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/interpret_helpers.h"
18 
19 #include <signal.h>
20 #include <sys/syscall.h>
21 #include <unistd.h>
22 
23 #include <cstdint>
24 
25 #include "berberis/base/checks.h"
26 #include "berberis/base/logging.h"
27 #include "berberis/guest_state/guest_addr.h"
28 
29 namespace berberis {
30 
31 namespace {
32 
GetRiscv64InsnSize(GuestAddr pc)33 uint8_t GetRiscv64InsnSize(GuestAddr pc) {
34   constexpr uint16_t kInsnLenMask = uint16_t{0b11};
35   if ((*ToHostAddr<const uint16_t>(pc) & kInsnLenMask) != kInsnLenMask) {
36     return 2;
37   }
38   return 4;
39 }
40 
41 }  // namespace
42 
UndefinedInsn(GuestAddr pc)43 void UndefinedInsn(GuestAddr pc) {
44   auto* addr = ToHostAddr<const uint16_t>(pc);
45   uint8_t size = GetRiscv64InsnSize(pc);
46   if (size == 2) {
47     ALOGE("Undefined riscv64 instruction 0x%" PRIx16 " at %p", *addr, addr);
48   } else {
49     CHECK_EQ(size, 4);
50     // Warning: do not cast and dereference the pointer since the address may not be 4-bytes
51     // aligned.
52     uint32_t code;
53     memcpy(&code, addr, sizeof(code));
54     ALOGE("Undefined riscv64 instruction 0x%" PRIx32 " at %p", code, addr);
55   }
56 #ifdef __GLIBC__
57   // Our old 2.17 glibc has a bug resulting in raise() failing after any CLONE_VM.
58   // Work around by calling tgkill directly.
59   pid_t pid = syscall(__NR_getpid);
60   pid_t tid = syscall(__NR_gettid);
61   syscall(SYS_tgkill, pid, tid, SIGILL);
62 #else
63   raise(SIGILL);
64 #endif
65 }
66 
67 }  // namespace berberis
68