x86: fix pte corruption when setting large regions

We need a copy of the flags field for ever PTE we are
updating, we can't just keep OR-ing in the address
field.

Fixes issues seen when setting flags for memory regions
larger than a page.

Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

arch/x86/core/x86_mmu.c

@@ -195,6 +195,7 @@ void _x86_mmu_set_flags(struct x86_mmu_pdpt *pdpt, void *ptr,
 	}
 
 	while (size != 0) {
+		x86_page_entry_data_t cur_flags = flags;
 
 		/* TODO we're not generating 2MB entries at the moment */
 		__ASSERT(X86_MMU_GET_PDE(pdpt, addr)->ps != 1, "2MB PDE found");
@@ -206,10 +207,10 @@ void _x86_mmu_set_flags(struct x86_mmu_pdpt *pdpt, void *ptr,
 		 */
 		if (((mask & MMU_PTE_P_MASK) != 0) &&
 		    ((flags & MMU_ENTRY_PRESENT) != 0)) {
-			flags |= addr;
+			cur_flags |= addr;
 		}
 
-		pte->value = (pte->value & ~mask) | flags;
+		pte->value = (pte->value & ~mask) | cur_flags;
 		tlb_flush_page((void *)addr);
 
 		size -= MMU_PAGE_SIZE;