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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Attributes.h"
#include "mozilla/Function.h"
#include "mozilla/mozalloc.h"
#include "mozilla/ScopeExit.h"
#include "nsCOMPtr.h"
#include "nsIMemoryReporter.h"
#include "nsServiceManagerUtils.h"
#include "gtest/gtest.h"
// We want to ensure that various functions are hooked properly and that
// allocations are getting routed through jemalloc. The strategy
// pursued below relies on jemalloc's statistics tracking: we measure
// the size of the jemalloc heap using nsIMemoryReporterManager,
// allocate a chunk of memory with whatever function is supposed to be
// hooked, and then ask for the size of the jemalloc heap again. If the
// function has been hooked correctly, then the heap size should be
// different between the two measurements. We can also check the
// hooking of |free| and similar functions: once we free() the returned
// pointer, we can measure the jemalloc heap size again, expecting it to
// be identical to the size prior to the allocation.
//
// If we're not using jemalloc, then nsIMemoryReporterManager will
// simply report an error, and we will ignore the entire test.
//
// This strategy is not perfect: it relies on GTests being
// single-threaded, which they are, and no other threads doing
// allocation during the test, which is uncertain, as XPCOM has started
// up during gtests, and who knows what might be going on behind the
// scenes. This latter assumption, however, does not seem to be a
// problem in practice.
#if defined(MOZ_MEMORY)
#define ALLOCATION_ASSERT(b) ASSERT_TRUE((b))
#else
#define ALLOCATION_ASSERT(b) (void)(b)
#endif
#define ASSERT_ALLOCATION_HAPPENED(lambda) \
ALLOCATION_ASSERT(ValidateHookedAllocation(lambda, free));
// We do run the risk of OOM'ing when we allocate something...all we can
// do is try to allocate something so small that OOM'ing is unlikely.
const size_t kAllocAmount = 16;
// We declare this function MOZ_NEVER_INLINE to work around optimizing
// compilers. If we permitted inlining here, then the compiler might
// inline both this function and the calls to the function pointers we
// pass in, giving something like:
//
// void* p = malloc(...);
// ...do nothing with p except check nullptr-ness...
// free(p);
//
// and the optimizer can delete the calls to malloc and free entirely,
// which would make checking that the jemalloc heap had never changed
// difficult.
static MOZ_NEVER_INLINE bool
ValidateHookedAllocation(void* (*aAllocator)(void),
void (*aFreeFunction)(void*))
{
nsCOMPtr<nsIMemoryReporterManager> manager =
do_GetService("@mozilla.org/memory-reporter-manager;1");
int64_t before = 0;
nsresult rv = manager->GetHeapAllocated(&before);
if (NS_FAILED(rv)) {
return false;
}
{
void* p = aAllocator();
if (!p) {
return false;
}
int64_t after = 0;
rv = manager->GetHeapAllocated(&after);
// Regardless of whether that call succeeded or failed, we are done with
// the allocated buffer now.
aFreeFunction(p);
if (NS_FAILED(rv)) {
return false;
}
// Verify that our heap stats have changed.
if ((before + int64_t(kAllocAmount)) != after) {
return false;
}
}
// Verify that freeing the allocated pointer resets our heap to what it
// was before.
int64_t after = 0;
rv = manager->GetHeapAllocated(&after);
if (NS_FAILED(rv)) {
return false;
}
return before == after;
}
TEST(AllocReplacement, malloc_check)
{
ASSERT_ALLOCATION_HAPPENED([] {
return malloc(kAllocAmount);
});
}
TEST(AllocReplacement, calloc_check)
{
ASSERT_ALLOCATION_HAPPENED([] {
return calloc(1, kAllocAmount);
});
}
TEST(AllocReplacement, realloc_check)
{
ASSERT_ALLOCATION_HAPPENED([] {
return realloc(nullptr, kAllocAmount);
});
}
#if defined(HAVE_POSIX_MEMALIGN)
TEST(AllocReplacement, posix_memalign_check)
{
ASSERT_ALLOCATION_HAPPENED([] {
void* p = nullptr;
int result = posix_memalign(&p, sizeof(void*), kAllocAmount);
if (result != 0) {
return static_cast<void*>(nullptr);
}
return p;
});
}
#endif
#if defined(XP_WIN)
#include <windows.h>
#undef ASSERT_ALLOCATION_HAPPENED
#define ASSERT_ALLOCATION_HAPPENED(lambda) \
ALLOCATION_ASSERT(ValidateHookedAllocation(lambda, [](void* p) { \
HeapFree(GetProcessHeap(), 0, p); \
}));
TEST(AllocReplacement, HeapAlloc_check)
{
ASSERT_ALLOCATION_HAPPENED([] {
HANDLE h = GetProcessHeap();
return HeapAlloc(h, 0, kAllocAmount);
});
}
TEST(AllocReplacement, HeapReAlloc_check)
{
ASSERT_ALLOCATION_HAPPENED([] {
HANDLE h = GetProcessHeap();
void *p = HeapAlloc(h, 0, kAllocAmount / 2);
if (!p) {
return static_cast<void*>(nullptr);
}
return HeapReAlloc(h, 0, p, kAllocAmount);
});
}
#endif
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