Commit 2702809a authored Nov 05, 2019 by Nayna Jain Committed by Michael Ellerman Nov 12, 2019

powerpc: Detect the trusted boot state of the system



While secure boot permits only properly verified signed kernels to be
booted, trusted boot calculates the file hash of the kernel image and
stores the measurement prior to boot, that can be subsequently
compared against good known values via attestation services.

This patch reads the trusted boot state of a PowerNV system. The state
is used to conditionally enable additional measurement rules in the
IMA arch-specific policies.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e9eeee6b-b9bf-1e41-2954-61dbd6fbfbcf@linux.ibm.com

parent 4238fad3

arch/powerpc/include/asm/secure_boot.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,7 @@
		#ifdef CONFIG_PPC_SECURE_BOOT

		bool is_ppc_secureboot_enabled(void);
		bool is_ppc_trustedboot_enabled(void);

		#else

		@@ -19,5 +20,10 @@ static inline bool is_ppc_secureboot_enabled(void)
		return false;
		}

		static inline bool is_ppc_trustedboot_enabled(void)
		{
		return false;
		}

		#endif
		#endif

arch/powerpc/kernel/secure_boot.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -33,3 +33,18 @@ bool is_ppc_secureboot_enabled(void)

		return enabled;
		}

		bool is_ppc_trustedboot_enabled(void)
		{
		struct device_node *node;
		bool enabled = false;

		node = get_ppc_fw_sb_node();
		enabled = of_property_read_bool(node, "trusted-enabled");

		of_node_put(node);

		pr_info("Trusted boot mode %s\n", enabled ? "enabled" : "disabled");

		return enabled;
		}

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