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fb46d057db
- Add support for zstd compressed kernel - Define __DISABLE_EXPORTS in Makefile - Remove __DISABLE_EXPORTS definition from kaslr.c - Bump the heap size for zstd. - Update the documentation. Integrates the ZSTD decompression code to the x86 pre-boot code. Zstandard requires slightly more memory during the kernel decompression on x86 (192 KB vs 64 KB), and the memory usage is independent of the window size. __DISABLE_EXPORTS is now defined in the Makefile, which covers both the existing use in kaslr.c, and the use needed by the zstd decompressor in misc.c. This patch has been boot tested with both a zstd and gzip compressed kernel on i386 and x86_64 using buildroot and QEMU. Additionally, this has been tested in production on x86_64 devices. We saw a 2 second boot time reduction by switching kernel compression from xz to zstd. Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200730190841.2071656-7-nickrterrell@gmail.com
65 lines
1.8 KiB
C
65 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_BOOT_H
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#define _ASM_X86_BOOT_H
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#include <asm/pgtable_types.h>
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#include <uapi/asm/boot.h>
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/* Physical address where kernel should be loaded. */
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#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
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+ (CONFIG_PHYSICAL_ALIGN - 1)) \
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& ~(CONFIG_PHYSICAL_ALIGN - 1))
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/* Minimum kernel alignment, as a power of two */
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#ifdef CONFIG_X86_64
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# define MIN_KERNEL_ALIGN_LG2 PMD_SHIFT
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#else
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# define MIN_KERNEL_ALIGN_LG2 (PAGE_SHIFT + THREAD_SIZE_ORDER)
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#endif
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#define MIN_KERNEL_ALIGN (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2)
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#if (CONFIG_PHYSICAL_ALIGN & (CONFIG_PHYSICAL_ALIGN-1)) || \
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(CONFIG_PHYSICAL_ALIGN < MIN_KERNEL_ALIGN)
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# error "Invalid value for CONFIG_PHYSICAL_ALIGN"
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#endif
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#if defined(CONFIG_KERNEL_BZIP2)
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# define BOOT_HEAP_SIZE 0x400000
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#elif defined(CONFIG_KERNEL_ZSTD)
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/*
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* Zstd needs to allocate the ZSTD_DCtx in order to decompress the kernel.
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* The ZSTD_DCtx is ~160KB, so set the heap size to 192KB because it is a
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* round number and to allow some slack.
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*/
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# define BOOT_HEAP_SIZE 0x30000
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#else
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# define BOOT_HEAP_SIZE 0x10000
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#endif
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#ifdef CONFIG_X86_64
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# define BOOT_STACK_SIZE 0x4000
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# define BOOT_INIT_PGT_SIZE (6*4096)
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# ifdef CONFIG_RANDOMIZE_BASE
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/*
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* Assuming all cross the 512GB boundary:
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* 1 page for level4
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* (2+2)*4 pages for kernel, param, cmd_line, and randomized kernel
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* 2 pages for first 2M (video RAM: CONFIG_X86_VERBOSE_BOOTUP).
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* Total is 19 pages.
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*/
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# ifdef CONFIG_X86_VERBOSE_BOOTUP
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# define BOOT_PGT_SIZE (19*4096)
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# else /* !CONFIG_X86_VERBOSE_BOOTUP */
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# define BOOT_PGT_SIZE (17*4096)
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# endif
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# else /* !CONFIG_RANDOMIZE_BASE */
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# define BOOT_PGT_SIZE BOOT_INIT_PGT_SIZE
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# endif
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#else /* !CONFIG_X86_64 */
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# define BOOT_STACK_SIZE 0x1000
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#endif
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#endif /* _ASM_X86_BOOT_H */
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