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/* -*- 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
#include "mozilla/Literals.h"
#include "mozilla/mozalloc.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Unused.h"
#include "mozilla/Vector.h"
#include "mozilla/gtest/MozHelpers.h"
#include "mozmemory.h"
#include "nsCOMPtr.h"
#include "Utils.h"
#include "gtest/gtest.h"
#ifdef MOZ_PHC
# include "PHC.h"
#endif
using namespace mozilla;
class AutoDisablePHCOnCurrentThread {
public:
AutoDisablePHCOnCurrentThread() {
#ifdef MOZ_PHC
mozilla::phc::DisablePHCOnCurrentThread();
#endif
}
~AutoDisablePHCOnCurrentThread() {
#ifdef MOZ_PHC
mozilla::phc::ReenablePHCOnCurrentThread();
#endif
}
};
static inline void TestOne(size_t size) {
size_t req = size;
size_t adv = malloc_good_size(req);
char* p = (char*)malloc(req);
size_t usable = moz_malloc_usable_size(p);
// NB: Using EXPECT here so that we still free the memory on failure.
EXPECT_EQ(adv, usable) << "malloc_good_size(" << req << ") --> " << adv
<< "; "
"malloc_usable_size("
<< req << ") --> " << usable;
free(p);
}
static inline void TestThree(size_t size) {
ASSERT_NO_FATAL_FAILURE(TestOne(size - 1));
ASSERT_NO_FATAL_FAILURE(TestOne(size));
ASSERT_NO_FATAL_FAILURE(TestOne(size + 1));
}
TEST(Jemalloc, UsableSizeInAdvance)
{
/*
* Test every size up to a certain point, then (N-1, N, N+1) triplets for a
* various sizes beyond that.
*/
for (size_t n = 0; n < 16_KiB; n++) ASSERT_NO_FATAL_FAILURE(TestOne(n));
for (size_t n = 16_KiB; n < 1_MiB; n += 4_KiB)
ASSERT_NO_FATAL_FAILURE(TestThree(n));
for (size_t n = 1_MiB; n < 8_MiB; n += 128_KiB)
ASSERT_NO_FATAL_FAILURE(TestThree(n));
}
static int gStaticVar;
bool InfoEq(jemalloc_ptr_info_t& aInfo, PtrInfoTag aTag, void* aAddr,
size_t aSize, arena_id_t arenaId) {
return aInfo.tag == aTag && aInfo.addr == aAddr && aInfo.size == aSize
#ifdef MOZ_DEBUG
&& aInfo.arenaId == arenaId
#endif
;
}
bool InfoEqFreedPage(jemalloc_ptr_info_t& aInfo, void* aAddr, size_t aPageSize,
arena_id_t arenaId) {
size_t pageSizeMask = aPageSize - 1;
return jemalloc_ptr_is_freed_page(&aInfo) &&
aInfo.addr == (void*)(uintptr_t(aAddr) & ~pageSizeMask) &&
aInfo.size == aPageSize
#ifdef MOZ_DEBUG
&& aInfo.arenaId == arenaId
#endif
;
}
TEST(Jemalloc, PtrInfo)
{
arena_id_t arenaId = moz_create_arena();
ASSERT_TRUE(arenaId != 0);
jemalloc_stats_t stats;
jemalloc_stats(&stats);
jemalloc_ptr_info_t info;
Vector<char*> small, large, huge;
// For small (less than half the page size) allocations, test every position
// within many possible sizes.
size_t small_max =
stats.subpage_max ? stats.subpage_max : stats.quantum_wide_max;
for (size_t n = 0; n <= small_max; n += 8) {
auto p = (char*)moz_arena_malloc(arenaId, n);
size_t usable = moz_malloc_size_of(p);
ASSERT_TRUE(small.append(p));
for (size_t j = 0; j < usable; j++) {
jemalloc_ptr_info(&p[j], &info);
ASSERT_TRUE(InfoEq(info, TagLiveAlloc, p, usable, arenaId));
}
}
// Similar for large (small_max + 1 KiB .. 1MiB - 8KiB) allocations.
