1 //===-- xray_interface_internal.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 // This file is a part of XRay, a dynamic runtime instrumentation system.
10 //
11 // Implementation of the API functions. See also include/xray/xray_interface.h.
12 //
13 //===----------------------------------------------------------------------===//
14 #ifndef XRAY_INTERFACE_INTERNAL_H
15 #define XRAY_INTERFACE_INTERNAL_H
16
17 #include "sanitizer_common/sanitizer_platform.h"
18 #include "xray/xray_interface.h"
19 #include <cstddef>
20 #include <cstdint>
21 #include <utility>
22
23 extern "C" {
24 // The following functions have to be defined in assembler, on a per-platform
25 // basis. See xray_trampoline_*.S files for implementations.
26 extern void __xray_FunctionEntry();
27 extern void __xray_FunctionExit();
28 extern void __xray_FunctionTailExit();
29 extern void __xray_ArgLoggerEntry();
30 extern void __xray_CustomEvent();
31 extern void __xray_TypedEvent();
32 #if defined(__s390x__)
33 extern void __xray_FunctionEntryVec();
34 extern void __xray_FunctionExitVec();
35 #endif
36 }
37
38 extern "C" {
39
40 struct XRaySledEntry {
41 #if SANITIZER_WORDSIZE == 64
42 uint64_t Address;
43 uint64_t Function;
44 unsigned char Kind;
45 unsigned char AlwaysInstrument;
46 unsigned char Version;
47 unsigned char Padding[13]; // Need 32 bytes
functionXRaySledEntry48 uint64_t function() const {
49 // The target address is relative to the location of the Function variable.
50 return reinterpret_cast<uint64_t>(&Function) + Function;
51 }
addressXRaySledEntry52 uint64_t address() const {
53 // The target address is relative to the location of the Address variable.
54 return reinterpret_cast<uint64_t>(&Address) + Address;
55 }
56 #elif SANITIZER_WORDSIZE == 32
57 uint32_t Address;
58 uint32_t Function;
59 unsigned char Kind;
60 unsigned char AlwaysInstrument;
61 unsigned char Version;
62 unsigned char Padding[5]; // Need 16 bytes
63 uint32_t function() const {
64 // The target address is relative to the location of the Function variable.
65 return reinterpret_cast<uint32_t>(&Function) + Function;
66 }
67 uint32_t address() const {
68 // The target address is relative to the location of the Address variable.
69 return reinterpret_cast<uint32_t>(&Address) + Address;
70 }
71 #else
72 #error "Unsupported word size."
73 #endif
74 };
75
76 struct XRayFunctionSledIndex {
77 const XRaySledEntry *Begin;
78 size_t Size;
79 // For an entry in the xray_fn_idx section, the address is relative to the
80 // location of the Begin variable.
fromPCRelativeXRayFunctionSledIndex81 const XRaySledEntry *fromPCRelative() const {
82 return reinterpret_cast<const XRaySledEntry *>(uintptr_t(&Begin) +
83 uintptr_t(Begin));
84 }
85 };
86
87 struct XRayTrampolines {
88 void (*EntryTrampoline)();
89 void (*ExitTrampoline)();
90 void (*TailExitTrampoline)();
91 void (*LogArgsTrampoline)();
92
XRayTrampolinesXRayTrampolines93 XRayTrampolines() {
94 // These resolve to the definitions in the respective executable or DSO.
95 EntryTrampoline = __xray_FunctionEntry;
96 ExitTrampoline = __xray_FunctionExit;
97 TailExitTrampoline = __xray_FunctionTailExit;
98 LogArgsTrampoline = __xray_ArgLoggerEntry;
99 }
100 };
101
102 extern int32_t __xray_register_dso(const XRaySledEntry *SledsBegin,
103 const XRaySledEntry *SledsEnd,
104 const XRayFunctionSledIndex *FnIndexBegin,
105 const XRayFunctionSledIndex *FnIndexEnd,
106 XRayTrampolines Trampolines);
107
108 extern bool __xray_deregister_dso(int32_t ObjId);
109 }
110
111 namespace __xray {
112
113 constexpr uint32_t XRayNFnBits = 24;
114 constexpr uint32_t XRayNObjBits = 8;
115
116 constexpr uint32_t XRayFnBitMask = 0x00FFFFFF;
117 constexpr uint32_t XRayObjBitMask = 0xFF000000;
118
119 constexpr size_t XRayMaxFunctions = 1 << XRayNFnBits;
120 constexpr size_t XRayMaxObjects = 1 << XRayNObjBits;
121
MakePackedId(int32_t FnId,int32_t ObjId)122 inline int32_t MakePackedId(int32_t FnId, int32_t ObjId) {
123 return ((ObjId << XRayNFnBits) & XRayObjBitMask) | (FnId & XRayFnBitMask);
124 }
125
UnpackId(int32_t PackedId)126 inline std::pair<int32_t, int32_t> UnpackId(int32_t PackedId) {
127 uint32_t ObjId = (PackedId & XRayObjBitMask) >> XRayNFnBits;
128 uint32_t FnId = PackedId & XRayFnBitMask;
129 return {ObjId, FnId};
130 }
131
132 struct XRaySledMap {
133 const XRaySledEntry *Sleds;
134 size_t Entries;
135 const XRayFunctionSledIndex *SledsIndex;
136 size_t Functions;
137 XRayTrampolines Trampolines;
138 bool FromDSO;
139 bool Loaded;
140 };
141
142 bool patchFunctionEntry(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled,
143 const XRayTrampolines &Trampolines, bool LogArgs);
144 bool patchFunctionExit(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled,
145 const XRayTrampolines &Trampolines);
146 bool patchFunctionTailExit(bool Enable, uint32_t FuncId,
147 const XRaySledEntry &Sled,
148 const XRayTrampolines &Trampolines);
149 bool patchCustomEvent(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled);
150 bool patchTypedEvent(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled);
151
152 } // namespace __xray
153
154 #endif
155