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
23extern "C" {
24// The following functions have to be defined in assembler, on a per-platform
25// basis. See xray_trampoline_*.S files for implementations.
26extern void __xray_FunctionEntry();
27extern void __xray_FunctionExit();
28extern void __xray_FunctionTailExit();
29extern void __xray_ArgLoggerEntry();
30extern void __xray_CustomEvent();
31extern void __xray_TypedEvent();
32#if defined(__s390x__)
33extern void __xray_FunctionEntryVec();
34extern void __xray_FunctionExitVec();
35#endif
36}
37
38extern "C" {
39
40struct 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
48 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 }
52 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
76struct 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.
81 const XRaySledEntry *fromPCRelative() const {
82 return reinterpret_cast<const XRaySledEntry *>(uintptr_t(&Begin) +
83 uintptr_t(Begin));
84 }
85};
86
87struct XRayTrampolines {
88 void (*EntryTrampoline)();
89 void (*ExitTrampoline)();
90 void (*TailExitTrampoline)();
91 void (*LogArgsTrampoline)();
92
93 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
102extern int32_t __xray_register_dso(const XRaySledEntry *SledsBegin,
103 const XRaySledEntry *SledsEnd,
104 const XRayFunctionSledIndex *FnIndexBegin,
105 const XRayFunctionSledIndex *FnIndexEnd,
106 XRayTrampolines Trampolines);
107
108extern bool __xray_deregister_dso(int32_t ObjId);
109}
110
111namespace __xray {
112
113constexpr uint32_t XRayNFnBits = 24;
114constexpr uint32_t XRayNObjBits = 8;
115
116constexpr uint32_t XRayFnBitMask = 0x00FFFFFF;
117constexpr uint32_t XRayObjBitMask = 0xFF000000;
118
119constexpr size_t XRayMaxFunctions = 1 << XRayNFnBits;
120constexpr size_t XRayMaxObjects = 1 << XRayNObjBits;
121
122inline int32_t MakePackedId(int32_t FnId, int32_t ObjId) {
123 return ((ObjId << XRayNFnBits) & XRayObjBitMask) | (FnId & XRayFnBitMask);
124}
125
126inline 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
132struct 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
142bool patchFunctionEntry(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled,
143 const XRayTrampolines &Trampolines, bool LogArgs);
144bool patchFunctionExit(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled,
145 const XRayTrampolines &Trampolines);
146bool patchFunctionTailExit(bool Enable, uint32_t FuncId,
147 const XRaySledEntry &Sled,
148 const XRayTrampolines &Trampolines);
149bool patchCustomEvent(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled);
150bool patchTypedEvent(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled);
151
152} // namespace __xray
153
154#endif
155