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abseil-cpp
Commit 823b8378 by Evan Brown Committed by Copybara-Service
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In sanitizer mode, detect when end iterators from different swisstables are compared. 

We change AssertSameContainer to be after AssertIsValidForComparison calls so that we can have more specific failure messages.

PiperOrigin-RevId: 508472485
Change-Id: Iff2f7512086948a4aca7fd403596e8d4fde53b2a
parent dcaed1a0
Showing with 77 additions and 22 deletions
absl/container/internal/raw_hash_set.h
......@@ -853,6 +853,9 @@ class HashSetIteratorGenerationInfoEnabled {
void set_generation_ptr(const GenerationType* ptr) { generation_ptr_ = ptr; }
private:
// TODO(b/254649633): use a different static generation for default
// constructed iterators so that we can detect when default constructed
// iterators are compared to iterators from empty tables.
const GenerationType* generation_ptr_ = EmptyGeneration();
GenerationType generation_ = *generation_ptr_;
};
......@@ -1087,12 +1090,33 @@ inline bool AreItersFromSameContainer(const ctrl_t* ctrl_a,
// Asserts that two iterators come from the same container.
// Note: we take slots by reference so that it's not UB if they're uninitialized
// as long as we don't read them (when ctrl is null).
// TODO(b/254649633): when generations are enabled, we can detect more cases of
// different containers by comparing the pointers to the generations - this
// can cover cases of end iterators that we would otherwise miss.
inline void AssertSameContainer(const ctrl_t* ctrl_a, const ctrl_t* ctrl_b,
const void* const& slot_a,
const void* const& slot_b) {
const void* const& slot_b,
const GenerationType* generation_ptr_a,
const GenerationType* generation_ptr_b) {
if (SwisstableGenerationsEnabled() && generation_ptr_a != generation_ptr_b) {
// TODO(b/254649633): use a different static generation for default
// constructed iterators so that we can split the empty/default cases.
const bool a_is_empty_or_default = generation_ptr_a == EmptyGeneration();
const bool b_is_empty_or_default = generation_ptr_b == EmptyGeneration();
if (a_is_empty_or_default != b_is_empty_or_default) {
ABSL_INTERNAL_LOG(FATAL,
"Invalid iterator comparison. Comparing iterator from "
"a non-empty hashtable with an iterator from an empty "
"hashtable or a default-constructed iterator.");
}
const bool a_is_end = ctrl_a == nullptr;
const bool b_is_end = ctrl_b == nullptr;
if (a_is_end || b_is_end) {
ABSL_INTERNAL_LOG(FATAL,
"Invalid iterator comparison. Comparing iterator with "
"an end() iterator from a different hashtable.");
}
ABSL_INTERNAL_LOG(FATAL,
"Invalid iterator comparison. Comparing non-end() "
"iterators from different hashtables.");
}
ABSL_HARDENING_ASSERT(
AreItersFromSameContainer(ctrl_a, ctrl_b, slot_a, slot_b) &&
"Invalid iterator comparison. The iterators may be from different "
......@@ -1463,9 +1487,10 @@ class raw_hash_set {
}
friend bool operator==(const iterator& a, const iterator& b) {
AssertSameContainer(a.ctrl_, b.ctrl_, a.slot_, b.slot_);
AssertIsValidForComparison(a.ctrl_, a.generation(), a.generation_ptr());
AssertIsValidForComparison(b.ctrl_, b.generation(), b.generation_ptr());
AssertSameContainer(a.ctrl_, b.ctrl_, a.slot_, b.slot_,
a.generation_ptr(), b.generation_ptr());
return a.ctrl_ == b.ctrl_;
}
friend bool operator!=(const iterator& a, const iterator& b) {
......@@ -1499,6 +1524,8 @@ class raw_hash_set {
if (ABSL_PREDICT_FALSE(*ctrl_ == ctrl_t::kSentinel)) ctrl_ = nullptr;
}
// TODO(b/254649633): use non-null control for default-constructed iterators
// so that we can distinguish between them and end iterators in debug mode.
ctrl_t* ctrl_ = nullptr;
// To avoid uninitialized member warnings, put slot_ in an anonymous union.
// The member is not initialized on singleton and end iterators.
