[compiler-rt] dbf04aa - Revert "[Asan] Cleanup atomic usage in allocator"
Nico Weber via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 4 07:51:21 PDT 2020
Author: Nico Weber
Date: 2020-09-04T10:51:08-04:00
New Revision: dbf04aaade235a0d76c6ad549c091c9fd0ada0e8
URL: https://github.com/llvm/llvm-project/commit/dbf04aaade235a0d76c6ad549c091c9fd0ada0e8
DIFF: https://github.com/llvm/llvm-project/commit/dbf04aaade235a0d76c6ad549c091c9fd0ada0e8.diff
LOG: Revert "[Asan] Cleanup atomic usage in allocator"
This reverts commit 8b8be6f38ab568d40869205389a002f32f6558a2
and follow-ups 99a93c3a223e3bfc9a9781bfbf98d2fd4551f923,
a9c0bf04043462d43013bc5616aa48f6d3e16b88,
48ac5b4833b60f00f0923db11ea31e7316bc78c6.
It breaks building on Windows, see https://reviews.llvm.org/D86917#2255872
Added:
Modified:
compiler-rt/lib/asan/asan_allocator.cpp
compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
Removed:
################################################################################
diff --git a/compiler-rt/lib/asan/asan_allocator.cpp b/compiler-rt/lib/asan/asan_allocator.cpp
index f5c273e7fc25..0e9add1ce737 100644
--- a/compiler-rt/lib/asan/asan_allocator.cpp
+++ b/compiler-rt/lib/asan/asan_allocator.cpp
@@ -72,14 +72,14 @@ static const uptr kAllocBegMagic = 0xCC6E96B9;
struct ChunkHeader {
// 1-st 8 bytes.
- atomic_uint8_t chunk_state;
- u32 alloc_tid : 24;
-
- u32 free_tid : 24;
- u32 from_memalign : 1;
- u32 alloc_type : 2;
- u32 rz_log : 3;
- u32 lsan_tag : 2;
+ u32 chunk_state : 8; // Must be first.
+ u32 alloc_tid : 24;
+
+ u32 free_tid : 24;
+ u32 from_memalign : 1;
+ u32 alloc_type : 2;
+ u32 rz_log : 3;
+ u32 lsan_tag : 2;
// 2-nd 8 bytes
// This field is used for small sizes. For large sizes it is equal to
// SizeClassMap::kMaxSize and the actual size is stored in the
@@ -88,7 +88,7 @@ struct ChunkHeader {
// align < 8 -> 0
// else -> log2(min(align, 512)) - 2
u32 user_requested_alignment_log : 3;
- atomic_uint32_t alloc_context_id;
+ u32 alloc_context_id;
};
struct ChunkBase : ChunkHeader {
@@ -101,15 +101,14 @@ static const uptr kChunkHeader2Size = sizeof(ChunkBase) - kChunkHeaderSize;
COMPILER_CHECK(kChunkHeaderSize == 16);
COMPILER_CHECK(kChunkHeader2Size <= 16);
+// Every chunk of memory allocated by this allocator can be in one of 3 states:
+// CHUNK_AVAILABLE: the chunk is in the free list and ready to be allocated.
+// CHUNK_ALLOCATED: the chunk is allocated and not yet freed.
+// CHUNK_QUARANTINE: the chunk was freed and put into quarantine zone.
enum {
- // Either just allocated by underlying allocator, but AsanChunk is not yet
- // ready, or almost returned to undelying allocator and AsanChunk is already
- // meaningless.
- CHUNK_INVALID = 0,
- // The chunk is allocated and not yet freed.
- CHUNK_ALLOCATED = 2,
- // The chunk was freed and put into quarantine zone.
- CHUNK_QUARANTINE = 3,
+ CHUNK_AVAILABLE = 0, // 0 is the default value even if we didn't set it.
