On Fri, 3 Dec 2021 at 19:21, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Sun, Nov 21, 2021 at 4:17 PM Chen Yu <yu.c.chen@xxxxxxxxx> wrote:
> >
> > Platform Firmware Runtime Update image starts with UEFI headers, and the
> > headers are defined in UEFI specification, but some of them have not been
> > defined in the kernel yet.
> >
> > For example, the header layout of a capsule file looks like this:
> >
> > EFI_CAPSULE_HEADER
> > EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
> > EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER
> > EFI_FIRMWARE_IMAGE_AUTHENTICATION
> >
> > These structures would be used by the Platform Firmware Runtime Update
> > driver to parse the format of capsule file to verify if the corresponding
> > version number is valid. In this way, if the user provides an invalid
> > capsule image, the kernel could be used as a guard to reject it, without
> > switching to the Management Mode (which might be costly).
> >
> > EFI_CAPSULE_HEADER has been defined in the kernel, but the other
> > structures have not been defined yet, so do that. Besides,
> > EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and
> > EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER are required to be packed
> > in the uefi specification. For this reason, use the __packed attribute
> > to indicate to the compiler that the entire structure can appear
> > misaligned in memory (as suggested by Ard) in case one of them follows
> > the other directly in a capsule header.
> >
> > Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> > ---
> > v11:Add explanation on why version check is introduced
> > in kernel rather than letting Management Mode to do it.
> > (Rafael J. Wysocki)
> > Revise the commit log to better describe the pack attribute.
> > (Rafael J. Wysocki)
> > Refine the comment for hw_ins and capsule_support.
> > (Rafael J. Wysocki)
> > v10:Remove the explicit assignment of the last item of enum.
> > (Andy Shevchenko)
> > v9: Use GUID_INIT() instead of guid_parse() during boot up.
> > (Andy Shevchenko)
> > Drop uuid, code_uuid, drv_uuid in struct pfru_device as they
> > are not needed. (Andy Shevchenko)
> > Drop type casting from void * in valid_version().
> > (Andy Shevchenko)
> > Use kfree() instead of ACPI_FREE() in non-ACPICA usage.
> > (Andy Shevchenko)
> > Use sizeof(rev) instead of sizeof(u32) in copy_from_user().
> > (Andy Shevchenko)
> > Generate physical address from MSB part to LSB.
> > (Andy Shevchenko)
> > Use devm_add_action_or_reset() to add ida release into dev resource
> > management. (Andy Shevchenko)
> > Use devm_kasprintf() instead of kasprintf() to format the
> > pfru_dev name.(Andy Shevchenko)
> > Remove redundant 0 in acpi_pfru_ids. (Andy Shevchenko)
> > Adjust the order of included headers in pfru.h.
> > (Andy Shevchenko)
> > Replace PFRU_MAGIC with PFRU_MAGIC_FOR_IOCTL in uapi file.
> > (Andy Shevchenko)
> > v8: Remove the variable-length array in struct pfru_update_cap_info, and
> > copy the non-variable-length struct pfru_update_cap_info to userspace
> > directly. (Greg Kroah-Hartman)
> > Change the type of rev_id from int to u32, because this data will
> > be copied between kernel and userspace. (Greg Kroah-Hartman)
> > Add a prefix for dev in struct pfru_device to parent_dev, so as
> > to indicate that this filed is the parent of the created miscdev.
> > (Greg Kroah-Hartman)
> > Use blank lines between different macro sections. (Greg Kroah-Hartman)
> > Illusatrate the possible errno for each ioctl interface.
