1 files changed, 75 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/utils/locking_allocator/locking_allocator.cpp b/comm/third_party/botan/src/lib/utils/locking_allocator/locking_allocator.cpp
new file mode 100644
index 0000000000..1c10c362b6
--- /dev/null
+++ b/comm/third_party/botan/src/lib/utils/locking_allocator/locking_allocator.cpp
@@ -0,0 +1,75 @@
+/*
+* Mlock Allocator
+* (C) 2012,2014,2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/locking_allocator.h>
+#include <botan/internal/os_utils.h>
+#include <botan/internal/mem_pool.h>
+
+namespace Botan {
+
+void* mlock_allocator::allocate(size_t num_elems, size_t elem_size)
+   {
+   if(!m_pool)
+      return nullptr;
+
+   const size_t n = num_elems * elem_size;
+   if(n / elem_size != num_elems)
+      return nullptr; // overflow!
+
+   return m_pool->allocate(n);
+   }
+
+bool mlock_allocator::deallocate(void* p, size_t num_elems, size_t elem_size) noexcept
+   {
+   if(!m_pool)
+      return false;
+
+   size_t n = num_elems * elem_size;
+
+   /*
+   We return nullptr in allocate if there was an overflow, so if an
+   overflow occurs here we know the pointer was not allocated by this pool.
+   */
+   if(n / elem_size != num_elems)
+      return false;
+
+   return m_pool->deallocate(p, n);
+   }
+
+mlock_allocator::mlock_allocator()
+   {
+   const size_t mem_to_lock = OS::get_memory_locking_limit();
+   const size_t page_size = OS::system_page_size();
+
+   if(mem_to_lock > 0 && mem_to_lock % page_size == 0)
+      {
+      m_locked_pages = OS::allocate_locked_pages(mem_to_lock / page_size);
+
+      if(m_locked_pages.size() > 0)
+         {
+         m_pool.reset(new Memory_Pool(m_locked_pages, page_size));
+         }
+      }
+   }
+
+mlock_allocator::~mlock_allocator()
+   {
+   if(m_pool)
+      {
+      m_pool.reset();
+      // OS::free_locked_pages scrubs the memory before free
+      OS::free_locked_pages(m_locked_pages);
+      }
+   }
+
+mlock_allocator& mlock_allocator::instance()
+   {
+   static mlock_allocator mlock;
+   return mlock;
+   }
+
+}