回复: [edk2-devel] gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask and ExitBootServices


gaoliming
 

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

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