Merge "fs_mgr_verity: support updating actual block device path in verity table" (4c28ca1a) · Commits · e / os / android_system_core

fs_mgr/fs_mgr_verity.cpp

+41 −14

Original line number	Diff line number	Diff line
		@@ -689,27 +689,55 @@ int load_verity_state(struct fstab_rec* fstab, int* mode) {
		return read_verity_state(fstab->verity_loc, offset, mode);
		}

		static void update_verity_table_blk_device(char blk_device, char *table)
		{
		std::string result, word;
		// Update the verity table using the actual block device path.
		// Two cases:
		// Case-1: verity table is shared for devices with different by-name prefix.
		// Example:
		// verity table token: /dev/block/bootdevice/by-name/vendor
		// blk_device-1 (non-A/B): /dev/block/platform/soc.0/7824900.sdhci/by-name/vendor
		// blk_device-2 (A/B): /dev/block/platform/soc.0/f9824900.sdhci/by-name/vendor_a
		//
		// Case-2: append A/B suffix in the verity table.
		// Example:
		// verity table token: /dev/block/platform/soc.0/7824900.sdhci/by-name/vendor
		// blk_device: /dev/block/platform/soc.0/7824900.sdhci/by-name/vendor_a
		static void update_verity_table_blk_device(const std::string& blk_device, char** table,
		bool slot_select) {
		bool updated = false;
		std::string result, ab_suffix;
		auto tokens = android::base::Split(*table, " ");

		// If slot_select is set, it means blk_device is already updated with ab_suffix.
		if (slot_select) ab_suffix = fs_mgr_get_slot_suffix();

		for (const auto& token : tokens) {
		if (android::base::StartsWith(token, "/dev/block/") &&
		android::base::StartsWith(blk_device, token.c_str())) {
		word = blk_device;
		std::string new_token;
		if (android::base::StartsWith(token, "/dev/block/")) {
		if (token == blk_device) return; // no need to update if they're already the same.
		std::size_t found1 = blk_device.find("by-name");
		std::size_t found2 = token.find("by-name");
		if (found1 != std::string::npos && found2 != std::string::npos &&
		blk_device.substr(found1) == token.substr(found2) + ab_suffix) {
		new_token = blk_device;
		}
		}

		if (!new_token.empty()) {
		updated = true;
		LINFO << "Verity table: updated block device from '" << token << "' to '" << new_token
		<< "'";
		} else {
		word = token;
		new_token = token;
		}

		if (result.empty()) {
		result = word;
		result = new_token;
		} else {
		result += " " + word;
		result += " " + new_token;
		}
		}

		if (result.empty()) {
		if (!updated) {
		return;
		}

		@@ -825,10 +853,9 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab, bool wait_for_verity_dev)
		LINFO << "Enabling dm-verity for " << mount_point.c_str()
		<< " (mode " << params.mode << ")";

		if (fstab->fs_mgr_flags & MF_SLOTSELECT) {
		// Update the verity params using the actual block device path
		update_verity_table_blk_device(fstab->blk_device, &params.table);
		}
		update_verity_table_blk_device(fstab->blk_device, &params.table,
		fstab->fs_mgr_flags & MF_SLOTSELECT);

		// load the verity mapping table
		if (load_verity_table(io, mount_point, verity.data_size, fd, &params,