// SPDX-License-Identifier: GPL-2.0-only /* * purgatory: Runs between two kernels * * Copyright (C) 2022 Huawei Technologies Co, Ltd. * * Author: Li Zhengyu (lizhengyu3@huawei.com) * */ #include <linux/purgatory.h> #include <linux/kernel.h> #include <linux/string.h> #include <asm/string.h> u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory"); struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(".kexec-purgatory"); static int verify_sha256_digest(void) { struct kexec_sha_region *ptr, *end; struct sha256_ctx sctx; u8 digest[SHA256_DIGEST_SIZE]; sha256_init(&sctx); end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); for (ptr = purgatory_sha_regions; ptr < end; ptr++) sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); sha256_final(&sctx, digest); if (memcmp(digest, purgatory_sha256_digest, sizeof(digest)) != 0) return 1; return 0; } /* workaround for a warning with -Wmissing-prototypes */ void purgatory(void); void purgatory(void) { if (verify_sha256_digest()) for (;;) /* loop forever */ ; }