回复: [edk2-devel] 回复: [PATCH] MdeModulePkg: Fix runtime panic in ValidateSetVariable()

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

PR https://github.com/tianocore/edk2/pull/1148 is created. 

Thanks
Liming

> -----邮件原件-----
> 发件人: bounce+27952+68010+4905953+8761045@groups.io
> <bounce+27952+68010+4905953+8761045@groups.io> 代表 gaoliming
> 发送时间: 2020年11月26日 9:23
> 收件人: 'Laszlo Ersek' <lersek@redhat.com>; jejb@linux.ibm.com
> 抄送: devel@edk2.groups.io; 'Bret Barkelew' <brbarkel@microsoft.com>;
> 'Ard Biesheuvel (ARM address)' <ard.biesheuvel@arm.com>; 'Hao A Wu'
> <hao.a.wu@intel.com>; 'Jian J Wang' <jian.j.wang@intel.com>
> 主题: [edk2-devel] 回复: [PATCH] MdeModulePkg: Fix runtime panic in
> ValidateSetVariable()
> 
> Laszlo and James:
>   Thanks for your root cause. The fix is clear. It works on runtime version and
> smm version. Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
> 
>   I agree to merge this hot fix for this stable tag 202011. I will add Laszlo tag
> and update subject title when I merge this patch.
> 
> Thanks
> Liming
> > -----邮件原件-----
> > 发件人: Laszlo Ersek <lersek@redhat.com>
> > 发送时间: 2020年11月26日 5:01
> > 收件人: jejb@linux.ibm.com; Liming Gao (Byosoft address)
> > <gaoliming@byosoft.com.cn>
> > 抄送: devel@edk2.groups.io; Bret Barkelew <brbarkel@microsoft.com>;
> Ard
> > Biesheuvel (ARM address) <ard.biesheuvel@arm.com>; Hao A Wu
> > <hao.a.wu@intel.com>; Jian J Wang <jian.j.wang@intel.com>
> > 主题: Re: [PATCH] MdeModulePkg: Fix runtime panic in
> ValidateSetVariable()
> >
> > On 11/25/20 21:13, James Bottomley wrote:
> > > The current variable policy is allocated by AllocatePool(), which is
> > > boot time only.  This means that if you do any variable setting in the
> > > runtime, the policy has been freed.  Ordinarily this isn't detected
> > > because freed memory is still there, but when you boot the Linux
> > > kernel, it's been remapped so the actual memory no longer exists in
> > > the memory map causing a page fault.
> > >
> > > Fix this by making it AllocateRuntimePool().  For SMM drivers, the
> > > platform DSC is responsible for resolving the MemoryAllocationLib
> > > class to the SmmMemoryAllocationLib instance. In the
> > > SmmMemoryAllocationLib instance, AllocatePool() and
> > > AllocateRuntimePool() are implemented identically. Therefore this
> > > change is a no-op when the RegisterVariablePolicy() function is built
> > > into an SMM driver. The fix affects runtime DXE drivers only.
> > >
> > > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3092
> > > Signed-off-by: James Bottomley <jejb@linux.ibm.com>
> > > ---
> > >  MdeModulePkg/Library/VariablePolicyLib/VariablePolicyLib.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyLib.c
> > b/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyLib.c
> > > index 5029ddb96adb..12944ac7ea81 100644
> > > --- a/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyLib.c
> > > +++ b/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyLib.c
> > > @@ -411,7 +411,7 @@ RegisterVariablePolicy (
> > >      }
> > >
> > >      // Reallocate and copy the table.
> > > -    NewTable = AllocatePool( NewSize );
> > > +    NewTable = AllocateRuntimePool( NewSize );
> > >      if (NewTable == NULL) {
> > >        return EFI_OUT_OF_RESOURCES;
> > >      }
> > >
> >
> > (1) CC'ing Jian and Hao:
> >
> > $ python BaseTools/Scripts/GetMaintainer.py \
> >     -l MdeModulePkg/Library/VariablePolicyLib/VariablePolicyLib.c
> >
> >   Jian J Wang <jian.j.wang@intel.com>
> >   Hao A Wu <hao.a.wu@intel.com>
> >   Liming Gao <gaoliming@byosoft.com.cn>
> >   devel@edk2.groups.io
> >
> >
> > (2) My feedback:
> >
> > Fixes: 355b181f74050cdf2f09b1755c1a5ee4affb1faf
> > Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> > Tested-by: Laszlo Ersek <lersek@redhat.com>
> >
> > (I tested the actual bugfix with SMM-less OVMF.  I also
> > regression-tested the patch, namely with SMM OVMF, and ArmVirtQemu
> too.)
> >
> >
> > (3) I suggest updating the subject line as follows:
> >
> >   MdeModulePkg/VariablePolicyLib: Fix runtime panic in
> > ValidateSetVariable()
> >
> > 74 characters, so it's not overlong.
> >
> > No need to repost because of this.
> >
> >
> > Liming, can you please pick up my feedback tags from (2), in addition to
> > your own review, and refresh the subject as requested in (3), and then
> > merge this patch -- before releasing edk2-stable202011?
> >
> > Thank you all,
> > Laszlo
> 
> 
> 
> 
> 
> 
>