> > (Greg Kroah-Hartman)
> > Remove pfru_valid_revid() from uapi header to avoid poluting the global
> > namespace.(Greg Kroah-Hartman)
> > Assign the value to the enum type explicitly.(Greg Kroah-Hartman)
> > Change the guid_t to efi_guid_t when parsing image header in get_image_type()
> > (Greg Kroah-Hartman)
> > Remove the void * to other type casting in valid_version(). (Andy Shevchenko)
> > Combined the assignment of variables with definitions. (Andy Shevchenko)
> > Define this magic for revision ID. (Andy Shevchenko)
> > Make the labeling consistent for error handling. (Andy Shevchenko)
> > Replace the UUID_SIZE in uapi with 16 directly. (Andy Shevchenko)
> > Add blank line between generic include header and uapi header.
> > (Andy Shevchenko)
> > Arrange the order between devm_kzalloc() and normal allocation in
> > acpi_pfru_probe() that, the former should always be ahead of the
> > latter. (Andy Shevchenko)
> > Move the UUID from uapi header to the c file. (Andy Shevchenko)
> > v7: Use ida_alloc() to allocate a ID, and release the ID when
> > device is removed. (Greg Kroah-Hartman)
> > Check the _DSM method at early stage, before allocate or parse
> > anything in acpi_pfru_probe(). (Greg Kroah-Hartman)
> > Set the parent of the misc device. (Greg Kroah-Hartman)
> > Use module_platform_driver() instead of platform_driver_register()
> > in module_init(). Separate pfru driver and pfru_telemetry driver
> > to two files. (Greg Kroah-Hartman)
> > v6: Use Link: tag to add the specification download address.
> > (Andy Shevchenko)
> > Remove linux/uuid.h and use raw buffers to contain uuid.
> > (Andy Shevchenko)
> > Drop comma for each terminator entry in the enum structure.
> > (Andy Shevchenko)
> > Remove redundant 'else' in get_image_type().
> > (Andy Shevchenko)
> > Directly return results from the switch cases in adjust_efi_size()
> > and pfru_ioctl().(Andy Shevchenko)
> > Keep comment style consistent by removing the period for
> > one line comment.
> > (Andy Shevchenko)
> > Remove devm_kfree() if .probe() failed.
> > (Andy Shevchenko)
> > v5: Remove Documentation/ABI/pfru, and move the content to kernel doc
> > in include/uapi/linux/pfru.h (Greg Kroah-Hartman)
> > Shrink the range of ioctl numbers declared in
> > Documentation/userspace-api/ioctl/ioctl-number.rst
> > from 16 to 8. (Greg Kroah-Hartman)
> > Change global variable struct pfru_device *pfru_dev to
> > per ACPI device. (Greg Kroah-Hartman)
> > Unregister the misc device in acpi_pfru_remove().
> > (Greg Kroah-Hartman)
> > Convert the kzalloc() to devm_kzalloc() in the driver so
> > as to avoid freeing the memory. (Greg Kroah-Hartman)
> > Fix the compile error by declaring the pfru_log_ioctl() as
> > static. (kernel test robot LKP)
> > Change to global variable misc_device to per ACPI device.
> > (Greg Kroah-Hartman)
> > v4: Replace all pr_err() with dev_dbg() (Greg Kroah-Hartman,
> > Rafael J. Wysocki)
> > Returns ENOTTY rather than ENOIOCTLCMD if invalid ioctl command
> > is provided. (Greg Kroah-Hartman)
> > Remove compat ioctl. (Greg Kroah-Hartman)
> > Rename /dev/pfru/pfru_update to /dev/acpi_pfru (Greg Kroah-Hartman)
> > Simplify the check for element of the package in query_capability()
> > (Rafael J. Wysocki)
> > Remove the loop in query_capability(), query_buffer() and query
> > the package elemenet directly. (Rafael J. Wysocki)
> > Check the the number of elements in case the number of package
> > elements is too small. (Rafael J. Wysocki)
> > Doing the assignment as initialization in get_image_type().
