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6e64bc845f
osreldate.h and sys/param.h were manually adjusted to not __FreeBSD_version since it will be defined by the compiler.
221 lines
7.5 KiB
C
Vendored
221 lines
7.5 KiB
C
Vendored
/*-
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* Copyright (c) 2014 Andrew Turner
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifdef __arm__
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#include <arm/asm.h>
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#else /* !__arm__ */
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#ifndef _MACHINE_ASM_H_
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#define _MACHINE_ASM_H_
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#undef __FBSDID
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#if !defined(lint) && !defined(STRIP_FBSDID)
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#define __FBSDID(s) .ident s
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#else
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#define __FBSDID(s) /* nothing */
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#endif
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#define _C_LABEL(x) x
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#ifdef KDTRACE_HOOKS
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#define DTRACE_NOP nop
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#else
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#define DTRACE_NOP
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#endif
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#define LENTRY(sym) \
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.text; .align 2; .type sym,#function; sym: \
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.cfi_startproc; BTI_C; DTRACE_NOP
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#define ENTRY(sym) \
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.globl sym; LENTRY(sym)
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#define EENTRY(sym) \
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.globl sym; .text; .align 2; .type sym,#function; sym:
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#define LEND(sym) .ltorg; .cfi_endproc; .size sym, . - sym
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#define END(sym) LEND(sym)
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#define EEND(sym)
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#define WEAK_REFERENCE(sym, alias) \
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.weak alias; \
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.set alias,sym
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#define UINT64_C(x) (x)
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#if defined(PIC)
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#define PIC_SYM(x,y) x ## @ ## y
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#else
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#define PIC_SYM(x,y) x
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#endif
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/* Alias for link register x30 */
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#define lr x30
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/*
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* Sets the trap fault handler. The exception handler will return to the
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* address in the handler register on a data abort or the xzr register to
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* clear the handler. The tmp parameter should be a register able to hold
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* the temporary data.
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*/
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#define SET_FAULT_HANDLER(handler, tmp) \
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ldr tmp, [x18, #PC_CURTHREAD]; /* Load curthread */ \
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ldr tmp, [tmp, #TD_PCB]; /* Load the pcb */ \
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str handler, [tmp, #PCB_ONFAULT] /* Set the handler */
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#define ENTER_USER_ACCESS(reg, tmp) \
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ldr tmp, =has_pan; /* Get the addr of has_pan */ \
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ldr reg, [tmp]; /* Read it */ \
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cbz reg, 997f; /* If no PAN skip */ \
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.inst 0xd500409f | (0 << 8); /* Clear PAN */ \
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997:
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#define EXIT_USER_ACCESS(reg) \
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cbz reg, 998f; /* If no PAN skip */ \
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.inst 0xd500409f | (1 << 8); /* Set PAN */ \
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998:
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#define EXIT_USER_ACCESS_CHECK(reg, tmp) \
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ldr tmp, =has_pan; /* Get the addr of has_pan */ \
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ldr reg, [tmp]; /* Read it */ \
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cbz reg, 999f; /* If no PAN skip */ \
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.inst 0xd500409f | (1 << 8); /* Set PAN */ \
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999:
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/*
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* Some AArch64 CPUs speculate past an eret instruction. As the user may
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* control the registers at this point add a speculation barrier usable on
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* all AArch64 CPUs after the eret instruction.
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* TODO: ARMv8.5 adds a specific instruction for this, we could use that
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* if we know we are running on something that supports it.
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*/
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#define ERET \
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eret; \
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dsb sy; \
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isb
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/*
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* When a CPU that implements FEAT_BTI uses a BR/BLR instruction (or the
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* pointer authentication variants, e.g. BLRAA) and the target location
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* has the GP attribute in its page table, then the target of the BR/BLR
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* needs to be a valid BTI landing pad.
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*
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* BTI_C should be used at the start of a function and is used in the
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* ENTRY macro. It can be replaced by PACIASP or PACIBSP, however these
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* also need an appropriate authenticate instruction before returning.
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*
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* BTI_J should be used as the target instruction when branching with a
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* BR instruction within a function.
