On Fri, May 20, 2022 at 05:36:06PM -0700, Russ Weight wrote:
> 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.
>
> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
Acked-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> ---
> v21:
> - Replace WARN_ON(size % stride) with a more elaborate test. Return
> -EINVAL and write a message to the kernel log. Call WARN_ON_ONCE().
> v20:
> - Added text to the commit message to further describe the cancellation of
> code signing keys.
> v19:
> - Change "card bmc" naming back to "m10 bmc" naming to be consistent
> with the parent driver.
> v18:
> - No change
> v17:
> - Update the Date and KernelVersion for the ABI documentation to Jul 2022
> and 5.19 respectively.
> - Change "m10bmc" in symbol names to "cardbmc" to reflect the fact that the
> future devices will not necessarily use the MAX10.
> v16:
> - No Change
> v15:
> - Updated the Dates and KernelVersions in the ABI documentation
> v14:
> - No changes
> v13:
> - Updated ABI documentation date and kernel version
> v12:
> - Updated Date and KernelVersion fields in ABI documentation
> v11:
> - No change
> v10:
> - Changed the path expressions in the sysfs documentation to
> replace the n3000 reference with something more generic to
> accomodate other devices that use the same driver.
> v9:
> - Rebased to 5.12-rc2 next
> - Updated Date and KernelVersion in ABI documentation
> v8:
> - Previously patch 4/6, otherwise no change
> v7:
> - Updated Date and KernelVersion in ABI documentation
> v6:
> - Added WARN_ON() call for (size / stride) to ensure
> that the proper count is passed to regmap_bulk_read().
> v5:
> - No change
> v4:
> - Moved sysfs files for displaying the code-signing-key (CSK)
> cancellation vectors from the FPGA Security Manger class driver
> to here. The m10bmc_csk_vector() and m10bmc_csk_cancel_nbits()
> functions are removed and the functionality from these functions
> is moved into a show_canceled_csk() function for for displaying
> the CSK vectors.
> - Added ABI documentation for new sysfs entries
> v3:
> - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
> - Changed "MAX10 BMC Secure Engine driver" to "MAX10 BMC Secure Update
> driver"
> - Removed wrapper functions (m10bmc_raw_*, m10bmc_sys_*). The
> underlying functions are now called directly.
> - Renamed get_csk_vector() to m10bmc_csk_vector()
> v2:
> - Replaced small function-creation macros for explicit function
> declarations.
> - Fixed get_csk_vector() function to properly apply the stride
> variable in calls to m10bmc_raw_bulk_read()
> - Added m10bmc_ prefix to functions in m10bmc_iops structure
> ---
> .../sysfs-driver-intel-m10-bmc-sec-update | 24 +++++++++
> drivers/fpga/intel-m10-bmc-sec-update.c | 54 +++++++++++++++++++
> 2 files changed, 78 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update
> index 1132e39b2125..ca5a34c1c31f 100644
> --- a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update
> +++ b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update
> @@ -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: Jul 2022
> +KernelVersion: 5.19
> +Contact: Russ Weight <russell.h.weight@xxxxxxxxx>
> +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: Jul 2022
> +KernelVersion: 5.19
> +Contact: Russ Weight <russell.h.weight@xxxxxxxxx>
> +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: Jul 2022
> +KernelVersion: 5.19
> +Contact: Russ Weight <russell.h.weight@xxxxxxxxx>
> +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: Jul 2022
> KernelVersion: 5.19
> diff --git a/drivers/fpga/intel-m10-bmc-sec-update.c b/drivers/fpga/intel-m10-bmc-sec-update.c
> index 25b21f116976..65fec2a70901 100644
> --- a/drivers/fpga/intel-m10-bmc-sec-update.c
> +++ b/drivers/fpga/intel-m10-bmc-sec-update.c
> @@ -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,
> };
>
> --
> 2.25.1
