The patch titled "x86: Don't use frame pointer to save old stack on irq entry" did not properly adjust CFI directives, so this patch is a follow-up to that one. With the old stack pointer no longer stored in a callee-saved register (plus some offset), we now have to use a CFA expression to describe the memory location where it is being found. This requires the use of .cfi_escape (allowing arbitrary byte streams to be emitted into .eh_frame), as there is no .cfi_def_cfa_expression (which also cannot reasonably be expected, as it would require a full expression parser). Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/4E8360200200007800058467@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
		
			
				
	
	
		
			146 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			146 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _ASM_X86_DWARF2_H
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#define _ASM_X86_DWARF2_H
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#ifndef __ASSEMBLY__
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#warning "asm/dwarf2.h should be only included in pure assembly files"
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#endif
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/*
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 * Macros for dwarf2 CFI unwind table entries.
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 * See "as.info" for details on these pseudo ops. Unfortunately
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 * they are only supported in very new binutils, so define them
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 * away for older version.
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 */
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#ifdef CONFIG_AS_CFI
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#define CFI_STARTPROC		.cfi_startproc
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#define CFI_ENDPROC		.cfi_endproc
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#define CFI_DEF_CFA		.cfi_def_cfa
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#define CFI_DEF_CFA_REGISTER	.cfi_def_cfa_register
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#define CFI_DEF_CFA_OFFSET	.cfi_def_cfa_offset
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#define CFI_ADJUST_CFA_OFFSET	.cfi_adjust_cfa_offset
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#define CFI_OFFSET		.cfi_offset
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#define CFI_REL_OFFSET		.cfi_rel_offset
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#define CFI_REGISTER		.cfi_register
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#define CFI_RESTORE		.cfi_restore
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#define CFI_REMEMBER_STATE	.cfi_remember_state
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#define CFI_RESTORE_STATE	.cfi_restore_state
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#define CFI_UNDEFINED		.cfi_undefined
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#define CFI_ESCAPE		.cfi_escape
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#ifdef CONFIG_AS_CFI_SIGNAL_FRAME
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#define CFI_SIGNAL_FRAME	.cfi_signal_frame
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#else
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#define CFI_SIGNAL_FRAME
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#endif
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#if defined(CONFIG_AS_CFI_SECTIONS) && defined(__ASSEMBLY__)
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	/*
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	 * Emit CFI data in .debug_frame sections, not .eh_frame sections.
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	 * The latter we currently just discard since we don't do DWARF
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	 * unwinding at runtime.  So only the offline DWARF information is
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	 * useful to anyone.  Note we should not use this directive if this
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	 * file is used in the vDSO assembly, or if vmlinux.lds.S gets
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	 * changed so it doesn't discard .eh_frame.
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	 */
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	.cfi_sections .debug_frame
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#endif
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#else
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/*
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 * Due to the structure of pre-exisiting code, don't use assembler line
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 * comment character # to ignore the arguments. Instead, use a dummy macro.
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 */
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.macro cfi_ignore a=0, b=0, c=0, d=0
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.endm
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#define CFI_STARTPROC		cfi_ignore
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#define CFI_ENDPROC		cfi_ignore
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#define CFI_DEF_CFA		cfi_ignore
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#define CFI_DEF_CFA_REGISTER	cfi_ignore
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#define CFI_DEF_CFA_OFFSET	cfi_ignore
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#define CFI_ADJUST_CFA_OFFSET	cfi_ignore
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#define CFI_OFFSET		cfi_ignore
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#define CFI_REL_OFFSET		cfi_ignore
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#define CFI_REGISTER		cfi_ignore
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#define CFI_RESTORE		cfi_ignore
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#define CFI_REMEMBER_STATE	cfi_ignore
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#define CFI_RESTORE_STATE	cfi_ignore
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#define CFI_UNDEFINED		cfi_ignore
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#define CFI_ESCAPE		cfi_ignore
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#define CFI_SIGNAL_FRAME	cfi_ignore
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#endif
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/*
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 * An attempt to make CFI annotations more or less
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 * correct and shorter. It is implied that you know
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 * what you're doing if you use them.
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 */
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#ifdef __ASSEMBLY__
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#ifdef CONFIG_X86_64
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	.macro pushq_cfi reg
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	pushq \reg
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	CFI_ADJUST_CFA_OFFSET 8
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	.endm
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	.macro popq_cfi reg
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	popq \reg
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	CFI_ADJUST_CFA_OFFSET -8
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	.endm
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	.macro pushfq_cfi
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	pushfq
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	CFI_ADJUST_CFA_OFFSET 8
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	.endm
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	.macro popfq_cfi
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	popfq
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	CFI_ADJUST_CFA_OFFSET -8
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	.endm
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	.macro movq_cfi reg offset=0
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	movq %\reg, \offset(%rsp)
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	CFI_REL_OFFSET \reg, \offset
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	.endm
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	.macro movq_cfi_restore offset reg
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	movq \offset(%rsp), %\reg
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	CFI_RESTORE \reg
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	.endm
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#else /*!CONFIG_X86_64*/
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	.macro pushl_cfi reg
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	pushl \reg
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	CFI_ADJUST_CFA_OFFSET 4
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	.endm
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	.macro popl_cfi reg
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	popl \reg
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	CFI_ADJUST_CFA_OFFSET -4
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	.endm
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	.macro pushfl_cfi
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	pushfl
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	CFI_ADJUST_CFA_OFFSET 4
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	.endm
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	.macro popfl_cfi
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	popfl
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	CFI_ADJUST_CFA_OFFSET -4
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	.endm
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	.macro movl_cfi reg offset=0
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	movl %\reg, \offset(%esp)
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	CFI_REL_OFFSET \reg, \offset
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	.endm
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	.macro movl_cfi_restore offset reg
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	movl \offset(%esp), %\reg
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	CFI_RESTORE \reg
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	.endm
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#endif /*!CONFIG_X86_64*/
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#endif /*__ASSEMBLY__*/
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#endif /* _ASM_X86_DWARF2_H */
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