qemu

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/*
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 * aarch64 linux replacement vdso.
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 *
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 * Copyright 2023 Linaro, Ltd.
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 *
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 * SPDX-License-Identifier: GPL-2.0-or-later
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 */
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#include <asm/unistd.h>
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/* ??? These are in include/elf.h, which is not ready for inclusion in asm. */
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#define NT_GNU_PROPERTY_TYPE_0  5
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#define GNU_PROPERTY_AARCH64_FEATURE_1_AND      0xc0000000
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#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI      (1U << 0)
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#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC      (1U << 1)
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#define GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT \
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    (GNU_PROPERTY_AARCH64_FEATURE_1_BTI | GNU_PROPERTY_AARCH64_FEATURE_1_PAC)
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	.section .note.gnu.property
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	.align	3
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	.long	2f - 1f
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	.long	6f - 3f
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	.long	NT_GNU_PROPERTY_TYPE_0
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1:	.string	"GNU"
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2:	.align	3
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3:	.long	GNU_PROPERTY_AARCH64_FEATURE_1_AND
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	.long	5f - 4f
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4:	.long	GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT
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5:	.align	3
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6:
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	.text
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.macro endf name
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	.globl	\name
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	.type	\name, @function
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	.size	\name, . - \name
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.endm
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.macro vdso_syscall name, nr
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\name:
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	bti	c
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	mov	x8, #\nr
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	svc	#0
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	ret
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endf	\name
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.endm
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	.cfi_startproc
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vdso_syscall __kernel_gettimeofday, __NR_gettimeofday
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vdso_syscall __kernel_clock_gettime, __NR_clock_gettime
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vdso_syscall __kernel_clock_getres, __NR_clock_getres
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	.cfi_endproc
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/*
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 * TODO: The kernel makes a big deal of turning off the .cfi directives,
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 * because they cause libgcc to crash, but that's because they're wrong.
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 *
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 * For now, elide the unwind info for __kernel_rt_sigreturn and rely on
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 * the libgcc fallback routine as we have always done.  This requires
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 * that the code sequence used be exact.
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 *
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 * Add a nop as a spacer to ensure that unwind does not pick up the
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 * unwind info from the preceding syscall.
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 */
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	nop
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__kernel_rt_sigreturn:
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	/* No BTI C insn here -- we arrive via RET. */
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	mov	x8, #__NR_rt_sigreturn
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	svc	#0
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endf	__kernel_rt_sigreturn
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