for (size_t n = small_max + 1_KiB; n <= stats.large_max; n += 1_KiB) {
auto p = (char*)moz_arena_malloc(arenaId, n);
size_t usable = moz_malloc_size_of(p);
ASSERT_TRUE(large.append(p));
for (size_t j = 0; j < usable; j += 347) {
jemalloc_ptr_info(&p[j], &info);
ASSERT_TRUE(InfoEq(info, TagLiveAlloc, p, usable, arenaId));
}
}
// Similar for huge (> 1MiB - 8KiB) allocations.
for (size_t n = stats.chunksize; n <= 10_MiB; n += 512_KiB) {
auto p = (char*)moz_arena_malloc(arenaId, n);
size_t usable = moz_malloc_size_of(p);
ASSERT_TRUE(huge.append(p));
for (size_t j = 0; j < usable; j += 567) {
jemalloc_ptr_info(&p[j], &info);
ASSERT_TRUE(InfoEq(info, TagLiveAlloc, p, usable, arenaId));
}
}
// The following loops check freed allocations. We step through the vectors
// using prime-sized steps, which gives full coverage of the arrays while
// avoiding deallocating in the same order we allocated.
size_t len;
// Free the small allocations and recheck them.
int isFreedAlloc = 0, isFreedPage = 0;
len = small.length();
for (size_t i = 0, j = 0; i < len; i++, j = (j + 19) % len) {
char* p = small[j];
size_t usable = moz_malloc_size_of(p);
free(p);
for (size_t k = 0; k < usable; k++) {
jemalloc_ptr_info(&p[k], &info);
// There are two valid outcomes here.
if (InfoEq(info, TagFreedAlloc, p, usable, arenaId)) {
isFreedAlloc++;
} else if (InfoEqFreedPage(info, &p[k], stats.page_size, arenaId)) {
isFreedPage++;
} else {
ASSERT_TRUE(false);
}
}
}
// There should be both FreedAlloc and FreedPage results, but a lot more of
// the former.
ASSERT_TRUE(isFreedAlloc != 0);
ASSERT_TRUE(isFreedPage != 0);
ASSERT_TRUE(isFreedAlloc / isFreedPage > 8);
// Free the large allocations and recheck them.
len = large.length();
for (size_t i = 0, j = 0; i < len; i++, j = (j + 31) % len) {
char* p = large[j];
size_t usable = moz_malloc_size_of(p);
free(p);
for (size_t k = 0; k < usable; k += 357) {
jemalloc_ptr_info(&p[k], &info);
ASSERT_TRUE(InfoEqFreedPage(info, &p[k], stats.page_size, arenaId));
}
}
// Free the huge allocations and recheck them.
len = huge.length();
for (size_t i = 0, j = 0; i < len; i++, j = (j + 7) % len) {
char* p = huge[j];
size_t usable = moz_malloc_size_of(p);
free(p);
for (size_t k = 0; k < usable; k += 587) {
jemalloc_ptr_info(&p[k], &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
}
}
// Null ptr.
jemalloc_ptr_info(nullptr, &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
// Near-null ptr.
jemalloc_ptr_info((void*)0x123, &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
// Maximum address.
jemalloc_ptr_info((void*)uintptr_t(-1), &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
// Stack memory.
int stackVar;
jemalloc_ptr_info(&stackVar, &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
// Code memory.
jemalloc_ptr_info((const void*)&jemalloc_ptr_info, &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
// Static memory.
jemalloc_ptr_info(&gStaticVar, &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
// Chunk header.
UniquePtr<int> p = MakeUnique<int>();
size_t chunksizeMask = stats.chunksize - 1;
char* chunk = (char*)(uintptr_t(p.get()) & ~chunksizeMask);
size_t chunkHeaderSize = stats.chunksize - stats.large_max - stats.page_size;
for (size_t i = 0; i < chunkHeaderSize; i += 64) {
jemalloc_ptr_info(&chunk[i], &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
}
// Run header.
size_t page_sizeMask = stats.page_size - 1;
char* run = (char*)(uintptr_t(p.get()) & ~page_sizeMask);
for (size_t i = 0; i < 4 * sizeof(void*); i++) {
jemalloc_ptr_info(&run[i], &info);
ASSERT_TRUE(InfoEq(info, TagUnknown, nullptr, 0U, 0U));
}
// Entire chunk. It's impossible to check what is put into |info| for all of
// these addresses; this is more about checking that we don't crash.
