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_primitives/host_function_wrapper_impl.h"
18
19 #include "berberis/assembler/machine_code.h"
20 #include "berberis/base/tracing.h"
21 #include "berberis/code_gen_lib/gen_adaptor.h"
22 #include "berberis/guest_state/guest_addr.h"
23 #include "berberis/runtime_primitives/checks.h"
24 #include "berberis/runtime_primitives/code_pool.h"
25 #include "berberis/runtime_primitives/host_code.h"
26 #include "berberis/runtime_primitives/translation_cache.h"
27
28 namespace berberis {
29
MakeTrampolineCallable(GuestAddr pc,bool is_host_func,TrampolineFunc func,HostCode arg,const char * name)30 void MakeTrampolineCallable(GuestAddr pc,
31 bool is_host_func,
32 TrampolineFunc func,
33 HostCode arg,
34 const char* name) {
35 if (!pc) {
36 return;
37 }
38
39 // Guest address for wrapped host function must be properly aligned, otherwise
40 // the guest simply can't encode it to call by immediate. We are unlikely affected,
41 // as calling an external symbol by immediate requires text relocation, but
42 // we should still issue an error.
43 if (!IsProgramCounterProperlyAlignedForArch(pc)) {
44 TRACE("address %p of wrapped host function '%s' is not aligned", ToHostAddr<void>(pc), name);
45 }
46 TranslationCache* cache = TranslationCache::GetInstance();
47 GuestCodeEntry* entry = cache->AddAndLockForWrapping(pc);
48 if (entry) {
49 MachineCode mc;
50 GenTrampolineAdaptor(&mc, pc, AsHostCode(func), arg, name);
51 cache->SetWrappedAndUnlock(pc,
52 entry,
53 is_host_func,
54 // TODO(b/232598137): Maybe use ColdCodePool?
55 {GetDefaultCodePoolInstance()->Add(&mc), mc.install_size()});
56 }
57 }
58
UnwrapHostFunction(GuestAddr pc)59 void* UnwrapHostFunction(GuestAddr pc) {
60 if (TranslationCache::GetInstance()->IsHostFunctionWrapped(pc)) {
61 // Wrapped entry.
62 return ToHostAddr<void>(pc);
63 }
64 return nullptr;
65 }
66
67 } // namespace berberis
68