[thirdparty/glibc.git] / sysdeps / aarch64 / sysdep.h

/* 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 */
Commit	Line	Data
6d7e8eda	1	/* Copyright (C) 1997-2023 Free Software Foundation, Inc.
554066b8 MS	2
	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public License as
	7	published by the Free Software Foundation; either version 2.1 of the
	8	License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, see
5a82c748	17	<https://www.gnu.org/licenses/>. */
554066b8	18
389d1f1b SE	19	#ifndef _AARCH64_SYSDEP_H
	20	#define _AARCH64_SYSDEP_H
	21
554066b8 MS	22	#include <sysdeps/generic/sysdep.h>
554066b8 MS	23
389d1f1b SE	24	#ifdef __LP64__
	25	# define AARCH64_R(NAME) R_AARCH64_ ## NAME
	26	# define PTR_REG(n) x##n
	27	# define PTR_LOG_SIZE 3
45b1e17e SN	28	# define PTR_ARG(n)
45b1e17e SN	29	# define SIZE_ARG(n)
389d1f1b SE	30	#else
	31	# define AARCH64_R(NAME) R_AARCH64_P32_ ## NAME
	32	# define PTR_REG(n) w##n
	33	# define PTR_LOG_SIZE 2
45b1e17e SN	34	# define PTR_ARG(n) mov w##n, w##n
45b1e17e SN	35	# define SIZE_ARG(n) mov w##n, w##n
389d1f1b SE	36	#endif
	37
	38	#define PTR_SIZE (1<<PTR_LOG_SIZE)
	39
c9476771 SN	40	#ifndef __ASSEMBLER__
	41	/* Strip pointer authentication code from pointer p. */
	42	static inline void *
	43	strip_pac (void *p)
	44	{
	45	register void *ra asm ("x30") = (p);
	46	asm ("hint 7 // xpaclri" : "+r"(ra));
	47	return ra;
	48	}
d174ec24 SN	49
	50	/* This is needed when glibc is built with -mbranch-protection=pac-ret
	51	with a gcc that is affected by PR target/94891. */
	52	# if HAVE_AARCH64_PAC_RET
	53	# undef RETURN_ADDRESS
	54	# define RETURN_ADDRESS(n) strip_pac (__builtin_return_address (n))
	55	# endif
c9476771 SN	56	#endif
c9476771 SN	57
554066b8 MS	58	#ifdef __ASSEMBLER__
	59
	60	/* Syntactic details of assembler. */
	61
	62	#define ASM_SIZE_DIRECTIVE(name) .size name,.-name
	63
91181954	64	/* Branch Target Identitication support. */
bd4317fb NT	65	#if HAVE_AARCH64_BTI
	66	# define BTI_C hint 34
	67	# define BTI_J hint 36
	68	#else
	69	# define BTI_C nop
	70	# define BTI_J nop
	71	#endif
91181954	72
1be3d6eb SN	73	/* Return address signing support (pac-ret). */
	74	#define PACIASP hint 25
	75	#define AUTIASP hint 29
	76
91181954 SD	77	/* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code. */
	78	#define FEATURE_1_AND 0xc0000000
	79	#define FEATURE_1_BTI 1
	80	#define FEATURE_1_PAC 2
	81
	82	/* Add a NT_GNU_PROPERTY_TYPE_0 note. */
	83	#define GNU_PROPERTY(type, value) \
	84	.section .note.gnu.property, "a"; \
	85	.p2align 3; \
	86	.word 4; \
	87	.word 16; \
	88	.word 5; \
	89	.asciz "GNU"; \
	90	.word type; \
	91	.word 4; \
	92	.word value; \
	93	.word 0; \
	94	.text
	95
	96	/* Add GNU property note with the supported features to all asm code
	97	where sysdep.h is included. */
1be3d6eb SN	98	#if HAVE_AARCH64_BTI && HAVE_AARCH64_PAC_RET
	99	GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI\|FEATURE_1_PAC)
	100	#elif HAVE_AARCH64_BTI
91181954 SD	101	GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI)
	102	#endif
	103
554066b8	104	/* Define an entry point visible from C. */
62216a0a MS	105	#define ENTRY(name) \
	106	.globl C_SYMBOL_NAME(name); \
	107	.type C_SYMBOL_NAME(name),%function; \
34f0d01d	108	.p2align 6; \
62216a0a MS	109	C_LABEL(name) \
62216a0a MS	110	cfi_startproc; \
91181954	111	BTI_C; \
554066b8 MS	112	CALL_MCOUNT
554066b8 MS	113
14d941e4 MS	114	/* Define an entry point visible from C. */
	115	#define ENTRY_ALIGN(name, align) \
	116	.globl C_SYMBOL_NAME(name); \
	117	.type C_SYMBOL_NAME(name),%function; \
	118	.p2align align; \
	119	C_LABEL(name) \