for (size_t i = 0; i < stats.chunksize; i += 256) {
jemalloc_ptr_info(&chunk[i], &info);
}
moz_dispose_arena(arenaId);
}
size_t sSizes[] = {1, 42, 79, 918, 1.4_KiB,
73_KiB, 129_KiB, 1.1_MiB, 2.6_MiB, 5.1_MiB};
TEST(Jemalloc, Arenas)
{
arena_id_t arena = moz_create_arena();
ASSERT_TRUE(arena != 0);
void* ptr = moz_arena_malloc(arena, 42);
ASSERT_TRUE(ptr != nullptr);
ptr = moz_arena_realloc(arena, ptr, 64);
ASSERT_TRUE(ptr != nullptr);
moz_arena_free(arena, ptr);
ptr = moz_arena_calloc(arena, 24, 2);
// For convenience, free can be used to free arena pointers.
free(ptr);
moz_dispose_arena(arena);
// Avoid death tests adding some unnecessary (long) delays.
SAVE_GDB_SLEEP_LOCAL();
// Can't use an arena after it's disposed.
// ASSERT_DEATH_WRAP(moz_arena_malloc(arena, 80), "");
// Arena id 0 can't be used to somehow get to the main arena.
ASSERT_DEATH_WRAP(moz_arena_malloc(0, 80), "");
arena = moz_create_arena();
arena_id_t arena2 = moz_create_arena();
// Ensure arena2 is used to prevent OSX errors:
(void)arena2;
// For convenience, realloc can also be used to reallocate arena pointers.
// The result should be in the same arena. Test various size class
// transitions.
for (size_t from_size : sSizes) {
SCOPED_TRACE(testing::Message() << "from_size = " << from_size);
for (size_t to_size : sSizes) {
SCOPED_TRACE(testing::Message() << "to_size = " << to_size);
ptr = moz_arena_malloc(arena, from_size);
ptr = realloc(ptr, to_size);
// Freeing with the wrong arena should crash.
ASSERT_DEATH_WRAP(moz_arena_free(arena2, ptr), "");
// Likewise for moz_arena_realloc.
ASSERT_DEATH_WRAP(moz_arena_realloc(arena2, ptr, from_size), "");
// The following will crash if it's not in the right arena.
moz_arena_free(arena, ptr);
}
}
moz_dispose_arena(arena2);
moz_dispose_arena(arena);
RESTORE_GDB_SLEEP_LOCAL();
}
// Check that a buffer aPtr is entirely filled with a given character from
// aOffset to aSize. For faster comparison, the caller is required to fill a
// reference buffer with the wanted character, and give the size of that
// reference buffer.
static void bulk_compare(char* aPtr, size_t aOffset, size_t aSize,
char* aReference, size_t aReferenceSize) {
for (size_t i = aOffset; i < aSize; i += aReferenceSize) {
size_t length = std::min(aSize - i, aReferenceSize);
if (memcmp(aPtr + i, aReference, length)) {
// We got a mismatch, we now want to report more precisely where.
for (size_t j = i; j < i + length; j++) {
ASSERT_EQ(aPtr[j], *aReference);
}
}
}
}
// A range iterator for size classes between two given values.
class SizeClassesBetween {
public:
SizeClassesBetween(size_t aStart, size_t aEnd) : mStart(aStart), mEnd(aEnd) {}
class Iterator {
public:
explicit Iterator(size_t aValue) : mValue(malloc_good_size(aValue)) {}
operator size_t() const { return mValue; }
size_t operator*() const { return mValue; }
Iterator& operator++() {
mValue = malloc_good_size(mValue + 1);
return *this;
}
private:
size_t mValue;
};
Iterator begin() { return Iterator(mStart); }
Iterator end() { return Iterator(mEnd); }
private:
size_t mStart, mEnd;
};
#define ALIGNMENT_CEILING(s, alignment) \
(((s) + ((alignment)-1)) & (~((alignment)-1)))
#define ALIGNMENT_FLOOR(s, alignment) ((s) & (~((alignment)-1)))
static bool IsSameRoundedHugeClass(size_t aSize1, size_t aSize2,
jemalloc_stats_t& aStats) {
return (aSize1 > aStats.large_max && aSize2 > aStats.large_max &&
ALIGNMENT_CEILING(aSize1 + aStats.page_size, aStats.chunksize) ==
ALIGNMENT_CEILING(aSize2 + aStats.page_size, aStats.chunksize));
}
static bool CanReallocInPlace(size_t aFromSize, size_t aToSize,
jemalloc_stats_t& aStats) {
// PHC allocations must be disabled because PHC reallocs differently to
// mozjemalloc.
