diff options
Diffstat (limited to 'arch/riscv/purgatory/purgatory.c')
-rw-r--r-- | arch/riscv/purgatory/purgatory.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/riscv/purgatory/purgatory.c b/arch/riscv/purgatory/purgatory.c new file mode 100644 index 000000000..80596ab5f --- /dev/null +++ b/arch/riscv/purgatory/purgatory.c @@ -0,0 +1,45 @@ +// 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 */ + ; +} |