clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SafeStackLayout.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -D PIC -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -D_RET_PROTECTOR -ret-protector -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/SafeStackLayout.cpp
1 | |
2 | |
3 | |
4 | |
5 | |
6 | |
7 | |
8 | |
9 | #include "SafeStackLayout.h" |
10 | #include "llvm/IR/Value.h" |
11 | #include "llvm/Support/CommandLine.h" |
12 | #include "llvm/Support/Compiler.h" |
13 | #include "llvm/Support/Debug.h" |
14 | #include "llvm/Support/MathExtras.h" |
15 | #include "llvm/Support/raw_ostream.h" |
16 | #include <algorithm> |
17 | #include <cassert> |
18 | |
19 | using namespace llvm; |
20 | using namespace llvm::safestack; |
21 | |
22 | #define DEBUG_TYPE "safestacklayout" |
23 | |
24 | static cl::opt<bool> ClLayout("safe-stack-layout", |
25 | cl::desc("enable safe stack layout"), cl::Hidden, |
26 | cl::init(true)); |
27 | |
28 | LLVM_DUMP_METHOD void StackLayout::print(raw_ostream &OS) { |
29 | OS << "Stack regions:\n"; |
30 | for (unsigned i = 0; i < Regions.size(); ++i) { |
31 | OS << " " << i << ": [" << Regions[i].Start << ", " << Regions[i].End |
32 | << "), range " << Regions[i].Range << "\n"; |
33 | } |
34 | OS << "Stack objects:\n"; |
35 | for (auto &IT : ObjectOffsets) { |
36 | OS << " at " << IT.getSecond() << ": " << *IT.getFirst() << "\n"; |
37 | } |
38 | } |
39 | |
40 | void StackLayout::addObject(const Value *V, unsigned Size, unsigned Alignment, |
41 | const StackLifetime::LiveRange &Range) { |
42 | StackObjects.push_back({V, Size, Alignment, Range}); |
43 | ObjectAlignments[V] = Alignment; |
44 | MaxAlignment = std::max(MaxAlignment, Alignment); |
45 | } |
46 | |
47 | static unsigned AdjustStackOffset(unsigned Offset, unsigned Size, |
48 | unsigned Alignment) { |
49 | return alignTo(Offset + Size, Alignment) - Size; |
50 | } |
51 | |
52 | void StackLayout::layoutObject(StackObject &Obj) { |
53 | if (!ClLayout) { |
54 | |
55 | |
56 | unsigned LastRegionEnd = Regions.empty() ? 0 : Regions.back().End; |
57 | unsigned Start = AdjustStackOffset(LastRegionEnd, Obj.Size, Obj.Alignment); |
58 | unsigned End = Start + Obj.Size; |
59 | Regions.emplace_back(Start, End, Obj.Range); |
60 | ObjectOffsets[Obj.Handle] = End; |
61 | return; |
62 | } |
63 | |
64 | LLVM_DEBUG(dbgs() << "Layout: size " << Obj.Size << ", align " |
65 | << Obj.Alignment << ", range " << Obj.Range << "\n"); |
66 | assert(Obj.Alignment <= MaxAlignment); |
67 | unsigned Start = AdjustStackOffset(0, Obj.Size, Obj.Alignment); |
68 | unsigned End = Start + Obj.Size; |
69 | LLVM_DEBUG(dbgs() << " First candidate: " << Start << " .. " << End << "\n"); |
70 | for (const StackRegion &R : Regions) { |
71 | LLVM_DEBUG(dbgs() << " Examining region: " << R.Start << " .. " << R.End |
72 | << ", range " << R.Range << "\n"); |
73 | assert(End >= R.Start); |
74 | if (Start >= R.End) { |
75 | LLVM_DEBUG(dbgs() << " Does not intersect, skip.\n"); |
76 | continue; |
77 | } |
78 | if (Obj.Range.overlaps(R.Range)) { |
79 | |
80 | Start = AdjustStackOffset(R.End, Obj.Size, Obj.Alignment); |
81 | End = Start + Obj.Size; |
82 | LLVM_DEBUG(dbgs() << " Overlaps. Next candidate: " << Start << " .. " |
83 | << End << "\n"); |
84 | continue; |
85 | } |
86 | if (End <= R.End) { |
87 | LLVM_DEBUG(dbgs() << " Reusing region(s).\n"); |
88 | break; |
89 | } |
90 | } |
91 | |
92 | unsigned LastRegionEnd = Regions.empty() ? 0 : Regions.back().End; |
93 | if (End > LastRegionEnd) { |
94 | |
95 | if (Start > LastRegionEnd) { |
96 | LLVM_DEBUG(dbgs() << " Creating gap region: " << LastRegionEnd << " .. " |
97 | << Start << "\n"); |
98 | Regions.emplace_back(LastRegionEnd, Start, StackLifetime::LiveRange(0)); |
99 | LastRegionEnd = Start; |
100 | } |
101 | LLVM_DEBUG(dbgs() << " Creating new region: " << LastRegionEnd << " .. " |
102 | << End << ", range " << Obj.Range << "\n"); |
103 | Regions.emplace_back(LastRegionEnd, End, Obj.Range); |
104 | LastRegionEnd = End; |
| Value stored to 'LastRegionEnd' is never read |
105 | } |
106 | |
107 | |
108 | for (unsigned i = 0; i < Regions.size(); ++i) { |
109 | StackRegion &R = Regions[i]; |
110 | if (Start > R.Start && Start < R.End) { |
111 | StackRegion R0 = R; |
112 | R.Start = R0.End = Start; |
113 | Regions.insert(&R, R0); |
114 | continue; |
115 | } |
116 | if (End > R.Start && End < R.End) { |
117 | StackRegion R0 = R; |
118 | R0.End = R.Start = End; |
119 | Regions.insert(&R, R0); |
120 | break; |
121 | } |
122 | } |
123 | |
124 | |
125 | for (StackRegion &R : Regions) { |
126 | if (Start < R.End && End > R.Start) |
127 | R.Range.join(Obj.Range); |
128 | if (End <= R.End) |
129 | break; |
130 | } |
131 | |
132 | ObjectOffsets[Obj.Handle] = End; |
133 | } |
134 | |
135 | void StackLayout::computeLayout() { |
136 | |
137 | |
138 | |
139 | |
140 | |
141 | |
142 | if (StackObjects.size() > 2) |
143 | llvm::stable_sort(drop_begin(StackObjects), |
144 | [](const StackObject &a, const StackObject &b) { |
145 | return a.Size > b.Size; |
146 | }); |
147 | |
148 | for (auto &Obj : StackObjects) |
149 | layoutObject(Obj); |
150 | |
151 | LLVM_DEBUG(print(dbgs())); |
152 | } |