#ifdef MOZ_PHC
MOZ_RELEASE_ASSERT(!mozilla::phc::IsPHCEnabledOnCurrentThread());
#endif
if (aFromSize == malloc_good_size(aToSize)) {
// Same size class: in-place.
return true;
}
if (aFromSize >= aStats.page_size && aFromSize <= aStats.large_max &&
aToSize >= aStats.page_size && aToSize <= aStats.large_max) {
// Any large class to any large class: in-place when there is space to.
return true;
}
if (IsSameRoundedHugeClass(aFromSize, aToSize, aStats)) {
// Huge sizes that round up to the same multiple of the chunk size:
// in-place.
return true;
}
return false;
}
TEST(Jemalloc, InPlace)
{
// Disable PHC allocations for this test, because CanReallocInPlace() isn't
// valid for PHC allocations.
AutoDisablePHCOnCurrentThread disable;
jemalloc_stats_t stats;
jemalloc_stats(&stats);
// Using a separate arena, which is always emptied after an iteration, ensures
// that in-place reallocation happens in all cases it can happen. This test is
// intended for developers to notice they may have to adapt other tests if
// they change the conditions for in-place reallocation.
arena_id_t arena = moz_create_arena();
for (size_t from_size : SizeClassesBetween(1, 2 * stats.chunksize)) {
SCOPED_TRACE(testing::Message() << "from_size = " << from_size);
for (size_t to_size : sSizes) {
SCOPED_TRACE(testing::Message() << "to_size = " << to_size);
char* ptr = (char*)moz_arena_malloc(arena, from_size);
char* ptr2 = (char*)moz_arena_realloc(arena, ptr, to_size);
if (CanReallocInPlace(from_size, to_size, stats)) {
EXPECT_EQ(ptr, ptr2);
} else {
EXPECT_NE(ptr, ptr2);
}
moz_arena_free(arena, ptr2);
}
}
moz_dispose_arena(arena);
}
// timeout.
#if !defined(XP_WIN) || !defined(MOZ_CODE_COVERAGE)
TEST(Jemalloc, JunkPoison)
{
// Disable PHC allocations for this test, because CanReallocInPlace() isn't
// valid for PHC allocations, and the testing UAFs aren't valid.
AutoDisablePHCOnCurrentThread disable;
jemalloc_stats_t stats;
jemalloc_stats(&stats);
// Avoid death tests adding some unnecessary (long) delays.
SAVE_GDB_SLEEP_LOCAL();
// Create buffers in a separate arena, for faster comparisons with
// bulk_compare.
arena_id_t buf_arena = moz_create_arena();
char* junk_buf = (char*)moz_arena_malloc(buf_arena, stats.page_size);
// Depending on its configuration, the allocator will either fill the
// requested allocation with the junk byte (0xe4) or with zeroes, or do
// nothing, in which case, since we're allocating in a fresh arena,
// we'll be getting zeroes.
char junk = stats.opt_junk ? '\xe4' : '\0';
for (size_t i = 0; i < stats.page_size; i++) {
ASSERT_EQ(junk_buf[i], junk);
}
char* poison_buf = (char*)moz_arena_malloc(buf_arena, stats.page_size);
memset(poison_buf, 0xe5, stats.page_size);
static const char fill = 0x42;
char* fill_buf = (char*)moz_arena_malloc(buf_arena, stats.page_size);
memset(fill_buf, fill, stats.page_size);
arena_params_t params;
// Allow as many dirty pages in the arena as possible, so that purge never
// happens in it. Purge breaks some of the tests below randomly depending on
// what other things happen on other threads.
params.mMaxDirty = size_t(-1);
arena_id_t arena = moz_create_arena_with_params(¶ms);
// Mozjemalloc is configured to only poison the first four cache lines.
const size_t poison_check_len = 256;
// Allocating should junk the buffer, and freeing should poison the buffer.
for (size_t size : sSizes) {
if (size <= stats.large_max) {
SCOPED_TRACE(testing::Message() << "size = " << size);
char* buf = (char*)moz_arena_malloc(arena, size);
size_t allocated = moz_malloc_usable_size(buf);
if (stats.opt_junk || stats.opt_zero) {
ASSERT_NO_FATAL_FAILURE(
bulk_compare(buf, 0, allocated, junk_buf, stats.page_size));
}
moz_arena_free(arena, buf);
// We purposefully do a use-after-free here, to check that the data was
// poisoned.
