FM / purgatory

/usr/src/kernels/4.18.0-553.121.1.el8_10.x86_64/arch/x86/purgatory/

/usr/src/kernels/4.18.0-553.121.1.el8_10.x86_64/arch/x86/purgatory

Name	Size	Mode	Actions
entry64.S	1905	0644	edit dl rm
Makefile	1935	0644	edit dl rm
purgatory.c	1251	0644	edit dl rm
setup-x86_64.S	1113	0644	edit dl rm
stack.S	375	0644	edit dl rm

Edit: /usr/src/kernels/4.18.0-553.121.1.el8_10.x86_64/arch/x86/purgatory/purgatory.c (1251B)

/*
 * purgatory: Runs between two kernels
 *
 * Copyright (C) 2014 Red Hat Inc.
 *
 * Author:
 *       Vivek Goyal <vgoyal@redhat.com>
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */

#include <linux/bug.h>
#include <crypto/sha.h>
#include <asm/purgatory.h>

#include "../boot/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;
	u8 digest[SHA256_DIGEST_SIZE];
	struct sha256_state sctx;

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)))
		return 1;

return 0;
}

void purgatory(void)
{
	int ret;

ret = verify_sha256_digest();
	if (ret) {
		/* loop forever */
		for (;;)
			;
	}
}

/*
 * Defined in order to reuse memcpy() and memset() from
 * arch/x86/boot/compressed/string.c
 */
void warn(const char *msg) {}

/* * purgatory: Runs between two kernels * * Copyright (C) 2014 Red Hat Inc. * * Author: * Vivek Goyal * * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ #include #include #include #include "../boot/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; u8 digest[SHA256_DIGEST_SIZE]; struct sha256_state sctx; 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))) return 1; return 0; } void purgatory(void) { int ret; ret = verify_sha256_digest(); if (ret) { /* loop forever */ for (;;) ; } } /* * Defined in order to reuse memcpy() and memset() from * arch/x86/boot/compressed/string.c */ void warn(const char *msg) {}