xref: /aosp_15_r20/system/unwinding/libunwindstack/tools/unwind.cpp (revision eb293b8f56ee8303637c5595cfcdeef8039e85c6)
1 /*
2  * Copyright (C) 2016 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 <elf.h>
18 #include <errno.h>
19 #include <inttypes.h>
20 #include <signal.h>
21 #include <stdint.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/ptrace.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 
29 #include <unwindstack/AndroidUnwinder.h>
30 #include <unwindstack/Regs.h>
31 
Attach(pid_t pid)32 static bool Attach(pid_t pid) {
33   if (ptrace(PTRACE_SEIZE, pid, 0, 0) == -1) {
34     return false;
35   }
36 
37   if (ptrace(PTRACE_INTERRUPT, pid, 0, 0) == -1) {
38     ptrace(PTRACE_DETACH, pid, 0, 0);
39     return false;
40   }
41 
42   // Allow at least 1 second to attach properly.
43   for (size_t i = 0; i < 1000; i++) {
44     siginfo_t si;
45     if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si) == 0) {
46       return true;
47     }
48     usleep(1000);
49   }
50   printf("%d: Failed to stop.\n", pid);
51   return false;
52 }
53 
DoUnwind(pid_t pid)54 void DoUnwind(pid_t pid) {
55   unwindstack::Regs* regs = unwindstack::Regs::RemoteGet(pid);
56   if (regs == nullptr) {
57     printf("Unable to get remote reg data\n");
58     return;
59   }
60 
61   printf("ABI: ");
62   switch (regs->Arch()) {
63     case unwindstack::ARCH_ARM:
64       printf("arm");
65       break;
66     case unwindstack::ARCH_X86:
67       printf("x86");
68       break;
69     case unwindstack::ARCH_ARM64:
70       printf("arm64");
71       break;
72     case unwindstack::ARCH_X86_64:
73       printf("x86_64");
74       break;
75     case unwindstack::ARCH_RISCV64:
76       printf("riscv64");
77       break;
78     default:
79       printf("unknown\n");
80       return;
81   }
82   printf("\n");
83 
84   unwindstack::AndroidRemoteUnwinder unwinder(pid);
85   unwindstack::AndroidUnwinderData data;
86   if (!unwinder.Unwind(regs, data)) {
87     printf("Unable to unwind pid %d: %s\n", pid, data.GetErrorString().c_str());
88     return;
89   }
90   data.DemangleFunctionNames();
91 
92   // Print the frames.
93   for (const auto& frame : data.frames) {
94     printf("%s\n", unwinder.FormatFrame(frame).c_str());
95   }
96 }
97 
main(int argc,char ** argv)98 int main(int argc, char** argv) {
99   if (argc != 2) {
100     printf("Usage: unwind <PID>\n");
101     return 1;
102   }
103 
104   pid_t pid = atoi(argv[1]);
105   if (!Attach(pid)) {
106     printf("Failed to attach to pid %d: %s\n", pid, strerror(errno));
107     return 1;
108   }
109 
110   DoUnwind(pid);
111 
112   ptrace(PTRACE_DETACH, pid, 0, 0);
113 
114   return 0;
115 }
116