ASSERT_NO_FATAL_FAILURE(
bulk_compare(buf, 0, std::min(allocated, poison_check_len),
poison_buf, stats.page_size));
}
}
// Shrinking in the same size class should be in place and poison between the
// new allocation size and the old one.
size_t prev = 0;
for (size_t size : SizeClassesBetween(1, 2 * stats.chunksize)) {
SCOPED_TRACE(testing::Message() << "size = " << size);
SCOPED_TRACE(testing::Message() << "prev = " << prev);
char* ptr = (char*)moz_arena_malloc(arena, size);
memset(ptr, fill, moz_malloc_usable_size(ptr));
char* ptr2 = (char*)moz_arena_realloc(arena, ptr, prev + 1);
ASSERT_EQ(ptr, ptr2);
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr, 0, prev + 1, fill_buf, stats.page_size));
ASSERT_NO_FATAL_FAILURE(bulk_compare(ptr, prev + 1,
std::min(size, poison_check_len),
poison_buf, stats.page_size));
moz_arena_free(arena, ptr);
prev = size;
}
// In-place realloc should junk the new bytes when growing and poison the old
// bytes when shrinking.
for (size_t from_size : SizeClassesBetween(1, 2 * stats.chunksize)) {
SCOPED_TRACE(testing::Message() << "from_size = " << from_size);
for (size_t to_size : sSizes) {
SCOPED_TRACE(testing::Message() << "to_size = " << to_size);
if (CanReallocInPlace(from_size, to_size, stats)) {
char* ptr = (char*)moz_arena_malloc(arena, from_size);
memset(ptr, fill, moz_malloc_usable_size(ptr));
char* ptr2 = (char*)moz_arena_realloc(arena, ptr, to_size);
ASSERT_EQ(ptr, ptr2);
// Shrinking allocation
if (from_size >= to_size) {
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr, 0, to_size, fill_buf, stats.page_size));
// Huge allocations have guards and will crash when accessing
// beyond the valid range.
if (to_size > stats.large_max) {
size_t page_limit = ALIGNMENT_CEILING(to_size, stats.page_size);
ASSERT_NO_FATAL_FAILURE(bulk_compare(
ptr, to_size, std::min(page_limit, poison_check_len),
poison_buf, stats.page_size));
ASSERT_DEATH_WRAP(ptr[page_limit] = 0, "");
} else {
ASSERT_NO_FATAL_FAILURE(bulk_compare(
ptr, to_size, std::min(from_size, poison_check_len), poison_buf,
stats.page_size));
}
} else {
// Enlarging allocation
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr, 0, from_size, fill_buf, stats.page_size));
if (stats.opt_junk || stats.opt_zero) {
ASSERT_NO_FATAL_FAILURE(bulk_compare(ptr, from_size, to_size,
junk_buf, stats.page_size));
}
// Huge allocation, so should have a guard page following
if (to_size > stats.large_max) {
ASSERT_DEATH_WRAP(
ptr[ALIGNMENT_CEILING(to_size, stats.page_size)] = 0, "");
}
}
moz_arena_free(arena, ptr2);
}
}
}
// Growing to a different size class should poison the old allocation,
// preserve the original bytes, and junk the new bytes in the new allocation.
for (size_t from_size : SizeClassesBetween(1, 2 * stats.chunksize)) {
SCOPED_TRACE(testing::Message() << "from_size = " << from_size);
for (size_t to_size : sSizes) {
if (from_size < to_size && malloc_good_size(to_size) != from_size &&
!IsSameRoundedHugeClass(from_size, to_size, stats)) {
SCOPED_TRACE(testing::Message() << "to_size = " << to_size);
char* ptr = (char*)moz_arena_malloc(arena, from_size);
memset(ptr, fill, moz_malloc_usable_size(ptr));
// Avoid in-place realloc by allocating a buffer, expecting it to be
// right after the buffer we just received. Buffers smaller than the
// page size and exactly or larger than the size of the largest large
// size class can't be reallocated in-place.
