LLDB  mainline
SingleStepCheck.h
Go to the documentation of this file.
1 //===-- SingleStepCheck.h ------------------------------------- -*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef liblldb_SingleStepCheck_H_
10 #define liblldb_SingleStepCheck_H_
11 
12 #include <memory>
13 #include <sched.h>
14 #include <sys/types.h>
15 
16 namespace lldb_private {
17 namespace process_linux {
18 
19 // arm64 linux had a bug which prevented single-stepping and watchpoints from
20 // working on non-boot cpus, due to them being incorrectly initialized after
21 // coming out of suspend. This issue is particularly affecting android M, which
22 // uses suspend ("doze mode") quite aggressively. This code detects that
23 // situation and makes single-stepping work by doing all the step operations on
24 // the boot cpu.
25 //
26 // The underlying issue has been fixed in android N and linux 4.4. This code can
27 // be removed once these systems become obsolete.
28 
29 #if defined(__arm64__) || defined(__aarch64__)
30 class SingleStepWorkaround {
31  ::pid_t m_tid;
32  cpu_set_t m_original_set;
33 
34  SingleStepWorkaround(const SingleStepWorkaround &) = delete;
35  void operator=(const SingleStepWorkaround &) = delete;
36 
37 public:
38  SingleStepWorkaround(::pid_t tid, cpu_set_t original_set)
39  : m_tid(tid), m_original_set(original_set) {}
40  ~SingleStepWorkaround();
41 
42  static std::unique_ptr<SingleStepWorkaround> Get(::pid_t tid);
43 };
44 #else
46 public:
47  static std::unique_ptr<SingleStepWorkaround> Get(::pid_t tid) {
48  return nullptr;
49  }
50 };
51 #endif
52 
53 } // end namespace process_linux
54 } // end namespace lldb_private
55 
56 #endif // #ifndef liblldb_SingleStepCheck_H_
lldb_private::process_linux::SingleStepWorkaround::Get
static std::unique_ptr< SingleStepWorkaround > Get(::pid_t tid)
Definition: SingleStepCheck.h:47
lldb::pid_t
uint64_t pid_t
Definition: lldb-types.h:85
lldb_private
A class that represents a running process on the host machine.
Definition: SBCommandInterpreterRunOptions.h:16
lldb_private::process_linux::SingleStepWorkaround
Definition: SingleStepCheck.h:45