On Sun, Apr 29, 2018 at 09:43:18AM +0200, Ingo Molnar wrote:
> * Hans de Goede <[email protected]> wrote:
> > diff --git a/arch/x86/boot/compressed/eboot.c 
> > b/arch/x86/boot/compressed/eboot.c
> > index 47d3efff6805..8650ab268ee7 100644
> > --- a/arch/x86/boot/compressed/eboot.c
> > +++ b/arch/x86/boot/compressed/eboot.c
> > @@ -122,7 +122,14 @@ __setup_efi_pci32(efi_pci_io_protocol_32 *pci, struct 
> > pci_setup_rom **__rom)
> >     if (status != EFI_SUCCESS)
> >             return status;
> >  
> > -   if (!pci->romimage || !pci->romsize)
> > +   /*
> > +    * Some firmwares contain EFI function pointers at the place where the
> > +    * romimage and romsize fields are supposed to be. Typically the EFI
> > +    * code is mapped at high addresses, translating to an unrealistically
> > +    * large romsize. The UEFI spec limits the size of option ROMs to 16
> > +    * MiB so we reject any roms over 16 MiB in size to catch this.
> > +    */
> > +   if (!pci->romimage || !pci->romsize || pci->romsize > 0x1000000)
> >             return EFI_INVALID_PARAMETER;
> >  
> >     size = pci->romsize + sizeof(*rom);
> > @@ -230,7 +237,14 @@ __setup_efi_pci64(efi_pci_io_protocol_64 *pci, struct 
> > pci_setup_rom **__rom)
> >     if (status != EFI_SUCCESS)
> >             return status;
> >  
> > -   if (!pci->romimage || !pci->romsize)
> > +   /*
> > +    * Some firmwares contain EFI function pointers at the place where the
> > +    * romimage and romsize fields are supposed to be. Typically the EFI
> > +    * code is mapped at high addresses, translating to an unrealistically
> > +    * large romsize. The UEFI spec limits the size of option ROMs to 16
> > +    * MiB so we reject any roms over 16 MiB in size to catch this.
> > +    */
> > +   if (!pci->romimage || !pci->romsize || pci->romsize > 0x1000000)
> >             return EFI_INVALID_PARAMETER;
> 
> Any reason why this couldn't be factored out into a efi_check_rom(pci)
> kind of helper function, which would unify the logic and would also
> avoid the duplicate comment blocks?

The real fix would be to deduplicate __setup_efi_pci32 and __setup_efi_pci64
à la commits 2bd79f30eea1 and db4545d9a788.

(That said the comment seems overly wordy.  A short pointer to the UEFI spec
with chapter number should be sufficient, anything else should be in the
changelog.  Just my 2 cents anyway.)

Thanks,

Lukas
--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to