char* avoid_inplace = nullptr;
if (from_size >= stats.page_size && from_size < stats.large_max) {
avoid_inplace = (char*)moz_arena_malloc(arena, stats.page_size);
ASSERT_EQ(ptr + from_size, avoid_inplace);
}
char* ptr2 = (char*)moz_arena_realloc(arena, ptr, to_size);
ASSERT_NE(ptr, ptr2);
if (from_size <= stats.large_max) {
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr, 0, std::min(from_size, poison_check_len),
poison_buf, stats.page_size));
}
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr2, 0, from_size, fill_buf, stats.page_size));
if (stats.opt_junk || stats.opt_zero) {
size_t rounded_to_size = malloc_good_size(to_size);
ASSERT_NE(to_size, rounded_to_size);
ASSERT_NO_FATAL_FAILURE(bulk_compare(ptr2, from_size, rounded_to_size,
junk_buf, stats.page_size));
}
moz_arena_free(arena, ptr2);
moz_arena_free(arena, avoid_inplace);
}
}
}
// Shrinking to a different size class should poison the old allocation,
// preserve the original bytes, and junk the extra bytes in the new
// allocation.
for (size_t from_size : SizeClassesBetween(1, 2 * stats.chunksize)) {
SCOPED_TRACE(testing::Message() << "from_size = " << from_size);
for (size_t to_size : sSizes) {
if (from_size > to_size &&
!CanReallocInPlace(from_size, to_size, stats)) {
SCOPED_TRACE(testing::Message() << "to_size = " << to_size);
char* ptr = (char*)moz_arena_malloc(arena, from_size);
memset(ptr, fill, from_size);
char* ptr2 = (char*)moz_arena_realloc(arena, ptr, to_size);
ASSERT_NE(ptr, ptr2);
if (from_size <= stats.large_max) {
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr, 0, std::min(from_size, poison_check_len),
poison_buf, stats.page_size));
}
ASSERT_NO_FATAL_FAILURE(
bulk_compare(ptr2, 0, to_size, fill_buf, stats.page_size));
if (stats.opt_junk || stats.opt_zero) {
size_t rounded_to_size = malloc_good_size(to_size);
ASSERT_NE(to_size, rounded_to_size);
ASSERT_NO_FATAL_FAILURE(bulk_compare(ptr2, from_size, rounded_to_size,
junk_buf, stats.page_size));
}
moz_arena_free(arena, ptr2);
}
}
}
moz_dispose_arena(arena);
moz_arena_free(buf_arena, poison_buf);
moz_arena_free(buf_arena, junk_buf);
moz_arena_free(buf_arena, fill_buf);
moz_dispose_arena(buf_arena);
RESTORE_GDB_SLEEP_LOCAL();
}
#endif // !defined(XP_WIN) || !defined(MOZ_CODE_COVERAGE)
TEST(Jemalloc, TrailingGuard)
{
// Disable PHC allocations for this test, because even a single PHC
// allocation occurring can throw it off.
AutoDisablePHCOnCurrentThread disable;
jemalloc_stats_t stats;
jemalloc_stats(&stats);
// Avoid death tests adding some unnecessary (long) delays.
SAVE_GDB_SLEEP_LOCAL();
arena_id_t arena = moz_create_arena();
ASSERT_TRUE(arena != 0);
// Do enough large allocations to fill a chunk, and then one additional one,
// and check that the guard page is still present after the one-but-last
// allocation, i.e. that we didn't allocate the guard.
Vector<void*> ptr_list;
for (size_t cnt = 0; cnt < stats.large_max / stats.page_size; cnt++) {
void* ptr = moz_arena_malloc(arena, stats.page_size);
ASSERT_TRUE(ptr != nullptr);
ASSERT_TRUE(ptr_list.append(ptr));
}
void* last_ptr_in_chunk = ptr_list[ptr_list.length() - 1];
void* extra_ptr = moz_arena_malloc(arena, stats.page_size);
void* guard_page = (void*)ALIGNMENT_CEILING(
(uintptr_t)last_ptr_in_chunk + stats.page_size, stats.page_size);
jemalloc_ptr_info_t info;
jemalloc_ptr_info(guard_page, &info);
ASSERT_TRUE(jemalloc_ptr_is_freed_page(&info));
ASSERT_DEATH_WRAP(*(char*)guard_page = 0, "");
for (void* ptr : ptr_list) {
moz_arena_free(arena, ptr);
}
moz_arena_free(arena, extra_ptr);
moz_dispose_arena(arena);
RESTORE_GDB_SLEEP_LOCAL();
}
TEST(Jemalloc, LeadingGuard)
{
// Disable PHC allocations for this test, because even a single PHC
// allocation occurring can throw it off.
