1 //===-- asan_mapping_sparc64.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 AddressSanitizer, an address sanity checker.
10 //
11 // SPARC64-specific definitions for ASan memory mapping.
12 //===----------------------------------------------------------------------===//
13 #ifndef ASAN_MAPPING_SPARC64_H
14 #define ASAN_MAPPING_SPARC64_H
15 
16 // This is tailored to the 52-bit VM layout on SPARC-T4 and later.
17 // The VM space is split into two 51-bit halves at both ends: the low part
18 // has all the bits above the 51st cleared, while the high part has them set.
19 //   0xfff8000000000000 - 0xffffffffffffffff
20 //   0x0000000000000000 - 0x0007ffffffffffff
21 
22 #define VMA_BITS 52
23 #define HIGH_BITS (64 - VMA_BITS)
24 
25 // The idea is to chop the high bits before doing the scaling, so the two
26 // parts become contiguous again and the usual scheme can be applied.
27 
28 #define MEM_TO_SHADOW(mem)                                       \
29   ((((mem) << HIGH_BITS) >> (HIGH_BITS + (ASAN_SHADOW_SCALE))) + \
30    (ASAN_SHADOW_OFFSET))
31 #define SHADOW_TO_MEM(ptr) (__asan::ShadowToMemSparc64(ptr))
32 
33 #define kLowMemBeg 0
34 #define kLowMemEnd (ASAN_SHADOW_OFFSET - 1)
35 
36 #define kLowShadowBeg ASAN_SHADOW_OFFSET
37 #define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd)
38 
39 // But of course there is the huge hole between the high shadow memory,
40 // which is in the low part, and the beginning of the high part.
41 
42 #define kHighMemBeg (-(1ULL << (VMA_BITS - 1)))
43 
44 #define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg)
45 #define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd)
46 
47 #define kMidShadowBeg 0
48 #define kMidShadowEnd 0
49 
50 // With the zero shadow base we can not actually map pages starting from 0.
51 // This constant is somewhat arbitrary.
52 #define kZeroBaseShadowStart 0
53 #define kZeroBaseMaxShadowStart (1 << 18)
54 
55 #define kShadowGapBeg (kLowShadowEnd + 1)
56 #define kShadowGapEnd (kHighShadowBeg - 1)
57 
58 #define kShadowGap2Beg 0
59 #define kShadowGap2End 0
60 
61 #define kShadowGap3Beg 0
62 #define kShadowGap3End 0
63 
64 namespace __asan {
65 
AddrIsInLowMem(uptr a)66 static inline bool AddrIsInLowMem(uptr a) {
67   PROFILE_ASAN_MAPPING();
68   return a <= kLowMemEnd;
69 }
70 
AddrIsInLowShadow(uptr a)71 static inline bool AddrIsInLowShadow(uptr a) {
72   PROFILE_ASAN_MAPPING();
73   return a >= kLowShadowBeg && a <= kLowShadowEnd;
74 }
75 
AddrIsInMidMem(uptr a)76 static inline bool AddrIsInMidMem(uptr a) {
77   PROFILE_ASAN_MAPPING();
78   return false;
79 }
80 
AddrIsInMidShadow(uptr a)81 static inline bool AddrIsInMidShadow(uptr a) {
82   PROFILE_ASAN_MAPPING();
83   return false;
84 }
85 
AddrIsInHighMem(uptr a)86 static inline bool AddrIsInHighMem(uptr a) {
87   PROFILE_ASAN_MAPPING();
88   return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd;
89 }
90 
AddrIsInHighShadow(uptr a)91 static inline bool AddrIsInHighShadow(uptr a) {
92   PROFILE_ASAN_MAPPING();
93   return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd;
94 }
95 
AddrIsInShadowGap(uptr a)96 static inline bool AddrIsInShadowGap(uptr a) {
97   PROFILE_ASAN_MAPPING();
98   return a >= kShadowGapBeg && a <= kShadowGapEnd;
99 }
100 
ShadowToMemSparc64(uptr p)101 static inline constexpr uptr ShadowToMemSparc64(uptr p) {
102   PROFILE_ASAN_MAPPING();
103   p -= ASAN_SHADOW_OFFSET;
104   p <<= ASAN_SHADOW_SCALE;
105   if (p >= 0x8000000000000) {
106     p |= (~0ULL) << VMA_BITS;
107   }
108   return p;
109 }
110 
111 static_assert(ShadowToMemSparc64(MEM_TO_SHADOW(0x0000000000000000)) ==
112               0x0000000000000000);
113 static_assert(ShadowToMemSparc64(MEM_TO_SHADOW(0xfff8000000000000)) ==
114               0xfff8000000000000);
115 // Gets aligned down.
116 static_assert(ShadowToMemSparc64(MEM_TO_SHADOW(0x0007ffffffffffff)) ==
117               0x0007fffffffffff8);
118 
119 }  // namespace __asan
120 
121 #endif  // ASAN_MAPPING_SPARC64_H
122