glibc/sysdeps/x86/sysdep.h

123 lines
3.5 KiB
C

/* Assembler macros for x86.
Copyright (C) 2017-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _X86_SYSDEP_H
#define _X86_SYSDEP_H 1
#include <sysdeps/generic/sysdep.h>
/* __CET__ is defined by GCC with Control-Flow Protection values:
enum cf_protection_level
{
CF_NONE = 0,
CF_BRANCH = 1 << 0,
CF_RETURN = 1 << 1,
CF_FULL = CF_BRANCH | CF_RETURN,
CF_SET = 1 << 2
};
*/
/* Set if CF_BRANCH (IBT) is enabled. */
#define X86_FEATURE_1_IBT (1U << 0)
/* Set if CF_RETURN (SHSTK) is enabled. */
#define X86_FEATURE_1_SHSTK (1U << 1)
#ifdef __CET__
# define CET_ENABLED 1
# define IBT_ENABLED (__CET__ & X86_FEATURE_1_IBT)
# define SHSTK_ENABLED (__CET__ & X86_FEATURE_1_SHSTK)
#else
# define CET_ENABLED 0
# define IBT_ENABLED 0
# define SHSTK_ENABLED 0
#endif
/* Offset for fxsave/xsave area used by _dl_runtime_resolve. Also need
space to preserve RCX, RDX, RSI, RDI, R8, R9 and RAX. It must be
aligned to 16 bytes for fxsave and 64 bytes for xsave. */
#define STATE_SAVE_OFFSET (8 * 7 + 8)
/* Save SSE, AVX, AVX512, mask and bound registers. */
#define STATE_SAVE_MASK \
((1 << 1) | (1 << 2) | (1 << 3) | (1 << 5) | (1 << 6) | (1 << 7))
/* Constants for bits in __x86_string_control: */
/* Avoid short distance REP MOVSB. */
#define X86_STRING_CONTROL_AVOID_SHORT_DISTANCE_REP_MOVSB (1 << 0)
#ifdef __ASSEMBLER__
/* Syntactic details of assembler. */
#ifdef _CET_ENDBR
# define _CET_NOTRACK notrack
#else
# define _CET_ENDBR
# define _CET_NOTRACK
#endif
/* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
#define ALIGNARG(log2) 1<<log2
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
/* Define an entry point visible from C. */
#define ENTRY_P2ALIGN(name, alignment) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),@function; \
.align ALIGNARG(alignment); \
C_LABEL(name) \
cfi_startproc; \
_CET_ENDBR; \
CALL_MCOUNT
/* Common entry 16 byte aligns. */
#define ENTRY(name) ENTRY_P2ALIGN (name, 4)
#undef END
#define END(name) \
cfi_endproc; \
ASM_SIZE_DIRECTIVE(name)
#define ENTRY_CHK(name) ENTRY (name)
#define END_CHK(name) END (name)
/* Since C identifiers are not normally prefixed with an underscore
on this system, the asm identifier `syscall_error' intrudes on the
C name space. Make sure we use an innocuous name. */
#define syscall_error __syscall_error
#define mcount _mcount
#undef PSEUDO_END
#define PSEUDO_END(name) \
END (name)
/* Local label name for asm code. */
#ifndef L
/* ELF-like local names start with `.L'. */
# define LOCAL_LABEL(name) .L##name
# define L(name) LOCAL_LABEL(name)
#endif
#define atom_text_section .section ".text.atom", "ax"
#endif /* __ASSEMBLER__ */
#endif /* _X86_SYSDEP_H */