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1 /*
2  * Copyright (C) 2018 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 #ifndef SRC_PROFILING_COMMON_UNWIND_SUPPORT_H_
18 #define SRC_PROFILING_COMMON_UNWIND_SUPPORT_H_
19 
20 // defines PERFETTO_BUILDFLAG
21 #include "perfetto/base/build_config.h"
22 
23 #include <memory>
24 #include <string>
25 
26 #include <unwindstack/Maps.h>
27 #include <unwindstack/Unwinder.h>
28 #if PERFETTO_BUILDFLAG(PERFETTO_ANDROID_BUILD)
29 #include <unwindstack/DexFiles.h>
30 #include <unwindstack/JitDebug.h>
31 #endif
32 
33 #include "perfetto/base/logging.h"
34 #include "perfetto/base/time.h"
35 #include "perfetto/ext/base/scoped_file.h"
36 
37 namespace perfetto {
38 namespace profiling {
39 
40 // libunwindstack's FrameData annotated with the build_id.
41 struct FrameData {
FrameDataFrameData42   FrameData(unwindstack::FrameData f, std::string id)
43       : frame(std::move(f)), build_id(std::move(id)) {}
44 
45   unwindstack::FrameData frame;
46   std::string build_id;
47 };
48 
49 // Read /proc/[pid]/maps from an open file descriptor.
50 // TODO(fmayer): Figure out deduplication to other maps.
51 class FDMaps : public unwindstack::Maps {
52  public:
53   FDMaps(base::ScopedFile fd);
54 
55   FDMaps(const FDMaps&) = delete;
56   FDMaps& operator=(const FDMaps&) = delete;
57 
FDMaps(FDMaps && m)58   FDMaps(FDMaps&& m) : Maps(std::move(m)) { fd_ = std::move(m.fd_); }
59 
60   FDMaps& operator=(FDMaps&& m) {
61     if (&m != this)
62       fd_ = std::move(m.fd_);
63     Maps::operator=(std::move(m));
64     return *this;
65   }
66 
67   virtual ~FDMaps() override = default;
68 
69   bool Parse() override;
70   void Reset();
71 
72  private:
73   base::ScopedFile fd_;
74 };
75 
76 class FDMemory : public unwindstack::Memory {
77  public:
78   FDMemory(base::ScopedFile mem_fd);
79   size_t Read(uint64_t addr, void* dst, size_t size) override;
80 
81  private:
82   base::ScopedFile mem_fd_;
83 };
84 
85 // Overlays size bytes pointed to by stack for addresses in [sp, sp + size).
86 // Addresses outside of that range are read from mem_fd, which should be an fd
87 // that opened /proc/[pid]/mem.
88 class StackOverlayMemory : public unwindstack::Memory {
89  public:
90   StackOverlayMemory(std::shared_ptr<unwindstack::Memory> mem,
91                      uint64_t sp,
92                      const uint8_t* stack,
93                      size_t size);
94   size_t Read(uint64_t addr, void* dst, size_t size) override;
95 
96  private:
97   std::shared_ptr<unwindstack::Memory> mem_;
98   const uint64_t sp_;
99   const uint64_t stack_end_;
100   const uint8_t* const stack_;
101 };
102 
103 struct UnwindingMetadata {
104   UnwindingMetadata(base::ScopedFile maps_fd, base::ScopedFile mem_fd);
105 
106   // move-only
107   UnwindingMetadata(const UnwindingMetadata&) = delete;
108   UnwindingMetadata& operator=(const UnwindingMetadata&) = delete;
109 
110   UnwindingMetadata(UnwindingMetadata&&) = default;
111   UnwindingMetadata& operator=(UnwindingMetadata&&) = default;
112 
113   void ReparseMaps();
114 
115   FrameData AnnotateFrame(unwindstack::FrameData frame);
116 
117   FDMaps fd_maps;
118   // The API of libunwindstack expects shared_ptr for Memory.
119   std::shared_ptr<unwindstack::Memory> fd_mem;
120   uint64_t reparses = 0;
121   base::TimeMillis last_maps_reparse_time{0};
122 #if PERFETTO_BUILDFLAG(PERFETTO_ANDROID_BUILD)
123   std::unique_ptr<unwindstack::JitDebug> jit_debug;
124   std::unique_ptr<unwindstack::DexFiles> dex_files;
125 #endif
126 };
127 
128 std::string StringifyLibUnwindstackError(unwindstack::ErrorCode);
129 
130 }  // namespace profiling
131 }  // namespace perfetto
132 
133 #endif  // SRC_PROFILING_COMMON_UNWIND_SUPPORT_H_
134