1 /*
2 * Copyright (C) 2023 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "berberis/runtime/execute_guest.h"
18
19 #include "berberis/base/checks.h"
20 #include "berberis/base/config.h"
21 #include "berberis/base/tracing.h"
22 #include "berberis/guest_os_primitives/guest_thread.h"
23 #include "berberis/guest_state/guest_addr.h"
24 #include "berberis/guest_state/guest_state_opaque.h"
25 #include "berberis/runtime_primitives/runtime_library.h"
26 #include "berberis/runtime_primitives/translation_cache.h"
27
28 namespace berberis {
29
ExecuteGuest(ThreadState * state)30 void ExecuteGuest(ThreadState* state) {
31 CHECK(state);
32 GuestThread* thread = GetGuestThread(*state);
33 CHECK(thread);
34 CHECK_EQ(state, thread->state());
35
36 TranslationCache* cache = TranslationCache::GetInstance();
37
38 for (;;) {
39 auto pc = GetInsnAddr(GetCPUState(*state));
40
41 if (ArePendingSignalsPresent(*state)) {
42 thread->ProcessPendingSignals();
43 // Signal handler can modify control flow, e.g. to recover from segfault.
44 if (pc != GetInsnAddr(GetCPUState(*state))) {
45 TRACE("PC modified by signal handler: old=%p new=%p",
46 ToHostAddr<void>(pc),
47 ToHostAddr<void>(GetInsnAddr(GetCPUState(*state))));
48 pc = GetInsnAddr(GetCPUState(*state));
49 }
50 }
51
52 auto code = cache->GetHostCodePtr(pc)->load();
53 if (code == kEntryStop) {
54 break;
55 }
56
57 if (config::kTraceGeneratedCode) {
58 TRACE("RunGeneratedCode @ 0x%zx", pc);
59 }
60
61 // ATTENTION: this should be the only place to run translated code!
62 berberis_RunGeneratedCode(state, code);
63 }
64 }
65
66 } // namespace berberis
67