boot: Check shared area more carefully before init (dd6a84e3) · Commits · Wenxi XU / Mcuboot

When the shared data area is not exclusively used by MCUboot, but also by other boot stages it is inappropriate to initialize (erase) the shared area based on a global variable. It must check the magic value at the beginning of the area plus it should sanity-check other available values for a case when memory garbage matches the magic value. Change-Id: I3a4552ad2863a61d81de9374ef6302ae0609f7bf Signed-off-by:

David Vincze <david.vincze@arm.com>

boot/bootutil/src/boot_record.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -62,13 +62,18 @@ boot_add_data_to_shared_area(uint8_t major_type,

		boot_data = (struct shared_boot_data *)MCUBOOT_SHARED_DATA_BASE;

		/* Check whether first time to call this function. If does then initialise
		* shared data area.
		/* Check whether first time to call this function. If it is, then check
		* whether the shared data area needs to be initialised.
		*/
		if (!shared_memory_init_done) {
		memset((void *)MCUBOOT_SHARED_DATA_BASE, 0, MCUBOOT_SHARED_DATA_SIZE);
		if ((boot_data->header.tlv_magic != SHARED_DATA_TLV_INFO_MAGIC) \|\|
		(boot_data->header.tlv_tot_len > MCUBOOT_SHARED_DATA_SIZE)) {
		memset((void *)MCUBOOT_SHARED_DATA_BASE, 0,
		MCUBOOT_SHARED_DATA_SIZE);
		boot_data->header.tlv_magic = SHARED_DATA_TLV_INFO_MAGIC;
		boot_data->header.tlv_tot_len = SHARED_DATA_HEADER_SIZE;
		}

		shared_memory_init_done = true;
		}

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