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-rw-r--r--arch/riscv/purgatory/purgatory.c45
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 */
+ ;
+}