388708028e
The arm64 assembler in binutils 2.32 and above generates a program
property note in a note section, .note.gnu.property, to encode used x86
ISAs and features. But the kernel linker script only contains a single
NOTE segment:
PHDRS
{
text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
note PT_NOTE FLAGS(4); /* PF_R */
}
The NOTE segment generated by the vDSO linker script is aligned to 4 bytes.
But the .note.gnu.property section must be aligned to 8 bytes on arm64.
$ readelf -n vdso64.so
Displaying notes found in: .note
Owner Data size Description
Linux 0x00000004 Unknown note type: (0x00000000)
description data: 06 00 00 00
readelf: Warning: note with invalid namesz and/or descsz found at offset 0x20
readelf: Warning: type: 0x78, namesize: 0x00000100, descsize: 0x756e694c, alignment: 8
Since the note.gnu.property section in the vDSO is not checked by the
dynamic linker, discard the .note.gnu.property sections in the vDSO.
Similar to commit 4caffe6a28 ("x86/vdso: Discard .note.gnu.property
sections in vDSO"), but for arm64.
Signed-off-by: Bill Wendling <morbo@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210423205159.830854-1-morbo@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
94 lines
2.0 KiB
ArmAsm
94 lines
2.0 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* GNU linker script for the VDSO library.
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*
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* Copyright (C) 2012 ARM Limited
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*
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* Author: Will Deacon <will.deacon@arm.com>
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* Heavily based on the vDSO linker scripts for other archs.
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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("elf64-littleaarch64", "elf64-bigaarch64", "elf64-littleaarch64")
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OUTPUT_ARCH(aarch64)
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SECTIONS
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{
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PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
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#ifdef CONFIG_TIME_NS
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PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
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#endif
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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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/*
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* Discard .note.gnu.property sections which are unused and have
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* different alignment requirement from vDSO note sections.
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*/
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/DISCARD/ : {
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*(.note.GNU-stack .note.gnu.property)
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}
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.note : { *(.note.*) } :text :note
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. = ALIGN(16);
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.text : { *(.text*) } :text =0xd503201f
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PROVIDE (__etext = .);
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PROVIDE (_etext = .);
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PROVIDE (etext = .);
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.dynamic : { *(.dynamic) } :text :dynamic
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.rodata : { *(.rodata*) } :text
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_end = .;
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PROVIDE(end = .);
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/DISCARD/ : {
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*(.data .data.* .gnu.linkonce.d.* .sdata*)
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*(.bss .sbss .dynbss .dynsbss)
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*(.eh_frame .eh_frame_hdr)
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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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/*
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* This controls what symbols we export from the DSO.
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*/
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VERSION
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{
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LINUX_2.6.39 {
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global:
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__kernel_rt_sigreturn;
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__kernel_gettimeofday;
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__kernel_clock_gettime;
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__kernel_clock_getres;
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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_sigtramp = __kernel_rt_sigreturn;
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