v8/test/unittests/compiler/simplified-lowering-unittest.cc
Jaroslav Sevcik f53dfd934d Replace array index masking with the poisoning approach.
The idea is to mark all the branches and loads participating in array
bounds checks, and let them contribute-to/use the poisoning register.
In the code, the marks for array indexing operations now contain
"Critical" in their name. By default (--untrusted-code-mitigations),
we only instrument the "critical" operations with poisoning.

With that in place, we also remove the array masking approach based
on arithmetic.

Since we do not propagate the poison through function calls,
we introduce a node for poisoning an index that is passed through
function call - the typical example is the bounds-checked index
that is passed to the CharCodeAt builtin.

Most of the code in this CL is threads through the three levels of
protection (safe, critical, unsafe) for loads, branches and flags.

Bug: chromium:798964

Change-Id: Ief68e2329528277b3ba9156115b2a6dcc540d52b
Reviewed-on: https://chromium-review.googlesource.com/995413
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52883}
2018-04-30 13:22:44 +00:00

91 lines
3.0 KiB
C++

// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/compiler/simplified-lowering.h"
#include "src/compiler/compiler-source-position-table.h"
#include "src/compiler/machine-operator.h"
#include "src/compiler/simplified-operator.h"
#include "test/unittests/compiler/graph-unittest.h"
#include "test/unittests/compiler/node-test-utils.h"
namespace v8 {
namespace internal {
namespace compiler {
class SimplifiedLoweringTest : public GraphTest {
public:
explicit SimplifiedLoweringTest(int num_parameters = 1)
: GraphTest(num_parameters),
num_parameters_(num_parameters),
machine_(zone()),
javascript_(zone()),
simplified_(zone()),
jsgraph_(isolate(), graph(), common(), &javascript_, &simplified_,
&machine_) {}
~SimplifiedLoweringTest() override {}
void LowerGraph(Node* node) {
// Make sure we always start with an empty graph.
graph()->SetStart(graph()->NewNode(common()->Start(num_parameters())));
graph()->SetEnd(graph()->NewNode(common()->End(1), graph()->start()));
// Return {node} directly, so that we can match it with
// "IsReturn(expected)".
Node* zero = graph()->NewNode(common()->NumberConstant(0));
Node* ret = graph()->NewNode(common()->Return(), zero, node,
graph()->start(), graph()->start());
NodeProperties::MergeControlToEnd(graph(), common(), ret);
{
// Simplified lowering needs to run w/o the typer decorator so make sure
// the object is not live at the same time.
Typer typer(isolate(), Typer::kNoFlags, graph());
typer.Run();
}
SimplifiedLowering lowering(jsgraph(), zone(), source_positions(),
PoisoningMitigationLevel::kDontPoison);
lowering.LowerAllNodes();
}
int num_parameters() const { return num_parameters_; }
JSGraph* jsgraph() { return &jsgraph_; }
private:
const int num_parameters_;
MachineOperatorBuilder machine_;
JSOperatorBuilder javascript_;
SimplifiedOperatorBuilder simplified_;
JSGraph jsgraph_;
};
const int kSmiValues[] = {Smi::kMinValue,
Smi::kMinValue + 1,
Smi::kMinValue + 2,
3,
2,
1,
0,
-1,
-2,
-3,
Smi::kMaxValue - 2,
Smi::kMaxValue - 1,
Smi::kMaxValue};
TEST_F(SimplifiedLoweringTest, SmiConstantToIntPtrConstant) {
TRACED_FOREACH(int, x, kSmiValues) {
LowerGraph(jsgraph()->Constant(x));
intptr_t smi = bit_cast<intptr_t>(Smi::FromInt(x));
EXPECT_THAT(graph()->end()->InputAt(1),
IsReturn(IsIntPtrConstant(smi), start(), start()));
}
}
} // namespace compiler
} // namespace internal
} // namespace v8