+ CHUNK_ALLOCATED = 2,
+ CHUNK_QUARANTINE = 3
};
struct AsanChunk: ChunkBase {
@@ -118,7 +117,7 @@ struct AsanChunk: ChunkBase {
if (user_requested_size != SizeClassMap::kMaxSize)
return user_requested_size;
return *reinterpret_cast<uptr *>(
- get_allocator().GetMetaData(AllocBeg(locked_version)));
+ get_allocator().GetMetaData(AllocBeg(locked_version)));
}
void *AllocBeg(bool locked_version = false) {
if (from_memalign) {
@@ -141,12 +140,8 @@ struct QuarantineCallback {
}
void Recycle(AsanChunk *m) {
- u8 old_chunk_state = CHUNK_QUARANTINE;
- if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
- CHUNK_INVALID, memory_order_acquire)) {
- CHECK_EQ(old_chunk_state, CHUNK_QUARANTINE);
- }
-
+ CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
+ atomic_store((atomic_uint8_t*)m, CHUNK_AVAILABLE, memory_order_relaxed);
CHECK_NE(m->alloc_tid, kInvalidTid);
CHECK_NE(m->free_tid, kInvalidTid);
PoisonShadow(m->Beg(),
@@ -306,25 +301,22 @@ struct Allocator {
// housekeeping chunk, like TransferBatch. Start by assuming the former.
AsanChunk *ac = GetAsanChunk((void *)chunk);
uptr allocated_size = allocator.GetActuallyAllocatedSize((void *)ac);
- if (atomic_load(&ac->chunk_state, memory_order_acquire) ==
- CHUNK_ALLOCATED) {
- uptr beg = ac->Beg();
- uptr end = ac->Beg() + ac->UsedSize(true);
- uptr chunk_end = chunk + allocated_size;
- if (chunk < beg && beg < end && end <= chunk_end) {
- // Looks like a valid AsanChunk in use, poison redzones only.
- PoisonShadow(chunk, beg - chunk, kAsanHeapLeftRedzoneMagic);
- uptr end_aligned_down = RoundDownTo(end, SHADOW_GRANULARITY);
- FastPoisonShadowPartialRightRedzone(
- end_aligned_down, end - end_aligned_down,
- chunk_end - end_aligned_down, kAsanHeapLeftRedzoneMagic);
- return;
- }
+ uptr beg = ac->Beg();
+ uptr end = ac->Beg() + ac->UsedSize(true);
+ uptr chunk_end = chunk + allocated_size;
+ if (chunk < beg && beg < end && end <= chunk_end &&
+ ac->chunk_state == CHUNK_ALLOCATED) {
+ // Looks like a valid AsanChunk in use, poison redzones only.
+ PoisonShadow(chunk, beg - chunk, kAsanHeapLeftRedzoneMagic);
+ uptr end_aligned_down = RoundDownTo(end, SHADOW_GRANULARITY);
+ FastPoisonShadowPartialRightRedzone(
+ end_aligned_down, end - end_aligned_down,
+ chunk_end - end_aligned_down, kAsanHeapLeftRedzoneMagic);
+ } else {
+ // This is either not an AsanChunk or freed or quarantined AsanChunk.
+ // In either case, poison everything.
+ PoisonShadow(chunk, allocated_size, kAsanHeapLeftRedzoneMagic);
}
-
- // This is either not an AsanChunk or freed or quarantined AsanChunk.
- // In either case, poison everything.
- PoisonShadow(chunk, allocated_size, kAsanHeapLeftRedzoneMagic);
}
void ReInitialize(const AllocatorOptions &options) {
@@ -389,17 +381,14 @@ struct Allocator {
AsanChunk *right_chunk) {
// Prefer an allocated chunk over freed chunk and freed chunk
// over available chunk.
- u8 left_state = atomic_load(&left_chunk->chunk_state, memory_order_relaxed);
- u8 right_state =
- atomic_load(&right_chunk->chunk_state, memory_order_relaxed);
- if (left_state != right_state) {
- if (left_state == CHUNK_ALLOCATED)
+ if (left_chunk->chunk_state != right_chunk->chunk_state) {
+ if (left_chunk->chunk_state == CHUNK_ALLOCATED)
return left_chunk;
- if (right_state == CHUNK_ALLOCATED)
+ if (right_chunk->chunk_state == CHUNK_ALLOCATED)
return right_chunk;
- if (left_state == CHUNK_QUARANTINE)
+ if (left_chunk->chunk_state == CHUNK_QUARANTINE)
return left_chunk;
- if (right_state == CHUNK_QUARANTINE)
+ if (right_chunk->chunk_state == CHUNK_QUARANTINE)
return right_chunk;
}
// Same chunk_state: choose based on offset.
