linux/arch/x86/include/asm/dwarf2.h
Jan Beulich eab9e6137f x86-64: Fix CFI data for interrupt frames
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>
2011-09-28 19:04:52 +02:00

147 lines
3.4 KiB
C

#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 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 */