Commit 7b956f03 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86/asm: Re-add parts of the manual CFI infrastructure 



Commit:

  131484c8 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations")

removed all the manual DWARF annotations outside the vDSO.  It also removed
the macros we used for the manual annotations.

Re-add these macros so that we can clean up the vDSO annotations.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
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: H. Peter Anvin <hpa@zytor.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
Link: http://lkml.kernel.org/r/4c70bb98a8b773c8ccfaabf6745e569ff43e7f65.1444091584.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 0a6d1fa0

arch/x86/Makefile

+8 −2
Original line number Diff line number Diff line
@@ -159,6 +159,12 @@ endif 
sp-$(CONFIG_X86_32) := esp

sp-$(CONFIG_X86_64) := rsp



# do binutils support CFI?

cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)

# is .cfi_signal_frame supported too?

cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)

cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)



# does binutils support specific instructions?

asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)

asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
@@ -166,8 +172,8 @@ asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1) 
avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)

avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)



KBUILD_AFLAGS += $(asinstr) $(avx_instr) $(avx2_instr)

KBUILD_CFLAGS += $(asinstr) $(avx_instr) $(avx2_instr)

KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr)

KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr)



LDFLAGS := -m elf_$(UTS_MACHINE)

arch/x86/include/asm/dwarf2.h

0 → 100644
+170 −0
Original line number Diff line number Diff line 
#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

#define CFI_ESCAPE		.cfi_escape



#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_ESCAPE		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 pushq_cfi_reg reg

	pushq %\reg

	CFI_ADJUST_CFA_OFFSET 8

	CFI_REL_OFFSET \reg, 0

	.endm



	.macro popq_cfi reg

	popq \reg

	CFI_ADJUST_CFA_OFFSET -8

	.endm



	.macro popq_cfi_reg reg

	popq %\reg

	CFI_ADJUST_CFA_OFFSET -8

	CFI_RESTORE \reg

	.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 pushl_cfi_reg reg

	pushl %\reg

	CFI_ADJUST_CFA_OFFSET 4

	CFI_REL_OFFSET \reg, 0

	.endm



	.macro popl_cfi reg

	popl \reg

	CFI_ADJUST_CFA_OFFSET -4

	.endm



	.macro popl_cfi_reg reg

	popl %\reg

	CFI_ADJUST_CFA_OFFSET -4

	CFI_RESTORE \reg

	.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 */

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