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//===-- recoverable.cpp -----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include <atomic>
#include <mutex>
#include <regex>
#include <string>
#include <thread>
#include <vector>
#include "gwp_asan/common.h"
#include "gwp_asan/crash_handler.h"
#include "gwp_asan/tests/harness.h"
TEST_P(BacktraceGuardedPoolAllocator, MultipleDoubleFreeOnlyOneOutput) {
SCOPED_TRACE("");
void *Ptr = AllocateMemory(GPA);
DeallocateMemory(GPA, Ptr);
// First time should generate a crash report.
DeallocateMemory(GPA, Ptr);
CheckOnlyOneGwpAsanCrash(GetOutputBuffer());
ASSERT_NE(std::string::npos, GetOutputBuffer().find("Double Free"));
// Ensure the crash is only reported once.
GetOutputBuffer().clear();
for (size_t i = 0; i < 100; ++i) {
DeallocateMemory(GPA, Ptr);
ASSERT_TRUE(GetOutputBuffer().empty());
}
}
TEST_P(BacktraceGuardedPoolAllocator, MultipleInvalidFreeOnlyOneOutput) {
SCOPED_TRACE("");
char *Ptr = static_cast<char *>(AllocateMemory(GPA));
// First time should generate a crash report.
DeallocateMemory(GPA, Ptr + 1);
CheckOnlyOneGwpAsanCrash(GetOutputBuffer());
ASSERT_NE(std::string::npos, GetOutputBuffer().find("Invalid (Wild) Free"));
// Ensure the crash is only reported once.
GetOutputBuffer().clear();
for (size_t i = 0; i < 100; ++i) {
DeallocateMemory(GPA, Ptr + 1);
ASSERT_TRUE(GetOutputBuffer().empty());
}
}
TEST_P(BacktraceGuardedPoolAllocator, MultipleUseAfterFreeOnlyOneOutput) {
SCOPED_TRACE("");
void *Ptr = AllocateMemory(GPA);
DeallocateMemory(GPA, Ptr);
// First time should generate a crash report.
TouchMemory(Ptr);
ASSERT_NE(std::string::npos, GetOutputBuffer().find("Use After Free"));
// Ensure the crash is only reported once.
GetOutputBuffer().clear();
for (size_t i = 0; i < 100; ++i) {
TouchMemory(Ptr);
ASSERT_TRUE(GetOutputBuffer().empty());
}
}
TEST_P(BacktraceGuardedPoolAllocator, MultipleBufferOverflowOnlyOneOutput) {
SCOPED_TRACE("");
char *Ptr = static_cast<char *>(AllocateMemory(GPA));
// First time should generate a crash report.
TouchMemory(Ptr - 16);
TouchMemory(Ptr + 16);
CheckOnlyOneGwpAsanCrash(GetOutputBuffer());
if (GetOutputBuffer().find("Buffer Overflow") == std::string::npos &&
GetOutputBuffer().find("Buffer Underflow") == std::string::npos)
FAIL() << "Failed to detect buffer underflow/overflow:\n"
<< GetOutputBuffer();
// Ensure the crash is only reported once.
GetOutputBuffer().clear();
for (size_t i = 0; i < 100; ++i) {
TouchMemory(Ptr - 16);
TouchMemory(Ptr + 16);
ASSERT_TRUE(GetOutputBuffer().empty()) << GetOutputBuffer();
}
}
TEST_P(BacktraceGuardedPoolAllocator, OneDoubleFreeOneUseAfterFree) {
SCOPED_TRACE("");
void *Ptr = AllocateMemory(GPA);
DeallocateMemory(GPA, Ptr);
// First time should generate a crash report.
DeallocateMemory(GPA, Ptr);
CheckOnlyOneGwpAsanCrash(GetOutputBuffer());
ASSERT_NE(std::string::npos, GetOutputBuffer().find("Double Free"));
// Ensure the crash is only reported once.
GetOutputBuffer().clear();
for (size_t i = 0; i < 100; ++i) {
DeallocateMemory(GPA, Ptr);
ASSERT_TRUE(GetOutputBuffer().empty());
}
}
// We use double-free to detect that each slot can generate as single error.
// Use-after-free would also be acceptable, but buffer-overflow wouldn't be, as
// the random left/right alignment means that one right-overflow can disable
// page protections, and a subsequent left-overflow of a slot that's on the
// right hand side may not trap.
TEST_P(BacktraceGuardedPoolAllocator, OneErrorReportPerSlot) {
SCOPED_TRACE("");
std::vector<void *> Ptrs;
for (size_t i = 0; i < GPA.getAllocatorState()->MaxSimultaneousAllocations;
++i) {
void *Ptr = AllocateMemory(GPA);
ASSERT_NE(Ptr, nullptr);
Ptrs.push_back(Ptr);
DeallocateMemory(GPA, Ptr);
DeallocateMemory(GPA, Ptr);
CheckOnlyOneGwpAsanCrash(GetOutputBuffer());
ASSERT_NE(std::string::npos, GetOutputBuffer().find("Double Free"));
// Ensure the crash from this slot is only reported once.
GetOutputBuffer().clear();
DeallocateMemory(GPA, Ptr);
ASSERT_TRUE(GetOutputBuffer().empty());
// Reset the buffer, as we're gonna move to the next allocation.
GetOutputBuffer().clear();
}
// All slots should have been used. No further errors should occur.
for (size_t i = 0; i < 100; ++i)
ASSERT_EQ(AllocateMemory(GPA), nullptr);
for (void *Ptr : Ptrs) {
DeallocateMemory(GPA, Ptr);
TouchMemory(Ptr);
}
ASSERT_TRUE(GetOutputBuffer().empty());
}
void singleAllocThrashTask(gwp_asan::GuardedPoolAllocator *GPA,
std::atomic<bool> *StartingGun,
unsigned NumIterations, unsigned Job, char *Ptr) {
while (!*StartingGun) {
// Wait for starting gun.
}
for (unsigned i = 0; i < NumIterations; ++i) {
switch (Job) {
case 0:
DeallocateMemory(*GPA, Ptr);
break;
case 1:
DeallocateMemory(*GPA, Ptr + 1);
break;
case 2:
TouchMemory(Ptr);
break;
case 3:
TouchMemory(Ptr - 16);
TouchMemory(Ptr + 16);
break;
default:
__builtin_trap();
}
}
}
void runInterThreadThrashingSingleAlloc(unsigned NumIterations,
gwp_asan::GuardedPoolAllocator *GPA) {
std::atomic<bool> StartingGun{false};
std::vector<std::thread> Threads;
constexpr unsigned kNumThreads = 4;
char *Ptr = static_cast<char *>(AllocateMemory(*GPA));
for (unsigned i = 0; i < kNumThreads; ++i) {
Threads.emplace_back(singleAllocThrashTask, GPA, &StartingGun,
NumIterations, i, Ptr);
}
StartingGun = true;
for (auto &T : Threads)
T.join();
}
TEST_P(BacktraceGuardedPoolAllocator, InterThreadThrashingSingleAlloc) {
SCOPED_TRACE("");
constexpr unsigned kNumIterations = 100000;
runInterThreadThrashingSingleAlloc(kNumIterations, &GPA);
CheckOnlyOneGwpAsanCrash(GetOutputBuffer());
}
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