AutoDisablePHCOnCurrentThread disable;
jemalloc_stats_t stats;
jemalloc_stats(&stats);
// Avoid death tests adding some unnecessary (long) delays.
SAVE_GDB_SLEEP_LOCAL();
arena_id_t arena = moz_create_arena();
ASSERT_TRUE(arena != 0);
// Do a simple normal allocation, but force all the allocation space
// in the chunk to be used up. This allows us to check that we get
// the safe area right in the logic that follows (all memory will be
// committed and initialized), and it forces this pointer to the start
// of the zone to sit at the very start of the usable chunk area.
void* ptr = moz_arena_malloc(arena, stats.large_max);
ASSERT_TRUE(ptr != nullptr);
// If ptr is chunk-aligned, the above allocation went wrong.
void* chunk_start = (void*)ALIGNMENT_FLOOR((uintptr_t)ptr, stats.chunksize);
ASSERT_NE((uintptr_t)ptr, (uintptr_t)chunk_start);
// If ptr is 1 page after the chunk start (so right after the header),
// we must have missed adding the guard page.
ASSERT_NE((uintptr_t)ptr, (uintptr_t)chunk_start + stats.page_size);
// The actual start depends on the amount of metadata versus the page
// size, so we can't check equality without pulling in too many
// implementation details.
// Guard page should be right before data area
void* guard_page = (void*)(((uintptr_t)ptr) - sizeof(void*));
jemalloc_ptr_info_t info;
jemalloc_ptr_info(guard_page, &info);
ASSERT_TRUE(info.tag == TagUnknown);
ASSERT_DEATH_WRAP(*(char*)guard_page = 0, "");
moz_arena_free(arena, ptr);
moz_dispose_arena(arena);
RESTORE_GDB_SLEEP_LOCAL();
}
TEST(Jemalloc, DisposeArena)
{
jemalloc_stats_t stats;
jemalloc_stats(&stats);
// Avoid death tests adding some unnecessary (long) delays.
SAVE_GDB_SLEEP_LOCAL();
arena_id_t arena = moz_create_arena();
void* ptr = moz_arena_malloc(arena, 42);
// Disposing of the arena when it's not empty is a MOZ_CRASH-worthy error.
ASSERT_DEATH_WRAP(moz_dispose_arena(arena), "");
moz_arena_free(arena, ptr);
moz_dispose_arena(arena);
arena = moz_create_arena();
ptr = moz_arena_malloc(arena, stats.page_size * 2);
// Disposing of the arena when it's not empty is a MOZ_CRASH-worthy error.
ASSERT_DEATH_WRAP(moz_dispose_arena(arena), "");
moz_arena_free(arena, ptr);
moz_dispose_arena(arena);
arena = moz_create_arena();
ptr = moz_arena_malloc(arena, stats.chunksize * 2);
#ifdef MOZ_DEBUG
// On debug builds, we do the expensive check that arenas are empty.
ASSERT_DEATH_WRAP(moz_dispose_arena(arena), "");
moz_arena_free(arena, ptr);
moz_dispose_arena(arena);
#else
// Currently, the allocator can't trivially check whether the arena is empty
// of huge allocations, so disposing of it works.
moz_dispose_arena(arena);
// But trying to free a pointer that belongs to it will MOZ_CRASH.
ASSERT_DEATH_WRAP(free(ptr), "");
// Likewise for realloc
ASSERT_DEATH_WRAP(ptr = realloc(ptr, stats.chunksize * 3), "");
#endif
// Using the arena after it's been disposed of is MOZ_CRASH-worthy.
ASSERT_DEATH_WRAP(moz_arena_malloc(arena, 42), "");
RESTORE_GDB_SLEEP_LOCAL();
}