......
absl/container/internal/raw_hash_set_test.cc
......@@ -2078,6 +2078,19 @@ TEST(TableDeathTest, InvalidIteratorAsserts) {
"erased or .*the table might have rehashed.");
}
// Invalid iterator use can trigger heap-use-after-free in asan,
// use-of-uninitialized-value in msan, or invalidated iterator assertions.
constexpr const char* kInvalidIteratorDeathMessage =
"heap-use-after-free|use-of-uninitialized-value|invalidated "
"iterator|Invalid iterator";
// MSVC doesn't support | in regex.
#if defined(_MSC_VER)
constexpr bool kMsvc = true;
#else
constexpr bool kMsvc = false;
#endif
TEST(TableDeathTest, IteratorInvalidAssertsEqualityOperator) {
if (!IsAssertEnabled()) GTEST_SKIP() << "Assertions not enabled.";
......@@ -2105,15 +2118,18 @@ TEST(TableDeathTest, IteratorInvalidAssertsEqualityOperator) {
iter1 = t1.begin();
iter2 = t2.begin();
const char* const kContainerDiffDeathMessage =
"Invalid iterator comparison. The iterators may be from different "
".*containers or the container might have rehashed.";
SwisstableGenerationsEnabled()
? "Invalid iterator comparison.*non-end"
: "Invalid iterator comparison. The iterators may be from different "
".*containers or the container might have rehashed.";
EXPECT_DEATH_IF_SUPPORTED(void(iter1 == iter2), kContainerDiffDeathMessage);
EXPECT_DEATH_IF_SUPPORTED(void(iter2 == iter1), kContainerDiffDeathMessage);
for (int i = 0; i < 10; ++i) t1.insert(i);
// There should have been a rehash in t1.
if (kMsvc) return; // MSVC doesn't support | in regex.
EXPECT_DEATH_IF_SUPPORTED(void(iter1 == t1.begin()),
kContainerDiffDeathMessage);
kInvalidIteratorDeathMessage);
}
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
......@@ -2258,21 +2274,9 @@ TEST(Table, AlignOne) {
}
}
// Invalid iterator use can trigger heap-use-after-free in asan,
// use-of-uninitialized-value in msan, or invalidated iterator assertions.
constexpr const char* kInvalidIteratorDeathMessage =
"heap-use-after-free|use-of-uninitialized-value|invalidated "
"iterator|Invalid iterator";
#if defined(__clang__) && defined(_MSC_VER)
constexpr bool kLexan = true;
#else
constexpr bool kLexan = false;
#endif
TEST(Iterator, InvalidUseCrashesWithSanitizers) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
if (kLexan) GTEST_SKIP() << "Lexan doesn't support | in regexp.";
if (kMsvc) GTEST_SKIP() << "MSVC doesn't support | in regexp.";
IntTable t;
// Start with 1 element so that `it` is never an end iterator.
......@@ -2288,7 +2292,7 @@ TEST(Iterator, InvalidUseCrashesWithSanitizers) {
TEST(Iterator, InvalidUseWithReserveCrashesWithSanitizers) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
if (kLexan) GTEST_SKIP() << "Lexan doesn't support | in regexp.";
if (kMsvc) GTEST_SKIP() << "MSVC doesn't support | in regexp.";
IntTable t;
t.reserve(10);
......@@ -2349,6 +2353,30 @@ TEST(Table, InvalidReferenceUseCrashesWithSanitizers) {
}
}
TEST(Iterator, InvalidComparisonDifferentTables) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
IntTable t1, t2;
IntTable::iterator default_constructed_iter;
// TODO(b/254649633): Currently, we can't detect when end iterators from
// different empty tables are compared. If we allocate generations separately
// from control bytes, then we could do so.
// EXPECT_DEATH_IF_SUPPORTED(void(t1.end() == t2.end()),
// "Invalid iterator comparison.*empty hashtable");
// EXPECT_DEATH_IF_SUPPORTED(void(t1.end() == default_constructed_iter),
// "Invalid iterator comparison.*default-const...");
t1.insert(0);
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == t2.end()),
"Invalid iterator comparison.*empty hashtable");
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == default_constructed_iter),
"Invalid iterator comparison.*default-constructed");
t2.insert(0);
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == t2.end()),
"Invalid iterator comparison.*end.. iterator");
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == t2.begin()),
"Invalid iterator comparison.*non-end");
}
} // namespace
} // namespace container_internal
ABSL_NAMESPACE_END
......
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