ASAN activate/deactive controls thread_local_quarantine_size_kb option.

Summary:
Bypass quarantine altogether when quarantine size is set ot zero.
Also, relax atomic load/store of quarantine parameters, the
release/acquire semantics is an overkill here.

Reviewers: eugenis

Subscribers: kubabrecka, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D28586

llvm-svn: 291791

compiler-rt/lib/asan/asan_activation.cc

@@ -77,12 +77,13 @@ static struct AsanDeactivatedFlags {
 
   void Print() {
     Report(
-        "quarantine_size_mb %d, max_redzone %d, poison_heap %d, "
-        "malloc_context_size %d, alloc_dealloc_mismatch %d, "
-        "allocator_may_return_null %d, coverage %d, coverage_dir %s, "
-        "allocator_release_to_os_interval_ms %d\n",
-        allocator_options.quarantine_size_mb, allocator_options.max_redzone,
-        poison_heap, malloc_context_size,
+        "quarantine_size_mb %d, thread_local_quarantine_size_kb %d, "
+        "max_redzone %d, poison_heap %d, malloc_context_size %d, "
+        "alloc_dealloc_mismatch %d, allocator_may_return_null %d, coverage %d, "
+        "coverage_dir %s, allocator_release_to_os_interval_ms %d\n",
+        allocator_options.quarantine_size_mb,
+        allocator_options.thread_local_quarantine_size_kb,
+        allocator_options.max_redzone, poison_heap, malloc_context_size,
         allocator_options.alloc_dealloc_mismatch,
         allocator_options.may_return_null, coverage, coverage_dir,
         allocator_options.release_to_os_interval_ms);
@@ -109,6 +110,7 @@ void AsanDeactivate() {
 
   AllocatorOptions disabled = asan_deactivated_flags.allocator_options;
   disabled.quarantine_size_mb = 0;
+  disabled.thread_local_quarantine_size_kb = 0;
   disabled.min_redzone = 16;  // Redzone must be at least 16 bytes long.
   disabled.max_redzone = 16;
   disabled.alloc_dealloc_mismatch = false;

compiler-rt/lib/asan/asan_activation_flags.inc

@@ -24,6 +24,7 @@
 ASAN_ACTIVATION_FLAG(int, redzone)
 ASAN_ACTIVATION_FLAG(int, max_redzone)
 ASAN_ACTIVATION_FLAG(int, quarantine_size_mb)
+ASAN_ACTIVATION_FLAG(int, thread_local_quarantine_size_kb)
 ASAN_ACTIVATION_FLAG(bool, alloc_dealloc_mismatch)
 ASAN_ACTIVATION_FLAG(bool, poison_heap)
 

compiler-rt/lib/asan/asan_flags.cc

@@ -169,6 +169,11 @@ void InitializeFlags() {
         (ASAN_LOW_MEMORY) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10);
     f->thread_local_quarantine_size_kb = kDefaultThreadLocalQuarantineSizeKb;
   }
+  if (f->thread_local_quarantine_size_kb == 0 && f->quarantine_size_mb > 0) {
+    Report("%s: thread_local_quarantine_size_kb can be set to 0 only when "
+           "quarantine_size_mb is set to 0\n", SanitizerToolName);
+    Die();
+  }
   if (!f->replace_str && common_flags()->intercept_strlen) {
     Report("WARNING: strlen interceptor is enabled even though replace_str=0. "
            "Use intercept_strlen=0 to disable it.");

compiler-rt/lib/sanitizer_common/sanitizer_quarantine.h

@@ -49,18 +49,31 @@ class Quarantine {
   }
 
   void Init(uptr size, uptr cache_size) {
-    atomic_store(&max_size_, size, memory_order_release);
+    // Thread local quarantine size can be zero only when global quarantine size
+    // is zero (it allows us to perform just one atomic read per Put() call).
+    CHECK((size == 0 && cache_size == 0) || cache_size != 0);
+
+    atomic_store(&max_size_, size, memory_order_relaxed);
     atomic_store(&min_size_, size / 10 * 9,
-                 memory_order_release); // 90% of max size.
-    max_cache_size_ = cache_size;
+                 memory_order_relaxed);  // 90% of max size.
+    atomic_store(&max_cache_size_, cache_size, memory_order_relaxed);
   }
 
-  uptr GetSize() const { return atomic_load(&max_size_, memory_order_acquire); }
-  uptr GetCacheSize() const { return max_cache_size_; }
+  uptr GetSize() const { return atomic_load(&max_size_, memory_order_relaxed); }
+  uptr GetCacheSize() const {
+    return atomic_load(&max_cache_size_, memory_order_relaxed);
+  }
 
   void Put(Cache *c, Callback cb, Node *ptr, uptr size) {
+    uptr cache_size = GetCacheSize();
+    if (cache_size) {
       c->Enqueue(cb, ptr, size);
-    if (c->Size() > max_cache_size_)
+    } else {
+      // cache_size == 0 only when size == 0 (see Init).
+      cb.Recycle(ptr);
+    }
+    // Check cache size anyway to accommodate for runtime cache_size change.
+    if (c->Size() > cache_size)
       Drain(c, cb);
   }
 
@@ -83,7 +96,7 @@ class Quarantine {
   char pad0_[kCacheLineSize];
   atomic_uintptr_t max_size_;
   atomic_uintptr_t min_size_;
-  uptr max_cache_size_;
+  atomic_uintptr_t max_cache_size_;
   char pad1_[kCacheLineSize];
   SpinMutex cache_mutex_;
   SpinMutex recycle_mutex_;
@@ -92,7 +105,7 @@ class Quarantine {
 
   void NOINLINE Recycle(Callback cb) {
     Cache tmp;
-    uptr min_size = atomic_load(&min_size_, memory_order_acquire);
+    uptr min_size = atomic_load(&min_size_, memory_order_relaxed);
     {
       SpinMutexLock l(&cache_mutex_);
       while (cache_.Size() > min_size) {
@@ -205,6 +218,7 @@ class QuarantineCache {
     return b;
   }
 };
+
 } // namespace __sanitizer
 
 #endif // SANITIZER_QUARANTINE_H

compiler-rt/test/asan/TestCases/Linux/thread_local_quarantine_size_kb.cc

@@ -5,8 +5,10 @@
 // RUN:   FileCheck %s --check-prefix=CHECK-VALUE
 // RUN: %env_asan_opts=thread_local_quarantine_size_kb=64:quarantine_size_mb=64 %run %t 2>&1 | \
 // RUN:   FileCheck %s --allow-empty --check-prefix=CHECK-SMALL-LOCAL-CACHE-SMALL-OVERHEAD
-// RUN: %env_asan_opts=thread_local_quarantine_size_kb=0:quarantine_size_mb=64 %run %t 2>&1 | \
-// RUN:   FileCheck %s --check-prefix=CHECK-NO-LOCAL-CACHE-HUGE-OVERHEAD
+// RUN: %env_asan_opts=thread_local_quarantine_size_kb=0:quarantine_size_mb=0 %run %t 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CHECK-QUARANTINE-DISABLED
+// RUN: %env_asan_opts=thread_local_quarantine_size_kb=0:quarantine_size_mb=64 not %run %t 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CHECK-FOR-PARAMETER-ERROR
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -37,4 +39,5 @@ int main() {
 
 // CHECK-VALUE: thread_local_quarantine_size_kb=256K
 // CHECK-SMALL-LOCAL-CACHE-SMALL-OVERHEAD-NOT: Heap size limit exceeded
-// CHECK-NO-LOCAL-CACHE-HUGE-OVERHEAD: Heap size limit exceeded
+// CHECK-QUARANTINE-DISABLED-NOT: Heap size limit exceeded
+// CHECK-FOR-PARAMETER-ERROR: thread_local_quarantine_size_kb can be set to 0 only when quarantine_size_mb is set to 0