[compiler-rt] 94a391b - [scudo] Calling iterateOverChunks requires holding lock

[Chia-hung Duan via llvm-commits]

Author: Chia-hung Duan
Date: 2023-02-15T23:44:44Z
New Revision: 94a391b94972b68db03320f27ebf2e279051b3e6

URL: https://github.com/llvm/llvm-project/commit/94a391b94972b68db03320f27ebf2e279051b3e6
DIFF: https://github.com/llvm/llvm-project/commit/94a391b94972b68db03320f27ebf2e279051b3e6.diff

LOG: [scudo] Calling iterateOverChunks requires holding lock

Ensure the allocator is disabled before visiting all chunks.

Reviewed By: cferris

Differential Revision: https://reviews.llvm.org/D142157

Added: 
    

Modified: 
    compiler-rt/lib/scudo/standalone/primary32.h
    compiler-rt/lib/scudo/standalone/primary64.h
    compiler-rt/lib/scudo/standalone/secondary.h
    compiler-rt/lib/scudo/standalone/wrappers_c.inc

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/scudo/standalone/primary32.h b/compiler-rt/lib/scudo/standalone/primary32.h
index 544f0ee98797..2a204ca40f96 100644
--- a/compiler-rt/lib/scudo/standalone/primary32.h
+++ b/compiler-rt/lib/scudo/standalone/primary32.h
@@ -204,11 +204,14 @@ template <typename Config> class SizeClassAllocator32 {
     }
   }
 
-  template <typename F>
-  void iterateOverBlocks(F Callback) NO_THREAD_SAFETY_ANALYSIS {
+  template <typename F> void iterateOverBlocks(F Callback) {
     uptr MinRegionIndex = NumRegions, MaxRegionIndex = 0;
     for (uptr I = 0; I < NumClasses; I++) {
       SizeClassInfo *Sci = getSizeClassInfo(I);
+      // TODO: The call of `iterateOverBlocks` requires disabling
+      // SizeClassAllocator32. We may consider locking each region on demand
+      // only.
+      Sci->Mutex.assertHeld();
       if (Sci->MinRegionIndex < MinRegionIndex)
         MinRegionIndex = Sci->MinRegionIndex;
       if (Sci->MaxRegionIndex > MaxRegionIndex)

diff  --git a/compiler-rt/lib/scudo/standalone/primary64.h b/compiler-rt/lib/scudo/standalone/primary64.h
index 1c9c6159f19b..3c53c03a6d19 100644
--- a/compiler-rt/lib/scudo/standalone/primary64.h
+++ b/compiler-rt/lib/scudo/standalone/primary64.h
@@ -226,12 +226,15 @@ template <typename Config> class SizeClassAllocator64 {
     }
   }
 
-  template <typename F>
-  void iterateOverBlocks(F Callback) NO_THREAD_SAFETY_ANALYSIS {
+  template <typename F> void iterateOverBlocks(F Callback) {
     for (uptr I = 0; I < NumClasses; I++) {
       if (I == SizeClassMap::BatchClassId)
         continue;
       RegionInfo *Region = getRegionInfo(I);
+      // TODO: The call of `iterateOverBlocks` requires disabling
+      // SizeClassAllocator64. We may consider locking each region on demand
+      // only.
+      Region->Mutex.assertHeld();
       const uptr BlockSize = getSizeByClassId(I);
       const uptr From = Region->RegionBeg;
       const uptr To = From + Region->AllocatedUser;

diff  --git a/compiler-rt/lib/scudo/standalone/secondary.h b/compiler-rt/lib/scudo/standalone/secondary.h
index e98e02094167..3a11c4778862 100644
--- a/compiler-rt/lib/scudo/standalone/secondary.h
+++ b/compiler-rt/lib/scudo/standalone/secondary.h
@@ -456,8 +456,9 @@ template <typename Config> class MapAllocator {
     Mutex.unlock();
   }
 
-  template <typename F>
-  void iterateOverBlocks(F Callback) const NO_THREAD_SAFETY_ANALYSIS {
+  template <typename F> void iterateOverBlocks(F Callback) const {
+    Mutex.assertHeld();
+
     for (const auto &H : InUseBlocks) {
       uptr Ptr = reinterpret_cast<uptr>(&H) + LargeBlock::getHeaderSize();
       if (allocatorSupportsMemoryTagging<Config>())

diff  --git a/compiler-rt/lib/scudo/standalone/wrappers_c.inc b/compiler-rt/lib/scudo/standalone/wrappers_c.inc
index bbe3617dd0d6..6c4f10d2d898 100644
--- a/compiler-rt/lib/scudo/standalone/wrappers_c.inc
+++ b/compiler-rt/lib/scudo/standalone/wrappers_c.inc
@@ -238,7 +238,10 @@ INTERFACE WEAK int SCUDO_PREFIX(malloc_info)(UNUSED int options, FILE *stream) {
     if (size < max_size)
       sizes[size]++;
   };
+
+  SCUDO_ALLOCATOR.disable();
   SCUDO_ALLOCATOR.iterateOverChunks(0, -1ul, callback, sizes);
+  SCUDO_ALLOCATOR.enable();
 
   fputs("<malloc version=\"scudo-1\">\n", stream);
   for (scudo::uptr i = 0; i != max_size; ++i)