Unverified Commit 7f03d84a authored by Russ Weight's avatar Russ Weight Committed by Xu Yilun
Browse files

fpga: m10bmc-sec: expose max10 canceled keys in sysfs 



Extend the MAX10 BMC Secure Update driver to provide sysfs files to
expose the 128 bit code signing key (CSK) cancellation vectors. These use
the standard bitmap list format (e.g. 1,2-6,9).

Each CSK is assigned an ID, a number between 0-127, during the signing
process. CSK ID cancellation information is stored in 128-bit fields in
write-once locations in flash.  The cancellation of a CSK can be used
to prevent the card from being rolled back to older images that were
signed with a CSK that is now cancelled.

Reviewed-by: default avatarTom Rix <trix@redhat.com>
Tested-by: default avatarTianfei Zhang <tianfei.zhang@intel.com>
Signed-off-by: default avatarRuss Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220606160038.846236-5-russell.h.weight@intel.com


Signed-off-by: default avatarXu Yilun <yilun.xu@intel.com>
parent 154afa5c

Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update

+24 −0
Original line number Diff line number Diff line
@@ -28,6 +28,30 @@ Description: Read only. Returns the root entry hash for the BMC image 
		underlying device supports it.

		Format: string.



What:		/sys/bus/platform/drivers/intel-m10bmc-sec-update/.../security/sr_canceled_csks

Date:		Sep 2022

KernelVersion:	5.20

Contact:	Russ Weight <russell.h.weight@intel.com>

Description:	Read only. Returns a list of indices for canceled code

		signing keys for the static region. The standard bitmap

		list format is used (e.g. "1,2-6,9").



What:		/sys/bus/platform/drivers/intel-m10bmc-sec-update/.../security/pr_canceled_csks

Date:		Sep 2022

KernelVersion:	5.20

Contact:	Russ Weight <russell.h.weight@intel.com>

Description:	Read only. Returns a list of indices for canceled code

		signing keys for the partial reconfiguration region. The

		standard bitmap list format is used (e.g. "1,2-6,9").



What:		/sys/bus/platform/drivers/intel-m10bmc-sec-update/.../security/bmc_canceled_csks

Date:		Sep 2022

KernelVersion:	5.20

Contact:	Russ Weight <russell.h.weight@intel.com>

Description:	Read only. Returns a list of indices for canceled code

		signing keys for the BMC.  The standard bitmap list format

		is used (e.g. "1,2-6,9").



What:		/sys/bus/platform/drivers/intel-m10bmc-sec-update/.../security/flash_count

Date:		Sep 2022

KernelVersion:	5.20

drivers/fpga/intel-m10-bmc-sec-update.c

+54 −0
Original line number Diff line number Diff line
@@ -78,6 +78,57 @@ DEVICE_ATTR_SEC_REH_RO(bmc, BMC_PROG_MAGIC, BMC_PROG_ADDR, BMC_REH_ADDR); 
DEVICE_ATTR_SEC_REH_RO(sr, SR_PROG_MAGIC, SR_PROG_ADDR, SR_REH_ADDR);

DEVICE_ATTR_SEC_REH_RO(pr, PR_PROG_MAGIC, PR_PROG_ADDR, PR_REH_ADDR);



#define CSK_BIT_LEN		128U

#define CSK_32ARRAY_SIZE	DIV_ROUND_UP(CSK_BIT_LEN, 32)



static ssize_t

show_canceled_csk(struct device *dev, u32 addr, char *buf)

{

	unsigned int i, stride, size = CSK_32ARRAY_SIZE * sizeof(u32);

	struct m10bmc_sec *sec = dev_get_drvdata(dev);

	DECLARE_BITMAP(csk_map, CSK_BIT_LEN);

	__le32 csk_le32[CSK_32ARRAY_SIZE];

	u32 csk32[CSK_32ARRAY_SIZE];

	int ret;



	stride = regmap_get_reg_stride(sec->m10bmc->regmap);

	if (size % stride) {

		dev_err(sec->dev,

			"CSK vector size (0x%x) not aligned to stride (0x%x)\n",

			size, stride);

		WARN_ON_ONCE(1);

		return -EINVAL;

	}



	ret = regmap_bulk_read(sec->m10bmc->regmap, addr, csk_le32,

			       size / stride);

	if (ret) {

		dev_err(sec->dev, "failed to read CSK vector: %x cnt %x: %d\n",

			addr, size / stride, ret);

		return ret;

	}



	for (i = 0; i < CSK_32ARRAY_SIZE; i++)

		csk32[i] = le32_to_cpu(((csk_le32[i])));



	bitmap_from_arr32(csk_map, csk32, CSK_BIT_LEN);

	bitmap_complement(csk_map, csk_map, CSK_BIT_LEN);

	return bitmap_print_to_pagebuf(1, buf, csk_map, CSK_BIT_LEN);

}



#define DEVICE_ATTR_SEC_CSK_RO(_name, _addr) \

static ssize_t _name##_canceled_csks_show(struct device *dev, \

					  struct device_attribute *attr, \

					  char *buf) \

{ return show_canceled_csk(dev, _addr, buf); } \

static DEVICE_ATTR_RO(_name##_canceled_csks)



#define CSK_VEC_OFFSET 0x34



DEVICE_ATTR_SEC_CSK_RO(bmc, BMC_PROG_ADDR + CSK_VEC_OFFSET);

DEVICE_ATTR_SEC_CSK_RO(sr, SR_PROG_ADDR + CSK_VEC_OFFSET);

DEVICE_ATTR_SEC_CSK_RO(pr, PR_PROG_ADDR + CSK_VEC_OFFSET);



#define FLASH_COUNT_SIZE 4096	/* count stored as inverted bit vector */



static ssize_t flash_count_show(struct device *dev,
@@ -125,6 +176,9 @@ static struct attribute *m10bmc_security_attrs[] = { 
	&dev_attr_bmc_root_entry_hash.attr,

	&dev_attr_sr_root_entry_hash.attr,

	&dev_attr_pr_root_entry_hash.attr,

	&dev_attr_sr_canceled_csks.attr,

	&dev_attr_pr_canceled_csks.attr,

	&dev_attr_bmc_canceled_csks.attr,

	NULL,

};