Kernel: No lock validate_user_stack variant, switch to Space as argument

The entire process is not needed, just require the user to pass in the
Space. Also provide no_lock variant to use when you already have the
VM/Space lock acquired, to avoid unnecessary recursive spinlock
acquisitions.

1 files changed, 11 insertions, 3 deletions

diff --git a/Kernel/VM/MemoryManager.cpp b/Kernel/VM/MemoryManager.cpp
index 76607faf4e..30f8a54fc7 100644
--- a/Kernel/VM/MemoryManager.cpp
+++ b/Kernel/VM/MemoryManager.cpp
@@ -1032,15 +1032,23 @@ void MemoryManager::unquickmap_page()
     mm_data.m_quickmap_in_use.unlock(mm_data.m_quickmap_prev_flags);
 }
 
-bool MemoryManager::validate_user_stack(Process const& process, VirtualAddress vaddr) const
+bool MemoryManager::validate_user_stack_no_lock(Space& space, VirtualAddress vaddr) const
 {
+    VERIFY(space.get_lock().own_lock());
+
     if (!is_user_address(vaddr))
         return false;
-    ScopedSpinLock lock(s_mm_lock);
-    auto* region = find_user_region_from_vaddr(const_cast<Process&>(process).space(), vaddr);
+
+    auto* region = find_user_region_from_vaddr(space, vaddr);
     return region && region->is_user() && region->is_stack();
 }
 
+bool MemoryManager::validate_user_stack(Space& space, VirtualAddress vaddr) const
+{
+    ScopedSpinLock lock(space.get_lock());
+    return validate_user_stack_no_lock(space, vaddr);
+}
+
 void MemoryManager::register_vmobject(VMObject& vmobject)
 {
     ScopedSpinLock lock(s_mm_lock);