回复: [edk2-devel] [PATCH v2 1/1] ArmPkg: Fix uninitialised variable in ArmMmuStandaloneMmLib

["gaoliming" <gaoliming@byosoft.com.cn>]

Ard:
  This patch fixes the compiler build error. It is a bug fix. I am OK to merge it for this stable tag. 

Thanks
Liming
> -----邮件原件-----
> 发件人: Ard Biesheuvel <ardb@kernel.org>
> 发送时间: 2021年2月27日 2:46
> 收件人: Sughosh Ganu <sughosh.ganu@linaro.org>; Liming Gao (Byosoft
> address) <gaoliming@byosoft.com.cn>
> 抄送: devel@edk2.groups.io; Sami Mujawar <sami.mujawar@arm.com>; Ard
> Biesheuvel <ardb+tianocore@kernel.org>; Leif Lindholm <leif@nuviainc.com>;
> Matteo.Carlini@arm.com; Ben.Adderson@arm.com; nd <nd@arm.com>
> 主题: Re: [edk2-devel] [PATCH v2 1/1] ArmPkg: Fix uninitialised variable in
> ArmMmuStandaloneMmLib
> 
> On Fri, 26 Feb 2021 at 11:58, Sughosh Ganu <sughosh.ganu@linaro.org>
> wrote:
> >
> >
> > On Thu, 25 Feb 2021 at 22:41, Sami Mujawar <sami.mujawar@arm.com>
> wrote:
> >>
> >> The following patches added support for StandaloneMM using FF-A:
> >> 9da5ee116a28 ArmPkg: Allow FF-A calls to set memory region's attributes
> >> 0e43e02b9bd8 ArmPkg: Allow FF-A calls to get memory region's attributes
> >>
> >> However, in the error handling logic for the Get/Set Memory attributes,
> >> the CLANG compiler reports that a status variable could be used without
> >> initialisation. This issue is a false positive and is not seen with GCC.
> >>
> >> The Get/Set Memory attributes operation is atomic and therefore an
> >> FFA_INTERRUPT or FFA_SUCCESS response is not expected in response
> >> to FFA_MSG_SEND_DIRECT_REQ. So the remaining cases that could occur
> >> are:
> >>  - the target sends FFA_MSG_SEND_DIRECT_RESP with a success or
> >>    failure code.
> >>  or
> >>  - FFA_MSG_SEND_DIRECT_REQ transmission failure.
> >>
> >> Therefore,
> >>  - reorder the error handling conditions such that it prevents the
> >>    uninitialised variable issue being flagged by CLANG.
> >>  - move the repetitive code to a static helper function and add
> >>    documentation at the appropriate places.
> >>  - fix error handling in functions that invoke GetMemoryPermissions().
> >>
> >> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> >> ---
> >> The changes can be seen at:
> >>
> https://github.com/samimujawar/edk2/tree/1657_stmm_ffa_fix_unused_var
> _v2
> >
> >
> >  Tested the changes on the StandaloneMm image on the Qemu platform.
> >
> > Tested-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> >
> 
> Thanks. Sami, can you confirm that this patch fixes the CI failure I
> reported to you in private? If so, I intend to merge this during the
> freeze (assuming Liming is ok with that)