08b4716a9e
Add Branch Target Identifiers (BTIs) to all functions defined in AArch64 assembly files. Most of the BTI landing pads are added automatically by the 'function' macro. BTI support is turned on or off at compile time based on the presence of the __ARM_FEATURE_BTI_DEFAULT feature macro. A binary compiled with BTI support can be executed on an Armv8-A processor without BTI support because the instructions are defined in NOP space. Signed-off-by: Jonathan Wright <jonathan.wright@arm.com> Signed-off-by: Elijah Ahmad <elijah.ahmad@arm.com> Signed-off-by: Martin Storsjö <martin@martin.st>
148 lines
3.9 KiB
ArmAsm
148 lines
3.9 KiB
ArmAsm
/*
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* Copyright (c) 2008 Mans Rullgard <mans@mansr.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "config.h"
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#ifdef __ELF__
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# define ELF
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#else
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# define ELF #
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#endif
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#if HAVE_AS_FUNC
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# define FUNC
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#else
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# define FUNC #
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#endif
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#ifndef __has_feature
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# define __has_feature(x) 0
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#endif
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/* Support macros for the Armv8.5-A Branch Target Identification feature which
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* requires emitting a .note.gnu.property section with the appropriate
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* architecture-dependent feature bits set.
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* Read more: "ELF for the Arm® 64-bit Architecture"
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*/
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#if defined(__ARM_FEATURE_BTI_DEFAULT) && (__ARM_FEATURE_BTI_DEFAULT == 1)
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# define GNU_PROPERTY_AARCH64_BTI (1 << 0) // Has BTI
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# define AARCH64_VALID_CALL_TARGET hint #34 // BTI 'c'
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# define AARCH64_VALID_JUMP_TARGET hint #38 // BTI 'j'
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#else
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# define GNU_PROPERTY_AARCH64_BTI 0 // No BTI
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# define AARCH64_VALID_CALL_TARGET
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# define AARCH64_VALID_JUMP_TARGET
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#endif
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#if (GNU_PROPERTY_AARCH64_BTI != 0)
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.pushsection .note.gnu.property, "a"
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.balign 8
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.long 4
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.long 0x10
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.long 0x5
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.asciz "GNU"
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.long 0xc0000000 /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */
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.long 4
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.long GNU_PROPERTY_AARCH64_BTI
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.long 0
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.popsection
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#endif
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.macro function name, export=0, align=2
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.macro endfunc
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ELF .size \name, . - \name
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FUNC .endfunc
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.purgem endfunc
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.endm
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.text
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.align \align
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.if \export
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.global EXTERN_ASM\name
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ELF .type EXTERN_ASM\name, %function
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FUNC .func EXTERN_ASM\name
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EXTERN_ASM\name:
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AARCH64_VALID_CALL_TARGET
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.else
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ELF .type \name, %function
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FUNC .func \name
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\name:
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.endif
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.endm
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.macro const name, align=2, relocate=0
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.macro endconst
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ELF .size \name, . - \name
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.purgem endconst
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.endm
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#if HAVE_SECTION_DATA_REL_RO
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.if \relocate
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.section .data.rel.ro
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.else
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.section .rodata
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.endif
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#elif defined(_WIN32)
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.section .rdata
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#elif !defined(__MACH__)
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.section .rodata
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#else
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.const_data
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#endif
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.align \align
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\name:
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.endm
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.macro movrel rd, val, offset=0
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#if CONFIG_PIC && defined(__APPLE__)
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.if \offset < 0
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adrp \rd, \val@PAGE
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add \rd, \rd, \val@PAGEOFF
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sub \rd, \rd, -(\offset)
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.else
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adrp \rd, \val+(\offset)@PAGE
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add \rd, \rd, \val+(\offset)@PAGEOFF
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.endif
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#elif CONFIG_PIC && defined(_WIN32)
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.if \offset < 0
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adrp \rd, \val
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add \rd, \rd, :lo12:\val
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sub \rd, \rd, -(\offset)
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.else
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adrp \rd, \val+(\offset)
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add \rd, \rd, :lo12:\val+(\offset)
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.endif
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#elif CONFIG_PIC
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# if __has_feature(hwaddress_sanitizer)
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adrp \rd, :pg_hi21_nc:\val+(\offset)
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# else
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adrp \rd, \val+(\offset)
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# endif
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add \rd, \rd, :lo12:\val+(\offset)
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#else
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ldr \rd, =\val+\offset
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#endif
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.endm
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#define GLUE(a, b) a ## b
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#define JOIN(a, b) GLUE(a, b)
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#define X(s) JOIN(EXTERN_ASM, s)
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#define x18 do_not_use_x18
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#define w18 do_not_use_w18
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