@@ -414,10 +403,9 @@ struct Allocator {
bool UpdateAllocationStack(uptr addr, BufferedStackTrace *stack) {
AsanChunk *m = GetAsanChunkByAddr(addr);
if (!m) return false;
- if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
- return false;
+ if (m->chunk_state != CHUNK_ALLOCATED) return false;
if (m->Beg() != addr) return false;
- atomic_store(&m->alloc_context_id, StackDepotPut(*stack),
+ atomic_store((atomic_uint32_t *)&m->alloc_context_id, StackDepotPut(*stack),
memory_order_relaxed);
return true;
}
@@ -519,7 +507,7 @@ struct Allocator {
m->free_tid = kInvalidTid;
m->from_memalign = user_beg != beg_plus_redzone;
if (alloc_beg != chunk_beg) {
- CHECK_LE(alloc_beg + 2 * sizeof(uptr), chunk_beg);
+ CHECK_LE(alloc_beg+ 2 * sizeof(uptr), chunk_beg);
reinterpret_cast<uptr *>(alloc_beg)[0] = kAllocBegMagic;
reinterpret_cast<uptr *>(alloc_beg)[1] = chunk_beg;
}
@@ -536,8 +524,7 @@ struct Allocator {
}
m->user_requested_alignment_log = user_requested_alignment_log;
- atomic_store(&m->alloc_context_id, StackDepotPut(*stack),
- memory_order_relaxed);
+ m->alloc_context_id = StackDepotPut(*stack);
uptr size_rounded_down_to_granularity =
RoundDownTo(size, SHADOW_GRANULARITY);
@@ -570,7 +557,7 @@ struct Allocator {
: __lsan::kDirectlyLeaked;
#endif
// Must be the last mutation of metadata in this function.
- atomic_store(&m->chunk_state, CHUNK_ALLOCATED, memory_order_release);
+ atomic_store((atomic_uint8_t *)m, CHUNK_ALLOCATED, memory_order_release);
ASAN_MALLOC_HOOK(res, size);
return res;
}
@@ -578,10 +565,10 @@ struct Allocator {
// Set quarantine flag if chunk is allocated, issue ASan error report on
// available and quarantined chunks. Return true on success, false otherwise.
bool AtomicallySetQuarantineFlagIfAllocated(AsanChunk *m, void *ptr,
- BufferedStackTrace *stack) {
+ BufferedStackTrace *stack) {
u8 old_chunk_state = CHUNK_ALLOCATED;
// Flip the chunk_state atomically to avoid race on double-free.
- if (!atomic_compare_exchange_strong(&m->chunk_state, &old_chunk_state,
+ if (!atomic_compare_exchange_strong((atomic_uint8_t *)m, &old_chunk_state,
CHUNK_QUARANTINE,
memory_order_acquire)) {
ReportInvalidFree(ptr, old_chunk_state, stack);
@@ -595,8 +582,7 @@ struct Allocator {
// Expects the chunk to already be marked as quarantined by using
// AtomicallySetQuarantineFlagIfAllocated.
void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack) {
- CHECK_EQ(atomic_load(&m->chunk_state, memory_order_relaxed),
- CHUNK_QUARANTINE);
+ CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
CHECK_GE(m->alloc_tid, 0);
if (SANITIZER_WORDSIZE == 64) // On 32-bits this resides in user area.
