Re: [edk2-devel] [PATCH v3 0/4] ArmPkg/SecurityPkg: Fixes for ArmTrngLib/RngDxe

["Ard Biesheuvel" <ardb@kernel.org>]

On Tue, 7 Mar 2023 at 08:53, Yao, Jiewen <jiewen.yao@intel.com> wrote:
>
> I don’t mind, please go ahead.
>

Thanks. Merged as #4109

Note that I replaced the 'return EFI_UNSUPPORTED' with 'return
EFI_REQUEST_UNLOAD_IMAGE' so that RngDxe is simply unloaded again
without an error if no RNG sources are available to it.


> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard
> > Biesheuvel
> > Sent: Tuesday, March 7, 2023 12:22 AM
> > To: Yao, Jiewen <jiewen.yao@intel.com>
> > Cc: Pierre Gondois <pierre.gondois@arm.com>; devel@edk2.groups.io; Leif
> > Lindholm <leif@nuviainc.com>; Sami Mujawar <sami.mujawar@arm.com>;
> > Wang, Jian J <jian.j.wang@intel.com>
> > Subject: Re: [edk2-devel] [PATCH v3 0/4] ArmPkg/SecurityPkg: Fixes for
> > ArmTrngLib/RngDxe
> >
> > On Mon, 6 Mar 2023 at 16:42, Yao, Jiewen <jiewen.yao@intel.com> wrote:
> > >
> > > Hi Pierre
> > > I don’t have strong opinion.
> > >
> > > For ARM specific patch, would you please get R-B from ARM expert?
> > >
> > > I think we need to wait for the response from Ard to confirm.
> > >
> >
> > These patches
> >
> >   SecurityPkg/RngDxe: Correctly update mAvailableAlgoArrayCount
> >   SecurityPkg/RngDxe: Conditionally install EFI_RNG_PROTOCOL
> >
> > Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
> >
> > Jiewen, if you don't mind, I will merge those right away.
> >
> > For the remaining patch, I am not sure I understand why the behavior
> > regarding the zero GUID is correct. Perhaps we could
> > revisit/resend/review that patch in isolation?
> >
> > Thanks,
> > Ard.
> >
> >
> >
> >
> > >
> > > > -----Original Message-----
> > > > From: Pierre Gondois <pierre.gondois@arm.com>
> > > > Sent: Monday, March 6, 2023 11:38 PM
> > > > To: devel@edk2.groups.io
> > > > Cc: Leif Lindholm <leif@nuviainc.com>; Sami Mujawar
> > > > <sami.mujawar@arm.com>; Yao, Jiewen <jiewen.yao@intel.com>;
> > Wang,
> > > > Jian J <jian.j.wang@intel.com>; Ard Biesheuvel <ardb@kernel.org>
> > > > Subject: Re: [edk2-devel] [PATCH v3 0/4] ArmPkg/SecurityPkg: Fixes for
> > > > ArmTrngLib/RngDxe
> > > >
> > > > Hello Jiewen, Jian,
> > > > Do these patches in this set look ok to you ?
> > > > - SecurityPkg/RngDxe: Correctly update mAvailableAlgoArrayCount
> > > > - SecurityPkg/RngDxe: Conditionally install EFI_RNG_PROTOCOL
> > > > - SecurityPkg/RngDxe: Fix Rng algo selection for Arm
> > > >
> > > > Regards,
> > > > Pierre
> > > >
> > > > On 2/10/23 10:26, PierreGondois via groups.io wrote:
> > > > > Hello Jiewen, Jian,
> > > > > Just a reminder in case this was forgotten,
> > > > > Regards,
> > > > > Pierre
> > > > >
> > > > > On 1/9/23 13:26, Pierre Gondois wrote:
> > > > >> Hello,
> > > > >> I was wondering if I should re-arrange the patch in any way/there was
> > any
> > > > >> concern with the patch set. The first patch of serie was taken, but the
> > > > other
> > > > >> ones are pending,
> > > > >>
> > > > >> Regards,
> > > > >> Pierre
> > > > >>
> > > > >> On 11/28/22 14:34, PierreGondois via groups.io wrote:
> > > > >>> Hello Ard,
> > > > >>>
> > > > >>> On 11/26/22 15:33, Ard Biesheuvel wrote:
> > > > >>>> On Thu, 24 Nov 2022 at 17:18, <Pierre.Gondois@arm.com> wrote:
> > > > >>>>>
