[edk2-devel] [PATCH 1/2] MdeModulePkg/dec: update the PcdCpuStackGuard property

[Jeff Fan]

On 32bit protectd mode, is there any impact if PcdCpuStackGuard is set to TRUE?  Even thers is no page table enabling at that time.

Best Regards,
Jeff



fanjianfeng at byosoft.com.cn
 
From: Chen, Gang C
Date: 2022-04-11 22:51
To: Ni, Ray; devel at edk2.groups.io; Liu, Shuo
CC: Jiang, Guomin; Bi, Dandan; Zhang, Di; Wang, Jian J; Gao, Liming
Subject: Re: [edk2-devel] [PATCH 1/2] MdeModulePkg/dec: update the PcdCpuStackGuard property
This impact of this change is not as simple as what the patch does.
-->You're correct, that's why the PATCH 2/2 removed the check in AP.
 
Why cannot FSP API and Dispatch mode use the same setting? (either enabled or disabled)
-->For example, in coreboot, it's 32-bit, so there is no Paging needed. In this case, it needs to disable it for FSP API mode. But this feature is needed for Dispatch mode. 
 
@Liu, Shuo, if any information is wrong or missed, please correct me. Thanks.
 
Best Regards
Gang
 
-----Original Message-----
From: Ni, Ray <ray.ni at intel.com> 
Sent: Monday, April 11, 2022 9:55 PM
To: devel at edk2.groups.io; Chen, Gang C <gang.c.chen at intel.com>
Cc: Jiang, Guomin <guomin.jiang at intel.com>; Bi, Dandan <dandan.bi at intel.com>; Zhang, Di <di.zhang at intel.com>; Wang, Jian J <jian.j.wang at intel.com>; Gao, Liming <gaoliming at byosoft.com.cn>
Subject: RE: [edk2-devel] [PATCH 1/2] MdeModulePkg/dec: update the PcdCpuStackGuard property
 
FixedAtBuild PCD can be accessed at any time from any CPU.
But dynamic PCD can only be accessed from BSP and after PCD database is initialized.
 
This impact of this change is not as simple as what the patch does.
 
Why cannot FSP API and Dispatch mode use the same setting? (either enabled or disabled)
 
Thanks,
Ray
 
> -----Original Message-----
> From: devel at edk2.groups.io <devel at edk2.groups.io> On Behalf Of Chen, 
> Gang C
> Sent: Monday, April 11, 2022 6:14 PM
> To: devel at edk2.groups.io
> Cc: Jiang, Guomin <guomin.jiang at intel.com>; Bi, Dandan 
> <dandan.bi at intel.com>; Zhang, Di <di.zhang at intel.com>; Wang, Jian J 
> <jian.j.wang at intel.com>; Gao, Liming <gaoliming at byosoft.com.cn>
> Subject: [edk2-devel] [PATCH 1/2] MdeModulePkg/dec: update the 
> PcdCpuStackGuard property
> 
> Update the PcdCpuStackGuard from PcdsFixedAtBuild to PcdsDynamicEx for 
> the requirement to set different value in FSP API mode and FSP 
> Dispatch mode.
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3897
> 
> Cc: Jian J Wang <jian.j.wang at intel.com>
> Cc: Liming Gao <gaoliming at byosoft.com.cn>
> Cc: devel at edk2.groups.io
> 
> Signed-off-by: Gang Chen <gang.c.chen at intel.com>
> ---
>  MdeModulePkg/MdeModulePkg.dec | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/MdeModulePkg/MdeModulePkg.dec 
> b/MdeModulePkg/MdeModulePkg.dec index 463e889e9a..72e7e2eced 100644
> --- a/MdeModulePkg/MdeModulePkg.dec
> +++ b/MdeModulePkg/MdeModulePkg.dec
> @@ -1070,13 +1070,6 @@
>    # @Prompt The Heap Guard feature mask
>    
> gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask|0x0|UINT8|0x30
> 001054
> 
> -  ## Indicates if UEFI Stack Guard will be enabled.
> -  #  If enabled, stack overflow in UEFI can be caught, preventing chaotic consequences.<BR><BR>
> -  #   TRUE  - UEFI Stack Guard will be enabled.<BR>
> -  #   FALSE - UEFI Stack Guard will be disabled.<BR>
> -  # @Prompt Enable UEFI Stack Guard.
> -  
> gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard|FALSE|BOOLEAN|0x300010
> 55
> -
>  [PcdsFixedAtBuild, PcdsPatchableInModule]
>    ## Dynamic type PCD can be registered callback function for Pcd setting action.
>    #  PcdMaxPeiPcdCallBackNumberPerPcdEntry indicates the maximum 
> number of callback function @@ -2079,6 +2072,13 @@
>    # @Prompt Enable PCIe Resizable BAR Capability support.
>    
> gEfiMdeModulePkgTokenSpaceGuid.PcdPcieResizableBarSupport|FALSE|BOOLEA
> N|0x10000024
> 
> +  ## Indicates if UEFI Stack Guard will be enabled.
> +  #  If enabled, stack overflow in UEFI can be caught, preventing chaotic consequences.<BR><BR>
> +  #   TRUE  - UEFI Stack Guard will be enabled.<BR>
> +  #   FALSE - UEFI Stack Guard will be disabled.<BR>
> +  # @Prompt Enable UEFI Stack Guard.
> +  
> + gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard|FALSE|BOOLEAN|0x0001
> + 0025
> +
>  [PcdsPatchableInModule]
>    ## Specify memory size with page number for PEI code when
>    #  Loading Module at Fixed Address feature is enabled.
> --
> 2.35.1
> 
> 
> 
> 
> 
 
 
 

 
 
 


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#88761): https://edk2.groups.io/g/devel/message/88761
Mute This Topic: https://groups.io/mt/90391665/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/edk2-devel-archive/attachments/20220412/44c45880/attachment-0001.htm>