1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
// Copyright (c) 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "source/fuzz/fuzzer_pass_add_loads.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/transformation_load.h"
namespace spvtools {
namespace fuzz {
FuzzerPassAddLoads::FuzzerPassAddLoads(
opt::IRContext* ir_context, TransformationContext* transformation_context,
FuzzerContext* fuzzer_context,
protobufs::TransformationSequence* transformations,
bool ignore_inapplicable_transformations)
: FuzzerPass(ir_context, transformation_context, fuzzer_context,
transformations, ignore_inapplicable_transformations) {}
void FuzzerPassAddLoads::Apply() {
ForEachInstructionWithInstructionDescriptor(
[this](opt::Function* function, opt::BasicBlock* block,
opt::BasicBlock::iterator inst_it,
const protobufs::InstructionDescriptor& instruction_descriptor)
-> void {
assert(
inst_it->opcode() ==
spv::Op(instruction_descriptor.target_instruction_opcode()) &&
"The opcode of the instruction we might insert before must be "
"the same as the opcode in the descriptor for the instruction");
// Randomly decide whether to try inserting a load here.
if (!GetFuzzerContext()->ChoosePercentage(
GetFuzzerContext()->GetChanceOfAddingLoad())) {
return;
}
// Check whether it is legitimate to insert a load or atomic load before
// this instruction.
if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(spv::Op::OpLoad,
inst_it)) {
return;
}
if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(spv::Op::OpAtomicLoad,
inst_it)) {
return;
}
std::vector<opt::Instruction*> relevant_instructions =
FindAvailableInstructions(
function, block, inst_it,
[](opt::IRContext* context,
opt::Instruction* instruction) -> bool {
if (!instruction->result_id() || !instruction->type_id()) {
return false;
}
switch (instruction->opcode()) {
case spv::Op::OpConstantNull:
case spv::Op::OpUndef:
// Do not allow loading from a null or undefined pointer;
// this might be OK if the block is dead, but for now we
// conservatively avoid it.
return false;
default:
break;
}
return context->get_def_use_mgr()
->GetDef(instruction->type_id())
->opcode() == spv::Op::OpTypePointer;
});
// At this point, |relevant_instructions| contains all the pointers
// we might think of loading from.
if (relevant_instructions.empty()) {
return;
}
auto chosen_instruction =
relevant_instructions[GetFuzzerContext()->RandomIndex(
relevant_instructions)];
bool is_atomic_load = false;
uint32_t memory_scope_id = 0;
uint32_t memory_semantics_id = 0;
auto storage_class = static_cast<spv::StorageClass>(
GetIRContext()
->get_def_use_mgr()
->GetDef(chosen_instruction->type_id())
->GetSingleWordInOperand(0));
switch (storage_class) {
case spv::StorageClass::StorageBuffer:
case spv::StorageClass::PhysicalStorageBuffer:
case spv::StorageClass::Workgroup:
case spv::StorageClass::CrossWorkgroup:
case spv::StorageClass::AtomicCounter:
case spv::StorageClass::Image:
if (GetFuzzerContext()->ChoosePercentage(
GetFuzzerContext()->GetChanceOfAddingAtomicLoad())) {
is_atomic_load = true;
memory_scope_id = FindOrCreateConstant(
{uint32_t(spv::Scope::Invocation)},
FindOrCreateIntegerType(32, GetFuzzerContext()->ChooseEven()),
false);
memory_semantics_id = FindOrCreateConstant(
{static_cast<uint32_t>(
fuzzerutil::GetMemorySemanticsForStorageClass(
storage_class))},
FindOrCreateIntegerType(32, GetFuzzerContext()->ChooseEven()),
false);
}
break;
default:
break;
}
// Create and apply the transformation.
ApplyTransformation(TransformationLoad(
GetFuzzerContext()->GetFreshId(), chosen_instruction->result_id(),
is_atomic_load, memory_scope_id, memory_semantics_id,
instruction_descriptor));
});
}
} // namespace fuzz
} // namespace spvtools
|
