a7f71a2c89
Provide the arm64 compat (AArch32) vDSO in kernel/vdso32 in a similar way to what happens in kernel/vdso. The compat vDSO leverages on an adaptation of the arm architecture code with few changes: - Use of lib/vdso for gettimeofday - Implement a syscall based fallback - Introduce clock_getres() for the compat library - Implement trampolines - Implement elf note To build the compat vDSO a 32 bit compiler is required and needs to be specified via CONFIG_CROSS_COMPILE_COMPAT_VDSO. The code is not yet enabled as other prerequisites are missing. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-11-vincenzo.frascino@arm.com
83 lines
1.8 KiB
ArmAsm
83 lines
1.8 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Adapted from arm64 version.
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*
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* GNU linker script for the VDSO library.
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* Heavily based on the vDSO linker scripts for other archs.
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*
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* Copyright (C) 2012-2018 ARM Limited
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*/
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#include <linux/const.h>
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#include <asm/page.h>
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#include <asm/vdso.h>
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OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
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OUTPUT_ARCH(arm)
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SECTIONS
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{
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PROVIDE_HIDDEN(_vdso_data = . - PAGE_SIZE);
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. = VDSO_LBASE + SIZEOF_HEADERS;
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.hash : { *(.hash) } :text
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.gnu.hash : { *(.gnu.hash) }
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.dynsym : { *(.dynsym) }
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.dynstr : { *(.dynstr) }
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.gnu.version : { *(.gnu.version) }
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.gnu.version_d : { *(.gnu.version_d) }
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.gnu.version_r : { *(.gnu.version_r) }
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.note : { *(.note.*) } :text :note
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.dynamic : { *(.dynamic) } :text :dynamic
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.rodata : { *(.rodata*) } :text
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.text : { *(.text*) } :text =0xe7f001f2
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.got : { *(.got) }
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.rel.plt : { *(.rel.plt) }
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/DISCARD/ : {
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*(.note.GNU-stack)
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*(.data .data.* .gnu.linkonce.d.* .sdata*)
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*(.bss .sbss .dynbss .dynsbss)
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}
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}
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/*
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* We must supply the ELF program headers explicitly to get just one
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* PT_LOAD segment, and set the flags explicitly to make segments read-only.
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*/
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PHDRS
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{
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text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
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dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
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note PT_NOTE FLAGS(4); /* PF_R */
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}
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VERSION
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{
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LINUX_2.6 {
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global:
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__vdso_clock_gettime;
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__vdso_gettimeofday;
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__vdso_clock_getres;
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__kernel_sigreturn_arm;
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__kernel_sigreturn_thumb;
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__kernel_rt_sigreturn_arm;
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__kernel_rt_sigreturn_thumb;
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__vdso_clock_gettime64;
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local: *;
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};
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}
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/*
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* Make the sigreturn code visible to the kernel.
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*/
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VDSO_compat_sigreturn_arm = __kernel_sigreturn_arm;
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VDSO_compat_sigreturn_thumb = __kernel_sigreturn_thumb;
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VDSO_compat_rt_sigreturn_arm = __kernel_rt_sigreturn_arm;
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VDSO_compat_rt_sigreturn_thumb = __kernel_rt_sigreturn_thumb;
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