1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * purgatory: Runs between two kernels 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * Copyright (C) 2014 Red Hat Inc. 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * Author: 8*4882a593Smuzhiyun * Vivek Goyal <vgoyal@redhat.com> 9*4882a593Smuzhiyun */ 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun #include <linux/bug.h> 12*4882a593Smuzhiyun #include <crypto/sha.h> 13*4882a593Smuzhiyun #include <asm/purgatory.h> 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun #include "../boot/string.h" 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory"); 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(".kexec-purgatory"); 20*4882a593Smuzhiyun verify_sha256_digest(void)21*4882a593Smuzhiyunstatic int verify_sha256_digest(void) 22*4882a593Smuzhiyun { 23*4882a593Smuzhiyun struct kexec_sha_region *ptr, *end; 24*4882a593Smuzhiyun u8 digest[SHA256_DIGEST_SIZE]; 25*4882a593Smuzhiyun struct sha256_state sctx; 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun sha256_init(&sctx); 28*4882a593Smuzhiyun end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun for (ptr = purgatory_sha_regions; ptr < end; ptr++) 31*4882a593Smuzhiyun sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun sha256_final(&sctx, digest); 34*4882a593Smuzhiyun 35*4882a593Smuzhiyun if (memcmp(digest, purgatory_sha256_digest, sizeof(digest))) 36*4882a593Smuzhiyun return 1; 37*4882a593Smuzhiyun 38*4882a593Smuzhiyun return 0; 39*4882a593Smuzhiyun } 40*4882a593Smuzhiyun purgatory(void)41*4882a593Smuzhiyunvoid purgatory(void) 42*4882a593Smuzhiyun { 43*4882a593Smuzhiyun int ret; 44*4882a593Smuzhiyun 45*4882a593Smuzhiyun ret = verify_sha256_digest(); 46*4882a593Smuzhiyun if (ret) { 47*4882a593Smuzhiyun /* loop forever */ 48*4882a593Smuzhiyun for (;;) 49*4882a593Smuzhiyun ; 50*4882a593Smuzhiyun } 51*4882a593Smuzhiyun } 52*4882a593Smuzhiyun 53*4882a593Smuzhiyun /* 54*4882a593Smuzhiyun * Defined in order to reuse memcpy() and memset() from 55*4882a593Smuzhiyun * arch/x86/boot/compressed/string.c 56*4882a593Smuzhiyun */ warn(const char * msg)57*4882a593Smuzhiyunvoid warn(const char *msg) {} 58