linux-zen-desktop/arch/riscv/purgatory/purgatory.c

46 lines
1.1 KiB
C

// 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_state ss;
u8 digest[SHA256_DIGEST_SIZE];
sha256_init(&ss);
end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions);
for (ptr = purgatory_sha_regions; ptr < end; ptr++)
sha256_update(&ss, (uint8_t *)(ptr->start), ptr->len);
sha256_final(&ss, 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 */
;
}