> > > > >>>>> From: Pierre Gondois <pierre.gondois@arm.com>
> > > > >>>>>
> > > > >>>>> v1:
> > > > >>>>> - https://edk2.groups.io/g/devel/message/96356
> > > > >>>>> v2:
> > > > >>>>> - https://edk2.groups.io/g/devel/message/96434
> > > > >>>>> - Reformulate commit message.
> > > > >>>>> - Do not warn if no algorithm is found as the message
> > > > >>>>>       would be printed on non-Arm platforms.
> > > > >>>>> v3:
> > > > >>>>> - Add the following patches:
> > > > >>>>>       1. ArmPkg/ArmTrngLib: Remove ASSERTs in
> > > > ArmTrngLibConstructor()
> > > > >>>>>          Requested by Ard.
> > > > >>>>>          Cf https://edk2.groups.io/g/devel/message/96495
> > > > >>>>>       2. SecurityPkg/RngDxe: Conditionally install
> > EFI_RNG_PROTOCOL
> > > > >>>>>          Do not install EFI_RNG_PROTOCOL if no RNG algorithm is
> > > > available.
> > > > >>>>>          Cf. https://edk2.groups.io/g/devel/message/96494
> > > > >>>>>       3. SecurityPkg/RngDxe: Fix Rng algo selection for Arm
> > > > >>>>>          Coming from v2 patch being split.
> > > > >>>>>
> > > > >>>>> Some issues were found by Ard/Sami on the RngDxe/ArmTrngLib
> > after
> > > > >>>>> recent patches were merged. This patch serie intends to fix them.
> > > > >>>>>
> > > > >>>>> Pierre Gondois (4):
> > > > >>>>>       ArmPkg/ArmTrngLib: Remove ASSERTs in
> > ArmTrngLibConstructor()
> > > > >>>>
> > > > >>>> Thanks for the fixed
> > > > >>>>
> > > > >>>> Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
> > > > >>>>
> > > > >>>> I pushed this one as #3663 (pending CI verification atm)
> > > > >>>>
> > > > >>>>>       SecurityPkg/RngDxe: Correctly update
> > mAvailableAlgoArrayCount
> > > > >>>>>       SecurityPkg/RngDxe: Conditionally install EFI_RNG_PROTOCOL
> > > > >>>>>       SecurityPkg/RngDxe: Fix Rng algo selection for Arm
> > > > >>>>>
> > > > >>>>
> > > > >>>> The remaining code still looks a bit clunky to me. Can't we just
> > > > >>>> return an error from the library constructor of the library cannot
> > > > >>>> initialize due to a missing prerequisite?
> > > > >>>
> > > > >>> In RngDriverEntry(), GetAvailableAlgorithms() probe the available
> > > > >>> RNG algorithms. If there are none, then we return an error code.
> > > > >>> Otherwise we install EFI_RNG_PROTOCOL.
> > > > >>>
> > > > >>> I assume the prerequisite you a referring to is 'checking there is
> > > > >>> at least one available RNG algorithm that RngDxe can use', so if
> > > > >>> ArmTrngLib's constructor fails, we should not prevent RngDxe to be
> > > > >>> loaded (as the RngLib could be used for instance).
> > > > >>>
> > > > >>> Does it answer your question, or did I understand it incorrectly ?
> > > > >>>
> > > > >>> Regards,
> > > > >>> Pierre
> > > > >>>
> > > > >>>>
> > > > >>>>
> > > > >>>>>      ArmPkg/Library/ArmTrngLib/ArmTrngLib.c        |  5 -----
> > > > >>>>>      .../RandomNumberGenerator/RngDxe/ArmRngDxe.c  | 18
> > +++++---
> > > > ----------
> > > > >>>>>      .../RngDxe/Rand/RngDxe.c                      |  9 ++++++++-
> > > > >>>>>      .../RandomNumberGenerator/RngDxe/RngDxe.c     | 19
> > > > ++++++++++++++-----
> > > > >>>>>      4 files changed, 27 insertions(+), 24 deletions(-)
> > > > >>>>>
> > > > >>>>> --
> > > > >>>>> 2.25.1
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