Regards, Jian
> -----Original Message----- > From: Ni, Ruiyu > Sent: Wednesday, March 07, 2018 11:17 AM > To: Wu, Hao A <[email protected]>; [email protected] > Cc: Wang, Jian J <[email protected]>; Zeng, Star <[email protected]>; > Dong, Eric <[email protected]>; Yao, Jiewen <[email protected]> > Subject: Re: [PATCH v2 0/2] Resolve feature conflict between NX and Stack > guard > > On 3/6/2018 9:33 PM, Hao Wu wrote: > > V2 changes: > > > > A. Use Hoblib APIs to get the base of stack from Hob. > > B. Remove unnecessary local variable used in function > > InitializeDxeNxMemoryProtectionPolicy(). > > > > V1 history: > > > > If enabled, NX memory protection feature will mark some types of active > > memory as NX (non-executable), which includes the first page of the stack. > > This will overwrite the attributes of the first page of the stack if the > > stack guard feature is also enabled. > > > > The series will override the attributes setting to the first page of the > > stack by adding back the 'EFI_MEMORY_RP' attribute when the stack guard > > feature is enabled. > > > > Cc: Jian J Wang <[email protected]> > > Cc: Star Zeng <[email protected]> > > Cc: Eric Dong <[email protected]> > > Cc: Jiewen Yao <[email protected]> > > Cc: Ruiyu Ni <[email protected]> > > > > Hao Wu (2): > > MdeModulePkg/Core: Refine handling NULL detection in NX setting > > MdeModulePkg/Core: Fix feature conflict between NX and Stack guard > > > > MdeModulePkg/Core/Dxe/DxeMain.inf | 4 +- > > MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c | 74 > +++++++++++++++++++++++---- > > 2 files changed, 67 insertions(+), 11 deletions(-) > > > > if (MemoryMapEntry->PhysicalStart == 0 && > PcdGet8 (PcdNullPointerDetectionPropertyMask) != 0) { > > ASSERT (MemoryMapEntry->NumberOfPages > 0); > // > // Add EFI_MEMORY_RP attribute for page 0 if NULL pointer > detection is > // enabled. > // > [Ray] 1. I prefer to move the above comments before the "if (...)". > > SetUefiImageMemoryAttributes ( > 0, > EFI_PAGES_TO_SIZE (1), > EFI_MEMORY_RP | Attributes); > } > > if (StackBase != 0 && > (StackBase >= MemoryMapEntry->PhysicalStart && > StackBase < MemoryMapEntry->PhysicalStart + > LShiftU64 (MemoryMapEntry->NumberOfPages, > EFI_PAGE_SHIFT)) && > PcdGetBool (PcdCpuStackGuard)) { > > // > // Add EFI_MEMORY_RP attribute for the first page of the stack > if stack > // guard is enabled. > // > SetUefiImageMemoryAttributes ( > StackBase, > EFI_PAGES_TO_SIZE (1), > EFI_MEMORY_RP | Attributes); > [Ray] 2. The StackBase is directly used here. So do we need to check > whether it's page aligned? Do we need to check whether the range > [StackBase, StackBase + 4KB) is inside the MemoryMapEntry? > } If PcdCpuStackGuard is TRUE, I think the owner who allocates memory for StackBase should make sure all the conditions you mentioned, but not here. > > -- > Thanks, > Ray _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
