[compiler-rt] r267094 - [sanitizer] Allow the sanitizer allocator to use a non-fixed address range. An allocator with a non-fixed address range will be attack-resistan. NFC for the sanitizers at this point.
Kostya Serebryany via llvm-commits
llvm-commits at lists.llvm.org
Thu Apr 21 18:08:55 PDT 2016
Author: kcc
Date: Thu Apr 21 20:08:54 2016
New Revision: 267094
URL: http://llvm.org/viewvc/llvm-project?rev=267094&view=rev
Log:
[sanitizer] Allow the sanitizer allocator to use a non-fixed address range. An allocator with a non-fixed address range will be attack-resistan. NFC for the sanitizers at this point.
Modified:
compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_testlib.cc
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h?rev=267094&r1=267093&r2=267094&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h Thu Apr 21 20:08:54 2016
@@ -297,9 +297,10 @@ typedef void (*ForEachChunkCallback)(upt
// SizeClassAllocator64 -- allocator for 64-bit address space.
//
-// Space: a portion of address space of kSpaceSize bytes starting at
-// a fixed address (kSpaceBeg). Both constants are powers of two and
-// kSpaceBeg is kSpaceSize-aligned.
+// Space: a portion of address space of kSpaceSize bytes starting at SpaceBeg.
+// If kSpaceBeg is ~0 then SpaceBeg is chosen dynamically my mmap.
+// Otherwise SpaceBeg=kSpaceBeg (fixed address).
+// kSpaceSize is a power of two.
// At the beginning the entire space is mprotect-ed, then small parts of it
// are mapped on demand.
//
@@ -322,9 +323,15 @@ class SizeClassAllocator64 {
typedef SizeClassAllocatorLocalCache<ThisT> AllocatorCache;
void Init() {
- CHECK_EQ(kSpaceBeg,
- reinterpret_cast<uptr>(MmapNoAccess(kSpaceBeg, kSpaceSize)));
- MapWithCallback(kSpaceEnd, AdditionalSize());
+ if (kUsingConstantSpaceBeg) {
+ CHECK_EQ(kSpaceBeg,
+ reinterpret_cast<uptr>(MmapNoAccess(kSpaceBeg, kSpaceSize)));
+ } else {
+ NonConstSpaceBeg = reinterpret_cast<uptr>(
+ MmapNoAccess(0, kSpaceSize + AdditionalSize()));
+ CHECK_NE(NonConstSpaceBeg, ~(uptr)0);
+ }
+ MapWithCallback(SpaceEnd(), AdditionalSize());
}
void MapWithCallback(uptr beg, uptr size) {
@@ -360,12 +367,18 @@ class SizeClassAllocator64 {
region->n_freed += b->count;
}
- static bool PointerIsMine(const void *p) {
- return reinterpret_cast<uptr>(p) / kSpaceSize == kSpaceBeg / kSpaceSize;
+ bool PointerIsMine(const void *p) {
+ uptr P = reinterpret_cast<uptr>(p);
+ if (kUsingConstantSpaceBeg && (kSpaceBeg % kSpaceSize) == 0)
+ return P / kSpaceSize == kSpaceBeg / kSpaceSize;
+ return P >= SpaceBeg() && P < SpaceEnd();
}
- static uptr GetSizeClass(const void *p) {
- return (reinterpret_cast<uptr>(p) / kRegionSize) % kNumClassesRounded;
+ uptr GetSizeClass(const void *p) {
+ if (kUsingConstantSpaceBeg && (kSpaceBeg % kSpaceSize) == 0)
+ return ((reinterpret_cast<uptr>(p)) / kRegionSize) % kNumClassesRounded;
+ return ((reinterpret_cast<uptr>(p) - SpaceBeg()) / kRegionSize) %
+ kNumClassesRounded;
}
void *GetBlockBegin(const void *p) {
@@ -383,7 +396,7 @@ class SizeClassAllocator64 {
return nullptr;
}
- static uptr GetActuallyAllocatedSize(void *p) {
+ uptr GetActuallyAllocatedSize(void *p) {
CHECK(PointerIsMine(p));
return SizeClassMap::Size(GetSizeClass(p));
}
@@ -394,8 +407,9 @@ class SizeClassAllocator64 {
uptr class_id = GetSizeClass(p);
uptr size = SizeClassMap::Size(class_id);
uptr chunk_idx = GetChunkIdx(reinterpret_cast<uptr>(p), size);
- return reinterpret_cast<void*>(kSpaceBeg + (kRegionSize * (class_id + 1)) -
- (1 + chunk_idx) * kMetadataSize);
+ return reinterpret_cast<void *>(SpaceBeg() +
+ (kRegionSize * (class_id + 1)) -
+ (1 + chunk_idx) * kMetadataSize);
}
uptr TotalMemoryUsed() {
@@ -407,7 +421,7 @@ class SizeClassAllocator64 {
// Test-only.
