vm_manager: Add member function for checking a memory range adheres to certain attributes, permissions and states

2 files changed, 100 insertions, 0 deletions

diff --git a/src/core/hle/kernel/vm_manager.cpp b/src/core/hle/kernel/vm_manager.cpp
index 252f92df2..02504d750 100644
--- a/src/core/hle/kernel/vm_manager.cpp
+++ b/src/core/hle/kernel/vm_manager.cpp
@@ -592,6 +592,66 @@ void VMManager::ClearPageTable() {
               Memory::PageType::Unmapped);
 }
 
+VMManager::CheckResults VMManager::CheckRangeState(VAddr address, u64 size, MemoryState state_mask,
+                                                   MemoryState state, VMAPermission permission_mask,
+                                                   VMAPermission permissions,
+                                                   MemoryAttribute attribute_mask,
+                                                   MemoryAttribute attribute,
+                                                   MemoryAttribute ignore_mask) const {
+    auto iter = FindVMA(address);
+
+    // If we don't have a valid VMA handle at this point, then it means this is
+    // being called with an address outside of the address space, which is definitely
+    // indicative of a bug, as this function only operates on mapped memory regions.
+    DEBUG_ASSERT(IsValidHandle(iter));
+
+    const VAddr end_address = address + size - 1;
+    const MemoryAttribute initial_attributes = iter->second.attribute;
+    const VMAPermission initial_permissions = iter->second.permissions;
+    const MemoryState initial_state = iter->second.state;
+
+    while (true) {
+        // The iterator should be valid throughout the traversal. Hitting the end of
+        // the mapped VMA regions is unquestionably indicative of a bug.
+        DEBUG_ASSERT(IsValidHandle(iter));
+
+        const auto& vma = iter->second;
+
+        if (vma.state != initial_state) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        if ((vma.state & state_mask) != state) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        if (vma.permissions != initial_permissions) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        if ((vma.permissions & permission_mask) != permissions) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        if ((vma.attribute | ignore_mask) != (initial_attributes | ignore_mask)) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        if ((vma.attribute & attribute_mask) != attribute) {
+            return ERR_INVALID_ADDRESS_STATE;
+        }
+
+        if (end_address <= vma.EndAddress()) {
+            break;
+        }
+
+        ++iter;
+    }
+
+    return MakeResult(
+        std::make_tuple(initial_state, initial_permissions, initial_attributes & ~ignore_mask));
+}
+
 u64 VMManager::GetTotalMemoryUsage() const {
     LOG_WARNING(Kernel, "(STUBBED) called");
     return 0xF8000000;
diff --git a/src/core/hle/kernel/vm_manager.h b/src/core/hle/kernel/vm_manager.h
index e2614cd4c..9fa9a18fb 100644
--- a/src/core/hle/kernel/vm_manager.h
+++ b/src/core/hle/kernel/vm_manager.h
@@ -6,6 +6,7 @@
 
 #include <map>
 #include <memory>
+#include <tuple>
 #include <vector>
 #include "common/common_types.h"
 #include "core/hle/result.h"
@@ -256,6 +257,16 @@ struct PageInfo {
  * also backed by a single host memory allocation.
  */
 struct VirtualMemoryArea {
+    /// Gets the starting (base) address of this VMA.
+    VAddr StartAddress() const {
+        return base;
+    }
+
+    /// Gets the ending address of this VMA.
+    VAddr EndAddress() const {
+        return base + size - 1;
+    }
+
     /// Virtual base address of the region.
     VAddr base = 0;
     /// Size of the region.
@@ -517,6 +528,35 @@ private:
     /// Clears out the page table
     void ClearPageTable();
 
+    using CheckResults = ResultVal<std::tuple<MemoryState, VMAPermission, MemoryAttribute>>;
+
+    /// Checks if an address range adheres to the specified states provided.
+    ///
+    /// @param address         The starting address of the address range.
+    /// @param size            The size of the address range.
+    /// @param state_mask      The memory state mask.
+    /// @param state           The state to compare the individual VMA states against,
+    ///                        which is done in the form of: (vma.state & state_mask) != state.
+    /// @param permission_mask The memory permissions mask.
+    /// @param permissions     The permission to compare the individual VMA permissions against,
+    ///                        which is done in the form of:
+    ///                        (vma.permission & permission_mask) != permission.
+    /// @param attribute_mask  The memory attribute mask.
+    /// @param attribute       The memory attributes to compare the individual VMA attributes
+    ///                        against, which is done in the form of:
+    ///                        (vma.attributes & attribute_mask) != attribute.
+    /// @param ignore_mask     The memory attributes to ignore during the check.
+    ///
+    /// @returns If successful, returns a tuple containing the memory attributes
+    ///          (with ignored bits specified by ignore_mask unset), memory permissions, and
+    ///          memory state across the memory range.
+    /// @returns If not successful, returns ERR_INVALID_ADDRESS_STATE.
+    ///
+    CheckResults CheckRangeState(VAddr address, u64 size, MemoryState state_mask, MemoryState state,
+                                 VMAPermission permission_mask, VMAPermission permissions,
+                                 MemoryAttribute attribute_mask, MemoryAttribute attribute,
+                                 MemoryAttribute ignore_mask) const;
+
     /**
      * A map covering the entirety of the managed address space, keyed by the `base` field of each
      * VMA. It must always be modified by splitting or merging VMAs, so that the invariant