glibc/sysdeps/aarch64/sysdep.h

226 lines
6.3 KiB
C

/* Copyright (C) 1997-2023 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 _AARCH64_SYSDEP_H
#define _AARCH64_SYSDEP_H
#include <sysdeps/generic/sysdep.h>
#ifdef __LP64__
# define AARCH64_R(NAME) R_AARCH64_ ## NAME
# define PTR_REG(n) x##n
# define PTR_LOG_SIZE 3
# define PTR_ARG(n)
# define SIZE_ARG(n)
#else
# define AARCH64_R(NAME) R_AARCH64_P32_ ## NAME
# define PTR_REG(n) w##n
# define PTR_LOG_SIZE 2
# define PTR_ARG(n) mov w##n, w##n
# define SIZE_ARG(n) mov w##n, w##n
#endif
#define PTR_SIZE (1<<PTR_LOG_SIZE)
#ifndef __ASSEMBLER__
/* Strip pointer authentication code from pointer p. */
static inline void *
strip_pac (void *p)
{
register void *ra asm ("x30") = (p);
asm ("hint 7 // xpaclri" : "+r"(ra));
return ra;
}
/* This is needed when glibc is built with -mbranch-protection=pac-ret
with a gcc that is affected by PR target/94891. */
# if HAVE_AARCH64_PAC_RET
# undef RETURN_ADDRESS
# define RETURN_ADDRESS(n) strip_pac (__builtin_return_address (n))
# endif
#endif
#ifdef __ASSEMBLER__
/* Syntactic details of assembler. */
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name
/* Branch Target Identitication support. */
#if HAVE_AARCH64_BTI
# define BTI_C hint 34
# define BTI_J hint 36
#else
# define BTI_C nop
# define BTI_J nop
#endif
/* Return address signing support (pac-ret). */
#define PACIASP hint 25
#define AUTIASP hint 29
/* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code. */
#define FEATURE_1_AND 0xc0000000
#define FEATURE_1_BTI 1
#define FEATURE_1_PAC 2
/* Add a NT_GNU_PROPERTY_TYPE_0 note. */
#define GNU_PROPERTY(type, value) \
.section .note.gnu.property, "a"; \
.p2align 3; \
.word 4; \
.word 16; \
.word 5; \
.asciz "GNU"; \
.word type; \
.word 4; \
.word value; \
.word 0; \
.text
/* Add GNU property note with the supported features to all asm code
where sysdep.h is included. */
#if HAVE_AARCH64_BTI && HAVE_AARCH64_PAC_RET
GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC)
#elif HAVE_AARCH64_BTI
GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI)
#endif
/* Define an entry point visible from C. */
#define ENTRY(name) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),%function; \
.p2align 6; \
C_LABEL(name) \
cfi_startproc; \
BTI_C; \
CALL_MCOUNT
/* Define an entry point visible from C. */
#define ENTRY_ALIGN(name, align) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),%function; \
.p2align align; \
C_LABEL(name) \
cfi_startproc; \
BTI_C; \
CALL_MCOUNT
/* Define an entry point visible from C with a specified alignment and
pre-padding with NOPs. This can be used to ensure that a critical
loop within a function is cache line aligned. Note this version
does not adjust the padding if CALL_MCOUNT is defined. */
#define ENTRY_ALIGN_AND_PAD(name, align, padding) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),%function; \
.p2align align; \
.rep padding - 1; /* -1 for bti c. */ \
nop; \
.endr; \
C_LABEL(name) \
cfi_startproc; \
BTI_C; \
CALL_MCOUNT
#undef END
#define END(name) \
cfi_endproc; \
ASM_SIZE_DIRECTIVE(name)
/* If compiled for profiling, call `mcount' at the start of each function. */
#ifdef PROF
# define CALL_MCOUNT \
str x30, [sp, #-80]!; \
cfi_adjust_cfa_offset (80); \
cfi_rel_offset (x30, 0); \
stp x0, x1, [sp, #16]; \
cfi_rel_offset (x0, 16); \
cfi_rel_offset (x1, 24); \
stp x2, x3, [sp, #32]; \
cfi_rel_offset (x2, 32); \
cfi_rel_offset (x3, 40); \
stp x4, x5, [sp, #48]; \
cfi_rel_offset (x4, 48); \
cfi_rel_offset (x5, 56); \
stp x6, x7, [sp, #64]; \
cfi_rel_offset (x6, 64); \
cfi_rel_offset (x7, 72); \
mov x0, x30; \
bl mcount; \
ldp x0, x1, [sp, #16]; \
cfi_restore (x0); \
cfi_restore (x1); \
ldp x2, x3, [sp, #32]; \
cfi_restore (x2); \
cfi_restore (x3); \
ldp x4, x5, [sp, #48]; \
cfi_restore (x4); \
cfi_restore (x5); \
ldp x6, x7, [sp, #64]; \
cfi_restore (x6); \
cfi_restore (x7); \
ldr x30, [sp], #80; \
cfi_adjust_cfa_offset (-80); \
cfi_restore (x30);
#else
# define CALL_MCOUNT /* Do nothing. */
#endif
/* Local label name for asm code. */
#ifndef L
# define L(name) .L##name
#endif
/* Load or store to/from a pc-relative EXPR into/from R, using T.
Note R and T are register numbers and not register names. */
#define LDST_PCREL(OP, R, T, EXPR) \
adrp x##T, EXPR; \
OP PTR_REG (R), [x##T, #:lo12:EXPR]; \
/* Load or store to/from a got-relative EXPR into/from R, using T.
Note R and T are register numbers and not register names. */
#define LDST_GLOBAL(OP, R, T, EXPR) \
adrp x##T, :got:EXPR; \
ldr PTR_REG (T), [x##T, #:got_lo12:EXPR]; \
OP PTR_REG (R), [x##T];
/* Load an immediate into R.
Note R is a register number and not a register name. */
#ifdef __LP64__
# define MOVL(R, NAME) \
movz PTR_REG (R), #:abs_g3:NAME; \
movk PTR_REG (R), #:abs_g2_nc:NAME; \
movk PTR_REG (R), #:abs_g1_nc:NAME; \
movk PTR_REG (R), #:abs_g0_nc:NAME;
#else
# define MOVL(R, NAME) \
movz PTR_REG (R), #:abs_g1:NAME; \
movk PTR_REG (R), #:abs_g0_nc:NAME;
#endif
/* 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
#endif /* __ASSEMBLER__ */
#endif /* _AARCH64_SYSDEP_H */