Kernel: Add RegionTree::find_region_containing(address or range)

Let's encapsulate looking up regions so clients don't have to dig into
RegionTree internals.

4 files changed, 25 insertions, 15 deletions

diff --git a/Kernel/Memory/AddressSpace.cpp b/Kernel/Memory/AddressSpace.cpp
index 5e84decbdd..50cd70eb73 100644
--- a/Kernel/Memory/AddressSpace.cpp
+++ b/Kernel/Memory/AddressSpace.cpp
@@ -250,12 +250,7 @@ Region* AddressSpace::find_region_from_range(VirtualRange const& range)
 
 Region* AddressSpace::find_region_containing(VirtualRange const& range)
 {
-    SpinlockLocker lock(m_lock);
-    SpinlockLocker tree_locker(m_region_tree.get_lock());
-    auto* candidate = m_region_tree.regions().find_largest_not_above(range.base().get());
-    if (!candidate)
-        return nullptr;
-    return (*candidate).range().contains(range) ? candidate : nullptr;
+    return m_region_tree.find_region_containing(range);
 }
 
 ErrorOr<Vector<Region*>> AddressSpace::find_regions_intersecting(VirtualRange const& range)
diff --git a/Kernel/Memory/MemoryManager.cpp b/Kernel/Memory/MemoryManager.cpp
index 9384fa6a98..2934655b75 100644
--- a/Kernel/Memory/MemoryManager.cpp
+++ b/Kernel/Memory/MemoryManager.cpp
@@ -658,18 +658,12 @@ UNMAP_AFTER_INIT void MemoryManager::initialize(u32 cpu)
     }
 }
 
-Region* MemoryManager::kernel_region_from_vaddr(VirtualAddress vaddr)
+Region* MemoryManager::kernel_region_from_vaddr(VirtualAddress address)
 {
-    if (is_user_address(vaddr))
+    if (is_user_address(address))
         return nullptr;
 
-    SpinlockLocker lock(s_mm_lock);
-    SpinlockLocker tree_locker(MM.m_region_tree.get_lock());
-
-    auto* region = MM.m_region_tree.regions().find_largest_not_above(vaddr.get());
-    if (!region || !region->contains(vaddr))
-        return nullptr;
-    return region;
+    return MM.region_tree().find_region_containing(address);
 }
 
 Region* MemoryManager::find_user_region_from_vaddr_no_lock(AddressSpace& space, VirtualAddress vaddr)
diff --git a/Kernel/Memory/RegionTree.cpp b/Kernel/Memory/RegionTree.cpp
index ed0baa952c..5736a56aa1 100644
--- a/Kernel/Memory/RegionTree.cpp
+++ b/Kernel/Memory/RegionTree.cpp
@@ -170,4 +170,22 @@ bool RegionTree::remove(Region& region)
     return m_regions.remove(region.range().base().get());
 }
 
+Region* RegionTree::find_region_containing(VirtualAddress address)
+{
+    SpinlockLocker locker(m_lock);
+    auto* region = m_regions.find_largest_not_above(address.get());
+    if (!region || !region->contains(address))
+        return nullptr;
+    return region;
+}
+
+Region* RegionTree::find_region_containing(VirtualRange range)
+{
+    SpinlockLocker lock(m_lock);
+    auto* region = m_regions.find_largest_not_above(range.base().get());
+    if (!region || !region->contains(range))
+        return nullptr;
+    return region;
+}
+
 }
diff --git a/Kernel/Memory/RegionTree.h b/Kernel/Memory/RegionTree.h
index d55b52affb..339fc6fd3c 100644
--- a/Kernel/Memory/RegionTree.h
+++ b/Kernel/Memory/RegionTree.h
@@ -54,6 +54,9 @@ public:
 
     bool remove(Region&);
 
+    Region* find_region_containing(VirtualAddress);
+    Region* find_region_containing(VirtualRange);
+
 private:
     ErrorOr<VirtualRange> allocate_range_anywhere(size_t size, size_t alignment = PAGE_SIZE);
     ErrorOr<VirtualRange> allocate_range_specific(VirtualAddress base, size_t size);