void TestOnlyUnmap() {
- UnmapWithCallback(kSpaceBeg, kSpaceSize + AdditionalSize());
+ UnmapWithCallback(SpaceBeg(), kSpaceSize + AdditionalSize());
}
void PrintStats() {
@@ -455,7 +469,7 @@ class SizeClassAllocator64 {
for (uptr class_id = 1; class_id < kNumClasses; class_id++) {
RegionInfo *region = GetRegionInfo(class_id);
uptr chunk_size = SizeClassMap::Size(class_id);
- uptr region_beg = kSpaceBeg + class_id * kRegionSize;
+ uptr region_beg = SpaceBeg() + class_id * kRegionSize;
for (uptr chunk = region_beg;
chunk < region_beg + region->allocated_user;
chunk += chunk_size) {
@@ -476,8 +490,13 @@ class SizeClassAllocator64 {
private:
static const uptr kRegionSize = kSpaceSize / kNumClassesRounded;
- static const uptr kSpaceEnd = kSpaceBeg + kSpaceSize;
- COMPILER_CHECK(kSpaceBeg % kSpaceSize == 0);
+
+ static const bool kUsingConstantSpaceBeg = kSpaceBeg != ~(uptr)0;
+ uptr NonConstSpaceBeg;
+ uptr SpaceBeg() const {
+ return kUsingConstantSpaceBeg ? kSpaceBeg : NonConstSpaceBeg;
+ }
+ uptr SpaceEnd() const { return SpaceBeg() + kSpaceSize; }
// kRegionSize must be >= 2^32.
COMPILER_CHECK((kRegionSize) >= (1ULL << (SANITIZER_WORDSIZE / 2)));
// Populate the free list with at most this number of bytes at once
@@ -501,7 +520,8 @@ class SizeClassAllocator64 {
RegionInfo *GetRegionInfo(uptr class_id) {
CHECK_LT(class_id, kNumClasses);
- RegionInfo *regions = reinterpret_cast<RegionInfo*>(kSpaceBeg + kSpaceSize);
+ RegionInfo *regions =
+ reinterpret_cast<RegionInfo *>(SpaceBeg() + kSpaceSize);
return ®ions[class_id];
}
@@ -524,7 +544,7 @@ class SizeClassAllocator64 {
uptr count = size < kPopulateSize ? SizeClassMap::MaxCached(class_id) : 1;
uptr beg_idx = region->allocated_user;
uptr end_idx = beg_idx + count * size;
- uptr region_beg = kSpaceBeg + kRegionSize * class_id;
+ uptr region_beg = SpaceBeg() + kRegionSize * class_id;
if (end_idx + size > region->mapped_user) {
// Do the mmap for the user memory.
uptr map_size = kUserMapSize;
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc?rev=267094&r1=267093&r2=267094&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc Thu Apr 21 20:08:54 2016
@@ -272,7 +272,8 @@ void *MmapFixedNoReserve(uptr fixed_addr
void *MmapNoAccess(uptr fixed_addr, uptr size, const char *name) {
int fd = name ? GetNamedMappingFd(name, size) : -1;
- unsigned flags = MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE;
+ unsigned flags = MAP_PRIVATE | MAP_NORESERVE;
+ if (fixed_addr != 0) flags |= MAP_FIXED;
if (fd == -1) flags |= MAP_ANON;
return (void *)internal_mmap((void *)fixed_addr, size, PROT_NONE, flags, fd,
Modified: compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_testlib.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_testlib.cc?rev=267094&r1=267093&r2=267094&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_testlib.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_testlib.cc Thu Apr 21 20:08:54 2016
@@ -37,7 +37,8 @@ namespace {
static const uptr kAllocatorSpace = 0x600000000000ULL;
static const uptr kAllocatorSize = 0x10000000000ULL; // 1T.
-typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, 0,
+typedef SizeClassAllocator64<~(uptr)0, kAllocatorSize, 0,
+// typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, 0,
CompactSizeClassMap> PrimaryAllocator;
typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
typedef LargeMmapAllocator<> SecondaryAllocator;
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