CHECK_EQ(m->free_tid, kInvalidTid);
@@ -691,7 +677,7 @@ struct Allocator {
void *new_ptr = Allocate(new_size, 8, stack, FROM_MALLOC, true);
if (new_ptr) {
- u8 chunk_state = atomic_load(&m->chunk_state, memory_order_acquire);
+ u8 chunk_state = m->chunk_state;
if (chunk_state != CHUNK_ALLOCATED)
ReportInvalidFree(old_ptr, chunk_state, stack);
CHECK_NE(REAL(memcpy), nullptr);
@@ -735,8 +721,7 @@ struct Allocator {
// Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
AsanChunk *GetAsanChunk(void *alloc_beg) {
- if (!alloc_beg)
- return nullptr;
+ if (!alloc_beg) return nullptr;
if (!allocator.FromPrimary(alloc_beg)) {
uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]);
@@ -752,13 +737,11 @@ struct Allocator {
}
AsanChunk *GetAsanChunkDebug(void *alloc_beg) {
- if (!alloc_beg)
- return nullptr;
+ if (!alloc_beg) return nullptr;
if (!allocator.FromPrimary(alloc_beg)) {
uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]);
- Printf("GetAsanChunkDebug1 alloc_beg %p meta %p m %p\n", alloc_beg, meta,
- m);
+ Printf("GetAsanChunkDebug1 alloc_beg %p meta %p m %p\n", alloc_beg, meta, m);
return m;
}
uptr *alloc_magic = reinterpret_cast<uptr *>(alloc_beg);
@@ -771,6 +754,7 @@ struct Allocator {
return reinterpret_cast<AsanChunk *>(alloc_beg);
}
+
AsanChunk *GetAsanChunkByAddr(uptr p) {
void *alloc_beg = allocator.GetBlockBegin(reinterpret_cast<void *>(p));
return GetAsanChunk(alloc_beg);
@@ -786,16 +770,14 @@ struct Allocator {
AsanChunk *GetAsanChunkByAddrFastLockedDebug(uptr p) {
void *alloc_beg =
allocator.GetBlockBeginFastLockedDebug(reinterpret_cast<void *>(p));
- Printf("GetAsanChunkByAddrFastLockedDebug p %p alloc_beg %p\n", p,
- alloc_beg);
+ Printf("GetAsanChunkByAddrFastLockedDebug p %p alloc_beg %p\n", p, alloc_beg);
return GetAsanChunkDebug(alloc_beg);
}
uptr AllocationSize(uptr p) {
AsanChunk *m = GetAsanChunkByAddr(p);
if (!m) return 0;
- if (atomic_load(&m->chunk_state, memory_order_acquire) != CHUNK_ALLOCATED)
- return 0;
+ if (m->chunk_state != CHUNK_ALLOCATED) return 0;
if (m->Beg() != p) return 0;
return m->UsedSize();
}
@@ -861,16 +843,13 @@ static AsanAllocator &get_allocator() {
}
bool AsanChunkView::IsValid() const {
- return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) !=
- CHUNK_INVALID;
+ return chunk_ && chunk_->chunk_state != CHUNK_AVAILABLE;
}
bool AsanChunkView::IsAllocated() const {
- return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
- CHUNK_ALLOCATED;
+ return chunk_ && chunk_->chunk_state == CHUNK_ALLOCATED;
}
bool AsanChunkView::IsQuarantined() const {
- return chunk_ && atomic_load(&chunk_->chunk_state, memory_order_relaxed) ==
- CHUNK_QUARANTINE;
+ return chunk_ && chunk_->chunk_state == CHUNK_QUARANTINE;
}
uptr AsanChunkView::Beg() const { return chunk_->Beg(); }
uptr AsanChunkView::End() const { return Beg() + UsedSize(); }
@@ -891,9 +870,7 @@ static StackTrace GetStackTraceFromId(u32 id) {
return res;
}
-u32 AsanChunkView::GetAllocStackId() const {
- return atomic_load(&chunk_->alloc_context_id, memory_order_relaxed);
-}
+u32 AsanChunkView::GetAllocStackId() const { return chunk_->alloc_context_id; }
u32 AsanChunkView::GetFreeStackId() const { return chunk_->free_context_id; }
StackTrace AsanChunkView::GetAllocStack() const {
@@ -1058,7 +1035,7 @@ void AsanSoftRssLimitExceededCallback(bool limit_exceeded) {
instance.SetRssLimitExceeded(limit_exceeded);
}
-} // namespace __asan
+} // namespace __asan
// --- Implementation of LSan-specific functions --- {{{1
namespace __lsan {
@@ -1078,10 +1055,10 @@ void GetAllocatorGlobalRange(uptr *begin, uptr *end) {
uptr PointsIntoChunk(void* p) {
uptr addr = reinterpret_cast<uptr>(p);
__asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(addr);
- if (!m || atomic_load(&m->chunk_state, memory_order_acquire) !=
- __asan::CHUNK_ALLOCATED)
- return 0;
+ if (!m) return 0;
uptr chunk = m->Beg();
+ if (m->chunk_state != __asan::CHUNK_ALLOCATED)
+ return 0;
if (m->AddrIsInside(addr, /*locked_version=*/true))
return chunk;
if (IsSpecialCaseOfOperatorNew0(chunk, m->UsedSize(/*locked_version*/ true),
@@ -1095,8 +1072,7 @@ extern "C" SANITIZER_WEAK_ATTRIBUTE const char *__lsan_current_stage;
void GetUserBeginDebug(uptr chunk) {
Printf("GetUserBeginDebug1 chunk %p\n", chunk);
- __asan::AsanChunk *m =
- __asan::instance.GetAsanChunkByAddrFastLockedDebug(chunk);
+ __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLockedDebug(chunk);
Printf("GetUserBeginDebug2 m %p\n", m);
}
@@ -1123,8 +1099,7 @@ LsanMetadata::LsanMetadata(uptr chunk) {
bool LsanMetadata::allocated() const {
__asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
- return atomic_load(&m->chunk_state, memory_order_relaxed) ==
- __asan::CHUNK_ALLOCATED;
+ return m->chunk_state == __asan::CHUNK_ALLOCATED;
}
ChunkTag LsanMetadata::tag() const {
@@ -1144,7 +1119,7 @@ uptr LsanMetadata::requested_size() const {
u32 LsanMetadata::stack_trace_id() const {
__asan::AsanChunk *m = reinterpret_cast<__asan::AsanChunk *>(metadata_);
- return atomic_load(&m->alloc_context_id, memory_order_relaxed);
+ return m->alloc_context_id;
}
void ForEachChunk(ForEachChunkCallback callback, void *arg) {
@@ -1155,9 +1130,7 @@ IgnoreObjectResult IgnoreObjectLocked(const void *p) {
uptr addr = reinterpret_cast<uptr>(p);
__asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddr(addr);
if (!m) return kIgnoreObjectInvalid;
- if ((atomic_load(&m->chunk_state, memory_order_acquire) ==
- __asan::CHUNK_ALLOCATED) &&
- m->AddrIsInside(addr)) {
+ if ((m->chunk_state == __asan::CHUNK_ALLOCATED) && m->AddrIsInside(addr)) {
if (m->lsan_tag == kIgnored)
return kIgnoreObjectAlreadyIgnored;
m->lsan_tag = __lsan::kIgnored;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
index 0cf483da1e5c..6d73784d77d0 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
@@ -148,6 +148,7 @@ class CombinedAllocator {
return secondary_.GetBlockBeginFastLocked(p);
}
+
uptr GetActuallyAllocatedSize(void *p) {
if (primary_.PointerIsMine(p))
return primary_.GetActuallyAllocatedSize(p);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
index a6126fc6265e..7af469c56fd6 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
@@ -203,8 +203,7 @@ class SizeClassAllocator64 {
uptr class_id = GetSizeClass(p);
uptr size = ClassIdToSize(class_id);
Printf("GetBlockBeginDebug1 p %p class_id %p size %p\n", p, class_id, size);
- if (!size)
- return nullptr;
+ if (!size) return nullptr;
uptr chunk_idx = GetChunkIdx((uptr)p, size);
uptr reg_beg = GetRegionBegin(p);
uptr beg = chunk_idx * size;
@@ -213,16 +212,16 @@ class SizeClassAllocator64 {
"GetBlockBeginDebug2 chunk_idx %p reg_beg %p beg %p next_beg %p "
"kNumClasses %p\n",
chunk_idx, reg_beg, beg, next_beg, kNumClasses);
- if (class_id >= kNumClasses)
- return nullptr;
+ if (class_id >= kNumClasses) return nullptr;
const RegionInfo *region = AddressSpaceView::Load(GetRegionInfo(class_id));
Printf("GetBlockBeginDebug3 region %p region->mapped_user %p\n", region,
region->mapped_user);
if (region->mapped_user >= next_beg)
- return reinterpret_cast<void *>(reg_beg + beg);
+ return reinterpret_cast<void*>(reg_beg + beg);
return nullptr;
}
+
uptr GetActuallyAllocatedSize(void *p) {
CHECK(PointerIsMine(p));
return ClassIdToSize(GetSizeClass(p));
More information about the llvm-commits
mailing list