46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* purgatory: Runs between two kernels
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*
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* Copyright (C) 2022 Huawei Technologies Co, Ltd.
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*
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* Author: Li Zhengyu (lizhengyu3@huawei.com)
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*
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*/
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#include <linux/purgatory.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <asm/string.h>
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u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory");
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struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(".kexec-purgatory");
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static int verify_sha256_digest(void)
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{
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struct kexec_sha_region *ptr, *end;
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struct sha256_state ss;
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u8 digest[SHA256_DIGEST_SIZE];
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sha256_init(&ss);
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end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions);
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for (ptr = purgatory_sha_regions; ptr < end; ptr++)
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sha256_update(&ss, (uint8_t *)(ptr->start), ptr->len);
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sha256_final(&ss, digest);
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if (memcmp(digest, purgatory_sha256_digest, sizeof(digest)) != 0)
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return 1;
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return 0;
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}
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/* workaround for a warning with -Wmissing-prototypes */
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void purgatory(void);
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void purgatory(void)
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{
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if (verify_sha256_digest())
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for (;;)
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/* loop forever */
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;
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}
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