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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /xpcom/tests/gtest/TestAllocReplacement.cpp | |
parent | Initial commit. (diff) | |
download | firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/tests/gtest/TestAllocReplacement.cpp')
-rw-r--r-- | xpcom/tests/gtest/TestAllocReplacement.cpp | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestAllocReplacement.cpp b/xpcom/tests/gtest/TestAllocReplacement.cpp new file mode 100644 index 0000000000..87318d2351 --- /dev/null +++ b/xpcom/tests/gtest/TestAllocReplacement.cpp @@ -0,0 +1,177 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/mozalloc.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; +} + +// We use the "*DeathTest" suffix for all tests in this file to ensure they +// run before other GTests. As noted at the top, this is important because +// other tests might spawn threads that interfere with heap memory +// measurements. +// +// See +// <https://github.com/google/googletest/blob/master/googletest/docs/AdvancedGuide.md#death-tests> +// for more information about death tests in the GTest framework. +TEST(AllocReplacementDeathTest, malloc_check) +{ + ASSERT_ALLOCATION_HAPPENED([] { return malloc(kAllocAmount); }); +} + +// See above for an explanation of the "*DeathTest" suffix used here. +TEST(AllocReplacementDeathTest, calloc_check) +{ + ASSERT_ALLOCATION_HAPPENED([] { return calloc(1, kAllocAmount); }); +} + +// See above for an explanation of the "*DeathTest" suffix used here. +TEST(AllocReplacementDeathTest, realloc_check) +{ + ASSERT_ALLOCATION_HAPPENED([] { return realloc(nullptr, kAllocAmount); }); +} + +#if defined(HAVE_POSIX_MEMALIGN) +// See above for an explanation of the "*DeathTest" suffix used here. +TEST(AllocReplacementDeathTest, 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); })); + +// See above for an explanation of the "*DeathTest" suffix used here. +TEST(AllocReplacementDeathTest, HeapAlloc_check) +{ + ASSERT_ALLOCATION_HAPPENED([] { + HANDLE h = GetProcessHeap(); + return HeapAlloc(h, 0, kAllocAmount); + }); +} + +// See above for an explanation of the "*DeathTest" suffix used here. +TEST(AllocReplacementDeathTest, 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 |