mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-22 23:50:19 +00:00
4b16ac0034
Anonymous VM objects should never have null entries in their physical page list. Instead, "empty" or untouched pages should refer to the shared zero page. Fixes #1237.
90 lines
2.7 KiB
C++
90 lines
2.7 KiB
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <Kernel/VM/MemoryManager.h>
|
|
#include <Kernel/VM/PhysicalPage.h>
|
|
#include <Kernel/VM/PurgeableVMObject.h>
|
|
|
|
namespace Kernel {
|
|
|
|
NonnullRefPtr<PurgeableVMObject> PurgeableVMObject::create_with_size(size_t size)
|
|
{
|
|
return adopt(*new PurgeableVMObject(size));
|
|
}
|
|
|
|
PurgeableVMObject::PurgeableVMObject(size_t size)
|
|
: AnonymousVMObject(size)
|
|
{
|
|
}
|
|
|
|
PurgeableVMObject::PurgeableVMObject(const PurgeableVMObject& other)
|
|
: AnonymousVMObject(other)
|
|
{
|
|
}
|
|
|
|
PurgeableVMObject::~PurgeableVMObject()
|
|
{
|
|
}
|
|
|
|
NonnullRefPtr<VMObject> PurgeableVMObject::clone()
|
|
{
|
|
return adopt(*new PurgeableVMObject(*this));
|
|
}
|
|
|
|
int PurgeableVMObject::purge()
|
|
{
|
|
LOCKER(m_paging_lock);
|
|
return purge_impl();
|
|
}
|
|
|
|
int PurgeableVMObject::purge_with_interrupts_disabled(Badge<MemoryManager>)
|
|
{
|
|
ASSERT_INTERRUPTS_DISABLED();
|
|
if (m_paging_lock.is_locked())
|
|
return 0;
|
|
return purge_impl();
|
|
}
|
|
|
|
int PurgeableVMObject::purge_impl()
|
|
{
|
|
if (!m_volatile)
|
|
return 0;
|
|
int purged_page_count = 0;
|
|
for (size_t i = 0; i < m_physical_pages.size(); ++i) {
|
|
if (m_physical_pages[i])
|
|
++purged_page_count;
|
|
m_physical_pages[i] = MM.shared_zero_page();
|
|
}
|
|
m_was_purged = true;
|
|
|
|
for_each_region([&](auto& region) {
|
|
region.remap();
|
|
});
|
|
|
|
return purged_page_count;
|
|
}
|
|
|
|
}
|