	120	cfi_startproc; \
91181954	121	BTI_C; \
14d941e4 MS	122	CALL_MCOUNT
14d941e4 MS	123
4499bb3e MS	124	/* Define an entry point visible from C with a specified alignment and
	125	pre-padding with NOPs. This can be used to ensure that a critical
	126	loop within a function is cache line aligned. Note this version
	127	does not adjust the padding if CALL_MCOUNT is defined. */
	128
	129	#define ENTRY_ALIGN_AND_PAD(name, align, padding) \
	130	.globl C_SYMBOL_NAME(name); \
	131	.type C_SYMBOL_NAME(name),%function; \
	132	.p2align align; \
91181954	133	.rep padding - 1; /* -1 for bti c. */ \
4499bb3e MS	134	nop; \
	135	.endr; \
	136	C_LABEL(name) \
	137	cfi_startproc; \
91181954	138	BTI_C; \
4499bb3e MS	139	CALL_MCOUNT
4499bb3e MS	140
554066b8	141	#undef END
62216a0a MS	142	#define END(name) \
62216a0a MS	143	cfi_endproc; \
554066b8 MS	144	ASM_SIZE_DIRECTIVE(name)
	145
	146	/* If compiled for profiling, call `mcount' at the start of each function. */
	147	#ifdef PROF
62216a0a	148	# define CALL_MCOUNT \
efbe665c SN	149	str x30, [sp, #-80]!; \
	150	cfi_adjust_cfa_offset (80); \
	151	cfi_rel_offset (x30, 0); \
	152	stp x0, x1, [sp, #16]; \
	153	cfi_rel_offset (x0, 16); \
	154	cfi_rel_offset (x1, 24); \
	155	stp x2, x3, [sp, #32]; \
	156	cfi_rel_offset (x2, 32); \
	157	cfi_rel_offset (x3, 40); \
	158	stp x4, x5, [sp, #48]; \
	159	cfi_rel_offset (x4, 48); \
	160	cfi_rel_offset (x5, 56); \
	161	stp x6, x7, [sp, #64]; \
	162	cfi_rel_offset (x6, 64); \
	163	cfi_rel_offset (x7, 72); \
	164	mov x0, x30; \
62216a0a	165	bl mcount; \
efbe665c SN	166	ldp x0, x1, [sp, #16]; \
	167	cfi_restore (x0); \
	168	cfi_restore (x1); \
	169	ldp x2, x3, [sp, #32]; \
	170	cfi_restore (x2); \
	171	cfi_restore (x3); \
	172	ldp x4, x5, [sp, #48]; \
	173	cfi_restore (x4); \
	174	cfi_restore (x5); \
	175	ldp x6, x7, [sp, #64]; \
	176	cfi_restore (x6); \
	177	cfi_restore (x7); \
	178	ldr x30, [sp], #80; \
	179	cfi_adjust_cfa_offset (-80); \
	180	cfi_restore (x30);
554066b8 MS	181	#else
	182	# define CALL_MCOUNT /* Do nothing. */
	183	#endif
	184
	185	/* Local label name for asm code. */
	186	#ifndef L
	187	# define L(name) .L##name
	188	#endif
	189
389d1f1b SE	190	/* Load or store to/from a pc-relative EXPR into/from R, using T.
	191	Note R and T are register numbers and not register names. */
	192	#define LDST_PCREL(OP, R, T, EXPR) \
	193	adrp x##T, EXPR; \
	194	OP PTR_REG (R), [x##T, #:lo12:EXPR]; \
9188b681	195
389d1f1b SE	196	/* Load or store to/from a got-relative EXPR into/from R, using T.
	197	Note R and T are register numbers and not register names. */
	198	#define LDST_GLOBAL(OP, R, T, EXPR) \
	199	adrp x##T, :got:EXPR; \
	200	ldr PTR_REG (T), [x##T, #:got_lo12:EXPR]; \
	201	OP PTR_REG (R), [x##T];
9188b681	202
6cd380dd WB	203	/* Load an immediate into R.
	204	Note R is a register number and not a register name. */
	205	#ifdef __LP64__
	206	# define MOVL(R, NAME) \
	207	movz PTR_REG (R), #:abs_g3:NAME; \
	208	movk PTR_REG (R), #:abs_g2_nc:NAME; \
	209	movk PTR_REG (R), #:abs_g1_nc:NAME; \
	210	movk PTR_REG (R), #:abs_g0_nc:NAME;
	211	#else
	212	# define MOVL(R, NAME) \
	213	movz PTR_REG (R), #:abs_g1:NAME; \
	214	movk PTR_REG (R), #:abs_g0_nc:NAME;
	215	#endif
	216
554066b8 MS	217	/* Since C identifiers are not normally prefixed with an underscore
	218	on this system, the asm identifier `syscall_error' intrudes on the
	219	C name space. Make sure we use an innocuous name. */
	220	#define syscall_error __syscall_error
	221	#define mcount _mcount
	222
	223	#endif /* __ASSEMBLER__ */
389d1f1b SE	224
389d1f1b SE	225	#endif /* _AARCH64_SYSDEP_H */