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* gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask and ExitBootServices
@ 2020-08-27  0:33 Andrew Fish
  2020-08-27  1:38 ` 回复: [edk2-devel] " gaoliming
  0 siblings, 1 reply; 2+ messages in thread
From: Andrew Fish @ 2020-08-27  0:33 UTC (permalink / raw)
  To: edk2-devel-groups-io

I think I might have found a case when grub calls ExitBootServices, PcdNullPointerDetectionPropertyMask is TRUE, and grub decided to allocate memory in the guard area….

Is there any code to turn off PcdNullPointerDetectionPropertyMask at ExitBootServices time?

Seems like MemoryProtectionExitBootServicesCallback() should also turn off PcdNullPointerDetectionPropertyMask?

Thanks,

Andrew Fish

^ permalink raw reply	[flat|nested] 2+ messages in thread
* 回复: [edk2-devel] gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask and ExitBootServices
  2020-08-27  0:33 gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask and ExitBootServices Andrew Fish
@ 2020-08-27  1:38 ` gaoliming
  0 siblings, 0 replies; 2+ messages in thread
From: gaoliming @ 2020-08-27  1:38 UTC (permalink / raw)
  To: devel, afish

Fish:
  If PcdNullPointerDetectionPropertyMask BIT7 is set, it will be disabled on EndOfDxe. Do you mean to always turn off it on ExitBootServices? But, after ExitBootSerivces, there should be no memory allocation. 

Thanks
Liming
> -----邮件原件-----
> 发件人: bounce+27952+64665+4905953+8761045@groups.io
> <bounce+27952+64665+4905953+8761045@groups.io> 代表 Andrew Fish
> via groups.io
> 发送时间: 2020年8月27日 8:34
> 收件人: edk2-devel-groups-io <devel@edk2.groups.io>
> 主题: [edk2-devel]
> gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
> and ExitBootServices
> 
> I think I might have found a case when grub calls ExitBootServices,
> PcdNullPointerDetectionPropertyMask is TRUE, and grub decided to allocate
> memory in the guard area….
> 
> Is there any code to turn off PcdNullPointerDetectionPropertyMask at
> ExitBootServices time?
> 
> Seems like MemoryProtectionExitBootServicesCallback() should also turn off
> PcdNullPointerDetectionPropertyMask?
> 
> Thanks,
> 
> Andrew Fish
> 




^ permalink raw reply	[flat|nested] 2+ messages in thread
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2020-08-27  0:33 gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask and ExitBootServices Andrew Fish
2020-08-27  1:38 ` 回复: [edk2-devel] " gaoliming

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