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Ard BiesheuvelandGreg Kroah-Hartman
c59843e877
commit d55d5bc5d9 upstream.
The x86 decompressor is built and linked as a separate executable, but
it shares components with the kernel proper, which are either #include'd
as C files, or linked into the decompresor as a static library (e.g, the
EFI stub)
Both the kernel itself and the decompressor define a global symbol
'boot_params' to refer to the boot_params struct, but in the former
case, it refers to the struct directly, whereas in the decompressor, it
refers to a global pointer variable referring to the struct boot_params
passed by the bootloader or constructed from scratch.
This ambiguity is unfortunate, and makes it impossible to assign this
decompressor variable from the x86 EFI stub, given that declaring it as
extern results in a clash. So rename the decompressor version (whose
scope is limited) to boot_params_ptr.
[ mingo: Renamed 'boot_params_p' to 'boot_params_ptr' for clarity ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
[ardb: include references to boot_params in x86-stub.[ch]]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
94 lines
2.6 KiB
C
94 lines
2.6 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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/*
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* Used by decompressor's startup_32() to allocate page tables for identity
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* mapping of the 4G of RAM in 4-level paging mode:
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* - 1 level4 table;
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* - 1 level3 table;
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* - 4 level2 table that maps everything with 2M pages;
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*
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* The additional level5 table needed for 5-level paging is allocated from
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* trampoline_32bit memory.
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*/
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# define BOOT_INIT_PGT_SIZE (6*4096)
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/*
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* Total number of page tables kernel_add_identity_map() can allocate,
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* including page tables consumed by startup_32().
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*
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* Worst-case scenario:
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* - 5-level paging needs 1 level5 table;
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* - KASLR needs to map kernel, boot_params, cmdline and randomized kernel,
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* assuming all of them cross 256T boundary:
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* + 4*2 level4 table;
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* + 4*2 level3 table;
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* + 4*2 level2 table;
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* - X86_VERBOSE_BOOTUP needs to map the first 2M (video RAM):
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* + 1 level4 table;
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* + 1 level3 table;
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* + 1 level2 table;
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* Total: 28 tables
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*
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* Add 4 spare table in case decompressor touches anything beyond what is
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* accounted above. Warn if it happens.
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*/
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# define BOOT_PGT_SIZE_WARN (28*4096)
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# define BOOT_PGT_SIZE (32*4096)
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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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#ifndef __ASSEMBLY__
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extern unsigned int output_len;
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extern const unsigned long kernel_text_size;
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extern const unsigned long kernel_total_size;
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unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
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void (*error)(char *x));
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extern struct boot_params *boot_params_ptr;
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#endif
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#endif /* _ASM_X86_BOOT_H */
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