Commits on Nov 8, 2024

1. ArmPkg: ArmMmuLib: Pre-Allocate Page Table Memory …

   Allocating memory when memory protection is active can cause the below
   infinite loop:
   
   1. gCpu->SetMemoryAttributes(EFI_MEMORY_RO)
   2. ArmSetMemoryAttributes ()
   3. SetMemoryRegionAttribute()
   4. UpdateRegionMapping()
   5. UpdateRegionMappingRecursive()
   6. AllocatePages() -> Need memory for a translation table entry
   7. CoreAllocatePages()
   8. ApplyMemoryProtectionPolicy() -> Policy says new page should be XN
   9. gCpu->SetMemoryAttributes()
   10. Back to 3
   
   To fix this previously, CpuDxe would update conventional memory to be XN
   prior to installing the CpuArch protocol. However, when we transition to
   setting EFI_MEMORY_RP on free memory, this will no longer work.
   
   This PR updates ArmMmuLib to reserve page table memory for allocation
   during table spits to prevent the infinite loop.
   
   It also updates the consumers of ArmMmuLib to consume the PEI version
   of the lib in the same commit so as to not break them.
   
   Continuous-integration-options: PatchCheck.ignore-multi-package
   
   Signed-off-by: Oliver Smith-Denny <[email protected]>

   

   TaylorBeebe authored and os-d committed Nov 8, 2024
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