forked from Minki/linux
18b9c0d641
For historical reasons, the kernel Image must be loaded into physical memory at a 512 KB offset above a 2 MB aligned base address. The region between the base address and the start of the kernel Image has no significance to the kernel itself, but it is currently mapped explicitly into the early kernel VMA range for all translation granules. In some cases (i.e., 4 KB granule), this is unavoidable, due to the 2 MB granularity of the early kernel mappings. However, in other cases, e.g., when running with larger page sizes, or in the future, with more granular KASLR, there is no reason to map it explicitly like we do currently. So update the logic so that the region is mapped only if that happens as a side effect of rounding the start address of the kernel to swapper block size, and leave it unmapped otherwise. Since the symbol kernel_img_size now simply resolves to the memory footprint of the kernel Image, we can drop its definition from image.h and opencode its calculation. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
121 lines
4.3 KiB
C
121 lines
4.3 KiB
C
/*
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* Linker script macros to generate Image header fields.
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*
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* Copyright (C) 2014 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __ASM_IMAGE_H
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#define __ASM_IMAGE_H
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#ifndef LINKER_SCRIPT
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#error This file should only be included in vmlinux.lds.S
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#endif
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/*
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* There aren't any ELF relocations we can use to endian-swap values known only
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* at link time (e.g. the subtraction of two symbol addresses), so we must get
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* the linker to endian-swap certain values before emitting them.
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*
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* Note that, in order for this to work when building the ELF64 PIE executable
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* (for KASLR), these values should not be referenced via R_AARCH64_ABS64
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* relocations, since these are fixed up at runtime rather than at build time
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* when PIE is in effect. So we need to split them up in 32-bit high and low
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* words.
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*/
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#ifdef CONFIG_CPU_BIG_ENDIAN
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#define DATA_LE32(data) \
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((((data) & 0x000000ff) << 24) | \
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(((data) & 0x0000ff00) << 8) | \
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(((data) & 0x00ff0000) >> 8) | \
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(((data) & 0xff000000) >> 24))
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#else
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#define DATA_LE32(data) ((data) & 0xffffffff)
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#endif
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#define DEFINE_IMAGE_LE64(sym, data) \
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sym##_lo32 = DATA_LE32((data) & 0xffffffff); \
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sym##_hi32 = DATA_LE32((data) >> 32)
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#ifdef CONFIG_CPU_BIG_ENDIAN
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#define __HEAD_FLAG_BE 1
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#else
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#define __HEAD_FLAG_BE 0
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#endif
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#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
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#define __HEAD_FLAG_PHYS_BASE 1
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#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \
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(__HEAD_FLAG_PAGE_SIZE << 1) | \
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(__HEAD_FLAG_PHYS_BASE << 3))
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/*
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* These will output as part of the Image header, which should be little-endian
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* regardless of the endianness of the kernel. While constant values could be
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* endian swapped in head.S, all are done here for consistency.
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*/
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#define HEAD_SYMBOLS \
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DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \
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DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \
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DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
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#ifdef CONFIG_EFI
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__efistub_stext_offset = stext - _text;
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/*
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* Prevent the symbol aliases below from being emitted into the kallsyms
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* table, by forcing them to be absolute symbols (which are conveniently
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* ignored by scripts/kallsyms) rather than section relative symbols.
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* The distinction is only relevant for partial linking, and only for symbols
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* that are defined within a section declaration (which is not the case for
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* the definitions below) so the resulting values will be identical.
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*/
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#define KALLSYMS_HIDE(sym) ABSOLUTE(sym)
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/*
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* The EFI stub has its own symbol namespace prefixed by __efistub_, to
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* isolate it from the kernel proper. The following symbols are legally
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* accessed by the stub, so provide some aliases to make them accessible.
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* Only include data symbols here, or text symbols of functions that are
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* guaranteed to be safe when executed at another offset than they were
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* linked at. The routines below are all implemented in assembler in a
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* position independent manner
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*/
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__efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp);
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__efistub_memchr = KALLSYMS_HIDE(__pi_memchr);
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__efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy);
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__efistub_memmove = KALLSYMS_HIDE(__pi_memmove);
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__efistub_memset = KALLSYMS_HIDE(__pi_memset);
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__efistub_strlen = KALLSYMS_HIDE(__pi_strlen);
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__efistub_strnlen = KALLSYMS_HIDE(__pi_strnlen);
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__efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp);
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__efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp);
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__efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area);
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#ifdef CONFIG_KASAN
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__efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy);
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__efistub___memmove = KALLSYMS_HIDE(__pi_memmove);
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__efistub___memset = KALLSYMS_HIDE(__pi_memset);
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#endif
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__efistub__text = KALLSYMS_HIDE(_text);
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__efistub__end = KALLSYMS_HIDE(_end);
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__efistub__edata = KALLSYMS_HIDE(_edata);
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#endif
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#endif /* __ASM_IMAGE_H */
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