Kernel: Stop trying to write unmapped Process regions into CoreDumps

If we crashed in the middle of mapping in Regions, some of the regions
may not have a page directory yet, and will result in a crash when
Region::remap() is called.

Author: IdanHo

Kernel/Coredump.cpp

@@ -186,6 +186,10 @@ ErrorOr<void> Coredump::write_regions()
         if (region->access() == Memory::Region::Access::None)
             continue;
 
+        // If we crashed in the middle of mapping in Regions, they do not have a page directory yet, and will crash on a remap() call
+        if (!region->is_mapped())
+            continue;
+
         region->set_readable(true);
         region->remap();
 

Kernel/Memory/Region.h

@@ -188,6 +188,8 @@ class Region final
 
     void remap();
 
+    [[nodiscard]] bool is_mapped() const { return m_page_directory != nullptr; }
+
     void clear_to_zero();
 
     [[nodiscard]] bool is_syscall_region() const { return m_syscall_region; }