linux/arch/x86/include/asm/dwarf2.h
Arvind Sankar 6f8f0dc980 x86/vmlinux: Drop unneeded linker script discard of .eh_frame
Now that .eh_frame sections for the files in setup.elf and realmode.elf
are not generated anymore, the linker scripts don't need the special
output section name /DISCARD/ any more.

Remove the one in the main kernel linker script as well, since there are
no .eh_frame sections already, and fix up a comment referencing .eh_frame.

Update the comment in asm/dwarf2.h referring to .eh_frame so it continues
to make sense, as well as being more specific.

 [ bp: Touch up commit message. ]

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20200224232129.597160-3-nivedita@alum.mit.edu
2020-02-25 14:51:29 +01:00

86 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#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__)
#ifndef BUILD_VDSO
/*
* 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 we
* ever decide to enable DWARF unwinding at runtime.
*/
.cfi_sections .debug_frame
#else
/*
* For the vDSO, emit both runtime unwind information and debug
* symbols for the .dbg file.
*/
.cfi_sections .eh_frame, .debug_frame
#endif
#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
#endif /* _ASM_X86_DWARF2_H */