1 //===-- xray_powerpc64.cpp --------------------------------------*- 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 powerpc64 and powerpc64le routines.
12 //
13 //===----------------------------------------------------------------------===//
14 #include "sanitizer_common/sanitizer_common.h"
15 #include "xray_defs.h"
16 #include "xray_interface_internal.h"
17 #include "xray_utils.h"
18 #include <atomic>
19 #include <cassert>
20 #include <cstring>
21 
22 #ifndef __LITTLE_ENDIAN__
23 #error powerpc64 big endian is not supported for now.
24 #endif
25 
26 namespace {
27 
28 constexpr unsigned long long JumpOverInstNum = 7;
29 
30 void clearCache(void *Addr, size_t Len) {
31   const size_t LineSize = 32;
32 
33   const intptr_t Mask = ~(LineSize - 1);
34   const intptr_t StartLine = ((intptr_t)Addr) & Mask;
35   const intptr_t EndLine = ((intptr_t)Addr + Len + LineSize - 1) & Mask;
36 
37   for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
38     asm volatile("dcbf 0, %0" : : "r"(Line));
39   asm volatile("sync");
40 
41   for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
42     asm volatile("icbi 0, %0" : : "r"(Line));
43   asm volatile("isync");
44 }
45 
46 } // namespace
47 
48 extern "C" void __clear_cache(void *start, void *end);
49 
50 namespace __xray {
51 
52 bool patchFunctionEntry(const bool Enable, uint32_t FuncId,
53                         const XRaySledEntry &Sled,
54                         void (*Trampoline)()) XRAY_NEVER_INSTRUMENT {
55   const uint64_t Address = Sled.address();
56   if (Enable) {
57     // lis 0, FuncId[16..32]
58     // li 0, FuncId[0..15]
59     *reinterpret_cast<uint64_t *>(Address) =
60         (0x3c000000ull + (FuncId >> 16)) +
61         ((0x60000000ull + (FuncId & 0xffff)) << 32);
62   } else {
63     // b +JumpOverInstNum instructions.
64     *reinterpret_cast<uint32_t *>(Address) =
65         0x48000000ull + (JumpOverInstNum << 2);
66   }
67   clearCache(reinterpret_cast<void *>(Address), 8);
68   return true;
69 }
70 
71 bool patchFunctionExit(const bool Enable, uint32_t FuncId,
72                        const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {
73   const uint64_t Address = Sled.address();
74   if (Enable) {
75     // lis 0, FuncId[16..32]
76     // li 0, FuncId[0..15]
77     *reinterpret_cast<uint64_t *>(Address) =
78         (0x3c000000ull + (FuncId >> 16)) +
79         ((0x60000000ull + (FuncId & 0xffff)) << 32);
80   } else {
81     // Copy the blr/b instruction after JumpOverInstNum instructions.
82     *reinterpret_cast<uint32_t *>(Address) =
83         *(reinterpret_cast<uint32_t *>(Address) + JumpOverInstNum);
84   }
85   clearCache(reinterpret_cast<void *>(Address), 8);
86   return true;
87 }
88 
89 bool patchFunctionTailExit(const bool Enable, const uint32_t FuncId,
90                            const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {
91   return patchFunctionExit(Enable, FuncId, Sled);
92 }
93 
94 // FIXME: Maybe implement this better?
95 bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
96 
97 bool patchCustomEvent(const bool Enable, const uint32_t FuncId,
98                       const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {
99   // FIXME: Implement in powerpc64?
100   return false;
101 }
102 
103 bool patchTypedEvent(const bool Enable, const uint32_t FuncId,
104                      const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {
105   // FIXME: Implement in powerpc64?
106   return false;
107 }
108 
109 } // namespace __xray
110 
111 extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT {
112   // FIXME: this will have to be implemented in the trampoline assembly file
113 }
114