34 lines
		
	
	
		
			733 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			34 lines
		
	
	
		
			733 B
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * Purgatory code running between two kernels.
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|  *
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|  * Copyright IBM Corp. 2018
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|  *
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|  * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com>
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|  */
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| 
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| #include <linux/kexec.h>
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| #include <linux/string.h>
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| #include <crypto/sha2.h>
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| #include <asm/purgatory.h>
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| 
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| int verify_sha256_digest(void)
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| {
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| 	struct kexec_sha_region *ptr, *end;
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| 	u8 digest[SHA256_DIGEST_SIZE];
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| 	struct sha256_state sctx;
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| 
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| 	sha256_init(&sctx);
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| 	end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions);
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| 
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| 	for (ptr = purgatory_sha_regions; ptr < end; ptr++)
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| 		sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
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| 
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| 	sha256_final(&sctx, digest);
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| 
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| 	if (memcmp(digest, purgatory_sha256_digest, sizeof(digest)))
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| 		return 1;
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| 
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| 	return 0;
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| }
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