__
#warning "asm/dwarf2.h should be only included in pure assembly files"
#endif

/*
 * Macros for dwarf2 CFI unwind table entries.
 * See "as.info" for details on these pseudo ops. Unfortunately
 * they are only supported in very new binutils, so define them
 * away for older version.
 */

#ifdef CONFIG_AS_CFI

#define CFI_STARTPROC		.cfi_startproc
#define CFI_ENDPROC		.cfi_endproc
#define CFI_DEF_CFA		.cfi_def_cfa
#define CFI_DEF_CFA_REGISTER	.cfi_def_cfa_register
#define CFI_DEF_CFA_OFFSET	.cfi_def_cfa_offset
#define CFI_ADJUST_CFA_OFFSET	.cfi_adjust_cfa_offset
#define CFI_OFFSET		.cfi_offset
#define CFI_REL_OFFSET		.cfi_rel_offset
#define CFI_REGISTER		.cfi_register
#define CFI_RESTORE		.cfi_restore
#define CFI_REMEMBER_STATE	.cfi_remember_state
#define CFI_RESTORE_STATE	.cfi_restore_state
#define CFI_UNDEFINED		.cfi_undefined

#ifdef CONFIG_AS_CFI_SIGNAL_FRAME
#define CFI_SIGNAL_FRAME	.cfi_signal_frame
#else
#define CFI_SIGNAL_FRAME
#endif

#if defined(CONFIG_AS_CFI_SECTIONS) && defined(__ASSEMBLY__)
	/*
	 * Emit CFI data in .debug_frame sections, not .eh_frame sections.
	 * The latter we currently just discard since we don't do DWARF
	 * unwinding at runtime.  So only the offline DWARF information is
	 * useful to anyone.  Note we should not use this directive if this
	 * file is used in the vDSO assembly, or if vmlinux.lds.S gets
	 * changed so it doesn't discard .eh_frame.
	 */
	.cfi_sections .debug_frame
#endif

#else

/*
 * Due to the structure of pre-exisiting code, don't use assembler line
 * comment character # to ignore the arguments. Instead, use a dummy macro.
 */
.macro cfi_ignore a=0, b=0, c=0, d=0
.endm

#define CFI_STARTPROC		cfi_ignore
#define CFI_ENDPROC		cfi_ignore
#define CFI_DEF_CFA		cfi_ignore
#define CFI_DEF_CFA_REGISTER	cfi_ignore
#define CFI_DEF_CFA_OFFSET	cfi_ignore
#define CFI_ADJUST_CFA_OFFSET	cfi_ignore
#define CFI_OFFSET		cfi_ignore
#define CFI_REL_OFFSET		cfi_ignore
#define CFI_REGISTER		cfi_ignore
#define CFI_RESTORE		cfi_ignore
#define CFI_REMEMBER_STATE	cfi_ignore
#define CFI_RESTORE_STATE	cfi_ignore
#define CFI_UNDEFINED		cfi_ignore
#define CFI_SIGNAL_FRAME	cfi_ignore

#endif

/*
 * An attempt to make CFI annotations more or less
 * correct and shorter. It is implied that you know
 * what you're doing if you use them.
 */
#ifdef __ASSEMBLY__
#ifdef CONFIG_X86_64
	.macro pushq_cfi reg
	pushq \reg
	CFI_ADJUST_CFA_OFFSET 8
	.endm

	.macro popq_cfi reg
	popq \reg
	CFI_ADJUST_CFA_OFFSET -8
	.endm

	.macro pushfq_cfi
	pushfq
	CFI_ADJUST_CFA_OFFSET 8
	.endm

	.macro popfq_cfi
	popfq
	CFI_ADJUST_CFA_OFFSET -8
	.endm

	.macro movq_cfi reg offset=0
	movq %\reg, \offset(%rsp)
	CFI_REL_OFFSET \reg, \offset
	.endm

	.macro movq_cfi_restore offset reg
	movq \offset(%rsp), %\reg
	CFI_RESTORE \reg
	.endm
#else /*!CONFIG_X86_64*/
	.macro pushl_cfi reg
	pushl \reg
	CFI_ADJUST_CFA_OFFSET 4
	.endm

	.macro popl_cfi reg
	popl \reg
	CFI_ADJUST_CFA_OFFSET -4
	.endm

	.macro pushfl_cfi
	pushfl
	CFI_ADJUST_CFA_OFFSET 4
	.endm

	.macro popfl_cfi
	popfl
	CFI_ADJUST_CFA_OFFSET -4
	.endm

	.macro movl_cfi reg offset=0
	movl %\reg, \offset(%esp)
	CFI_REL_OFFSET \reg, \offset
	.endm

	.macro movl_cfi_restore offset reg
	movl \offset(%esp), %\reg
	CFI_RESTORE \reg
	.endm
#endif /*!CONFIG_X86_64*/
#endif /*__ASSEMBLY__*/

#endif /* _ASM_X86_DWARF2_H */