Commit 7b956f03 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar

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