> > Meanwhile, returns the type or a negative error code in
> > get_image_type(). (Rafael J. Wysocki)
> > Put the comments inside the function. (Rafael J. Wysocki)
> > Returns the size or a negative error code in adjust_efi_size()
> > (Rafael J. Wysocki)
> > Fix the return value from EFAULT to EINVAL if pfru_valid_revid()
> > does not pass. (Rafael J. Wysocki)
> > Change the write() to be the code injection/update, the read() to
> > be telemetry retrieval and all of the rest to be ioctl()s under
> > one special device file.(Rafael J. Wysocki)
> > Putting empty code lines after an if () statement that is not
> > followed by a block. (Rafael J. Wysocki)
> > Remove "goto" tags to make the code more readable. (Rafael J. Wysocki)
> > v3: Use __u32 instead of int and __64 instead of unsigned long
> > in include/uapi/linux/pfru.h (Greg Kroah-Hartman)
> > Rename the structure in uapi to start with a prefix pfru so as
> > to avoid confusing in the global namespace. (Greg Kroah-Hartman)
> > v2: Add sanity check for duplicated instance of ACPI device.
> > Update the driver to work with allocated pfru_device objects.
> > (Mike Rapoport)
> > For each switch case pair, get rid of the magic case numbers
> > and add a default clause with the error handling.
> > (Mike Rapoport)
> > Move the obj->type checks outside the switch to reduce redundancy.
> > (Mike Rapoport)
> > Parse the code_inj_id and drv_update_id at driver initialization time
> > to reduce the re-parsing at runtime.(Mike Rapoport)
> > Explain in detail how the size needs to be adjusted when doing
> > version check.(Mike Rapoport)
> > Rename parse_update_result() to dump_update_result()(Mike Rapoport)
> > Remove redundant return.(Mike Rapoport)
> > Do not expose struct capsulate_buf_info to uapi, since it is
> > not needed in userspace.(Mike Rapoport)
> > ---
>
> OK, this is simple enough.
>
> Ard, any concerns?
>
Looks fine to me
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> > include/linux/efi.h | 46 +++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 46 insertions(+)
> >
> > diff --git a/include/linux/efi.h b/include/linux/efi.h
> > index dbd39b20e034..80e970f7e6f8 100644
> > --- a/include/linux/efi.h
> > +++ b/include/linux/efi.h
> > @@ -148,6 +148,52 @@ typedef struct {
> > u32 imagesize;
> > } efi_capsule_header_t;
> >
> > +/* EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER */
> > +struct efi_manage_capsule_header {
> > + u32 ver;
> > + u16 emb_drv_cnt;
> > + u16 payload_cnt;
> > + /*
> > + * Variable-size array of the size given by the sum of
> > + * emb_drv_cnt and payload_cnt.
> > + */
> > + u64 offset_list[];
> > +} __packed;
> > +
> > +/* EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER */
> > +struct efi_manage_capsule_image_header {
> > + u32 ver;
> > + efi_guid_t image_type_id;
> > + u8 image_index;
> > + u8 reserved_bytes[3];
> > + u32 image_size;
> > + u32 vendor_code_size;
> > + /* hw_ins was introduced in version 2 */
> > + u64 hw_ins;
> > + /* capsule_support was introduced in version 3 */
> > + u64 capsule_support;
> > +} __packed;
> > +
> > +/* WIN_CERTIFICATE */
> > +struct win_cert {
> > + u32 len;
> > + u16 rev;
> > + u16 cert_type;
> > +};
> > +
> > +/* WIN_CERTIFICATE_UEFI_GUID */
> > +struct win_cert_uefi_guid {
> > + struct win_cert hdr;
> > + efi_guid_t cert_type;
> > + u8 cert_data[];
> > +};
> > +
> > +/* EFI_FIRMWARE_IMAGE_AUTHENTICATION */
> > +struct efi_image_auth {
> > + u64 mon_count;
> > + struct win_cert_uefi_guid auth_info;
> > +};
> > +
> > /*
> > * EFI capsule flags
> > */
> > --
> > 2.25.1
> >