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*
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* When using a BR to branch to a new function, e.g. a tail call, then
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* the target register should be x16 or x17 so it is compatible with
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* the BRI_C instruction.
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*
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* As these instructions are in the hint space they are a NOP when
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* the CPU doesn't implement FEAT_BTI so are safe to use.
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*/
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#ifdef __ARM_FEATURE_BTI_DEFAULT
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#define BTI_C hint #34
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#define BTI_J hint #36
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#else
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#define BTI_C
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#define BTI_J
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#endif
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/*
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* To help protect against ROP attacks we can use Pointer Authentication
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* to sign the return address before pushing it to the stack.
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*
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* PAC_LR_SIGN can be used at the start of a function to sign the link
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* register with the stack pointer as the modifier. As this is in the hint
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* space it is safe to use on CPUs that don't implement pointer
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* authentication. It can be used in place of the BTI_C instruction above as
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* a valid BTI landing pad instruction.
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*
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* PAC_LR_AUTH is used to authenticate the link register using the stack
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* pointer as the modifier. It should be used in any function that uses
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* PAC_LR_SIGN. The stack pointer must be identical in each case.
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*/
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#ifdef __ARM_FEATURE_PAC_DEFAULT
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#define PAC_LR_SIGN hint #25 /* paciasp */
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#define PAC_LR_AUTH hint #29 /* autiasp */
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#else
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#define PAC_LR_SIGN
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#define PAC_LR_AUTH
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#endif
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/*
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* GNU_PROPERTY_AARCH64_FEATURE_1_NOTE can be used to insert a note that
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* the current assembly file is built with Pointer Authentication (PAC) or
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* Branch Target Identification support (BTI). As the linker requires all
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* object files in an executable or library to have the GNU property
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* note to emit it in the created elf file we need to add a note to all
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* assembly files that support BTI so the kernel and dynamic linker can
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* mark memory used by the file as guarded.
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*
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* The GNU_PROPERTY_AARCH64_FEATURE_1_VAL macro encodes the combination
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* of PAC and BTI that have been enabled. It can be used as follows:
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* GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL);
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*
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* To use this you need to include <sys/elf_common.h> for
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* GNU_PROPERTY_AARCH64_FEATURE_1_*
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*/
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#if defined(__ARM_FEATURE_BTI_DEFAULT)
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#if defined(__ARM_FEATURE_PAC_DEFAULT)
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/* BTI, PAC */
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#define GNU_PROPERTY_AARCH64_FEATURE_1_VAL \
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(GNU_PROPERTY_AARCH64_FEATURE_1_BTI | GNU_PROPERTY_AARCH64_FEATURE_1_PAC)
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#else
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/* BTI, no PAC */
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#define GNU_PROPERTY_AARCH64_FEATURE_1_VAL \
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(GNU_PROPERTY_AARCH64_FEATURE_1_BTI)
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#endif
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#elif defined(__ARM_FEATURE_PAC_DEFAULT)
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/* No BTI, PAC */
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#define GNU_PROPERTY_AARCH64_FEATURE_1_VAL \
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(GNU_PROPERTY_AARCH64_FEATURE_1_PAC)
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#else
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/* No BTI, no PAC */
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#define GNU_PROPERTY_AARCH64_FEATURE_1_VAL 0
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#endif
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#if defined(__ARM_FEATURE_BTI_DEFAULT) || defined(__ARM_FEATURE_PAC_DEFAULT)
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#define GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(x) \
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.section .note.gnu.property, "a"; \
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.balign 8; \
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.4byte 0x4; /* sizeof(vendor) */ \
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.4byte 0x10; /* sizeof(note data) */ \
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.4byte (NT_GNU_PROPERTY_TYPE_0); \
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.asciz "GNU"; /* vendor */ \
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/* note data: */ \
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.4byte (GNU_PROPERTY_AARCH64_FEATURE_1_AND); \
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.4byte 0x4; /* sizeof(property) */ \
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.4byte (x); /* property */ \
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.4byte 0
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#else
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#define GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(x)
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#endif
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#endif /* _MACHINE_ASM_H_ */
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#endif /* !__arm__ */ |