1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * purgatory: Runs between two kernels 4 * 5 * Copyright (C) 2014 Red Hat Inc. 6 * 7 * Author: 8 * Vivek Goyal <vgoyal@redhat.com> 9 */ 10 11 #include <linux/bug.h> 12 #include <crypto/sha2.h> 13 #include <asm/purgatory.h> 14 15 #include "../boot/string.h" 16 17 u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory"); 18 19 struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(".kexec-purgatory"); 20 21 static int verify_sha256_digest(void) 22 { 23 struct kexec_sha_region *ptr, *end; 24 u8 digest[SHA256_DIGEST_SIZE]; 25 struct sha256_state sctx; 26 27 sha256_init(&sctx); 28 end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); 29 30 for (ptr = purgatory_sha_regions; ptr < end; ptr++) 31 sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); 32 33 sha256_final(&sctx, digest); 34 35 if (memcmp(digest, purgatory_sha256_digest, sizeof(digest))) 36 return 1; 37 38 return 0; 39 } 40 41 void purgatory(void) 42 { 43 int ret; 44 45 ret = verify_sha256_digest(); 46 if (ret) { 47 /* loop forever */ 48 for (;;) 49 ; 50 } 51 } 52 53 /* 54 * Defined in order to reuse memcpy() and memset() from 55 * arch/x86/boot/compressed/string.c 56 */ 57 void warn(const char *msg) {} 58