I think the original patch is fine. StackBase is already checked by using ASSERT before. > + ASSERT ((StackBase & EFI_PAGE_MASK) == 0);
MemMap entry must be page aligned. No additional check is required here. Thank you Yao Jiewen > -----Original Message----- > From: Wang, Jian J > Sent: Wednesday, March 7, 2018 11:40 AM > To: Ni, Ruiyu <ruiyu...@intel.com>; Wu, Hao A <hao.a...@intel.com>; > edk2-devel@lists.01.org > Cc: Zeng, Star <star.z...@intel.com>; Dong, Eric <eric.d...@intel.com>; Yao, > Jiewen <jiewen....@intel.com> > Subject: RE: [PATCH v2 0/2] Resolve feature conflict between NX and Stack > guard > > > > Regards, > Jian > > > > -----Original Message----- > > From: Ni, Ruiyu > > Sent: Wednesday, March 07, 2018 11:17 AM > > To: Wu, Hao A <hao.a...@intel.com>; edk2-devel@lists.01.org > > Cc: Wang, Jian J <jian.j.w...@intel.com>; Zeng, Star <star.z...@intel.com>; > > Dong, Eric <eric.d...@intel.com>; Yao, Jiewen <jiewen....@intel.com> > > 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 <jian.j.w...@intel.com> > > > Cc: Star Zeng <star.z...@intel.com> > > > Cc: Eric Dong <eric.d...@intel.com> > > > Cc: Jiewen Yao <jiewen....@intel.com> > > > Cc: Ruiyu Ni <ruiyu...@intel.com> > > > > > > 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 edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel