Re: [PATCH v6 1/4] efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures

Greg Kroah-Hartman
2021-10-25T12:02:28Z

On Mon, Oct 25, 2021 at 07:45:19PM +0800, Chen Yu wrote:
> On Mon, Oct 25, 2021 at 08:44:00AM +0200, Greg Kroah-Hartman wrote:
> > On Mon, Oct 25, 2021 at 02:25:04PM +0800, Chen Yu 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. The EFI_CAPSULE_HEADER has been defined in the
> > > kernel, however the rest are not, thus introduce corresponding UEFI
> > > structures accordingly. Besides, EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
> > > and EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER need not be aligned and
> > > so the corresponding data types should be packed.
> > >
> > > Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> > > ---
> > > v6: No change since v5.
> > > v5: No change since v4.
> > > v4: Revise the commit log to make it more clear. (Rafael J. Wysocki)
> > > ---
> > > include/linux/efi.h | 50 +++++++++++++++++++++++++++++++++++++++++++++
> > > 1 file changed, 50 insertions(+)
> > >
> > > diff --git a/include/linux/efi.h b/include/linux/efi.h
> > > index 6b5d36babfcc..19ff834e1388 100644
> > > --- a/include/linux/efi.h
> > > +++ b/include/linux/efi.h
> > > @@ -148,6 +148,56 @@ typedef struct {
> > > u32 imagesize;
> > > } efi_capsule_header_t;
> > >
> > > +#pragma pack(1)
> >
> > Why is this pragma suddenly needed now in this file?
> >
> > If you really need this for a specific structure, use the "__packed"
> > attribute please.
> >
> These two structures are required to be packed in the uefi spec, I'll change
> them to "__packed".

And they are the _only_ ones in this .h file that require this? I would
think that they all require this.

thanks,

greg k-h