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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <Kernel/Memory/AnonymousVMObject.h>
8#include <Kernel/Memory/InodeVMObject.h>
9#include <Kernel/Memory/MemoryManager.h>
10#include <Kernel/Process.h>
11
12namespace Kernel {
13
14ErrorOr<FlatPtr> Process::sys$purge(int mode)
15{
16 VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
17 TRY(require_no_promises());
18 auto credentials = this->credentials();
19 if (!credentials->is_superuser())
20 return EPERM;
21 size_t purged_page_count = 0;
22 if (mode & PURGE_ALL_VOLATILE) {
23 Vector<NonnullLockRefPtr<Memory::AnonymousVMObject>> vmobjects;
24 {
25 ErrorOr<void> result;
26 Memory::MemoryManager::for_each_vmobject([&](auto& vmobject) {
27 if (vmobject.is_anonymous()) {
28 // In the event that the append fails, only attempt to continue
29 // the purge if we have already appended something successfully.
30 if (auto append_result = vmobjects.try_append(static_cast<Memory::AnonymousVMObject&>(vmobject)); append_result.is_error() && vmobjects.is_empty()) {
31 result = append_result.release_error();
32 return IterationDecision::Break;
33 }
34 }
35 return IterationDecision::Continue;
36 });
37
38 if (result.is_error())
39 return result.release_error();
40 }
41 for (auto& vmobject : vmobjects) {
42 purged_page_count += vmobject->purge();
43 }
44 }
45 if (mode & PURGE_ALL_CLEAN_INODE) {
46 Vector<NonnullLockRefPtr<Memory::InodeVMObject>> vmobjects;
47 {
48 ErrorOr<void> result;
49 Memory::MemoryManager::for_each_vmobject([&](auto& vmobject) {
50 if (vmobject.is_inode()) {
51 // In the event that the append fails, only attempt to continue
52 // the purge if we have already appended something successfully.
53 if (auto append_result = vmobjects.try_append(static_cast<Memory::InodeVMObject&>(vmobject)); append_result.is_error() && vmobjects.is_empty()) {
54 result = append_result.release_error();
55 return IterationDecision::Break;
56 }
57 }
58 return IterationDecision::Continue;
59 });
60
61 if (result.is_error())
62 return result.release_error();
63 }
64 for (auto& vmobject : vmobjects) {
65 purged_page_count += vmobject->release_all_clean_pages();
66 }
67 }
68 return purged_page_count;
69}
70
71}