[compiler-rt] 47bd46e - allocation_ring_buffer_size to 0 disables stack collection

[Florian Mayer via llvm-commits]

Author: Florian Mayer
Date: 2023-01-13T09:56:12-08:00
New Revision: 47bd46e20c7ede9268cbcd9401816619b2197bcc

URL: https://github.com/llvm/llvm-project/commit/47bd46e20c7ede9268cbcd9401816619b2197bcc
DIFF: https://github.com/llvm/llvm-project/commit/47bd46e20c7ede9268cbcd9401816619b2197bcc.diff

LOG: allocation_ring_buffer_size to 0 disables stack collection

Reviewed By: hctim, eugenis

Differential Revision: https://reviews.llvm.org/D141631

Added: 
    

Modified: 
    compiler-rt/lib/scudo/standalone/combined.h

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
index 37d94e39eeb7..da8104cca7e5 100644
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -901,6 +901,10 @@ class Allocator {
 
   void setTrackAllocationStacks(bool Track) {
     initThreadMaybe();
+    if (getFlags()->allocation_ring_buffer_size == 0) {
+      DCHECK(!Primary.Options.get(OptionsBit::TrackAllocationStacks));
+      return;
+    }
     if (Track)
       Primary.Options.set(OptionBit::TrackAllocationStacks);
     else
@@ -939,7 +943,8 @@ class Allocator {
 
   uptr getRingBufferSize() {
     initThreadMaybe();
-    return ringBufferSizeInBytes(getRingBuffer()->Size);
+    auto *RingBuffer = getRingBuffer();
+    return RingBuffer ? ringBufferSizeInBytes(RingBuffer->Size) : 0;
   }
 
   static bool setRingBufferSizeForBuffer(char *Buffer, size_t Size) {
@@ -1406,8 +1411,8 @@ class Allocator {
                                      const char *RingBufferPtr) {
     auto *RingBuffer =
         reinterpret_cast<const AllocationRingBuffer *>(RingBufferPtr);
-    if (!RingBuffer)
-      return; //  just in case; called before init
+    if (!RingBuffer || RingBuffer->Size == 0)
+      return;
     uptr Pos = atomic_load_relaxed(&RingBuffer->Pos);
 
     for (uptr I = Pos - 1;
@@ -1493,9 +1498,8 @@ class Allocator {
   void initRingBuffer() {
     u32 AllocationRingBufferSize =
         static_cast<u32>(getFlags()->allocation_ring_buffer_size);
-    // Have at least one entry so we don't need to special case.
     if (AllocationRingBufferSize < 1)
-      AllocationRingBufferSize = 1;
+      return;
     MapPlatformData Data = {};
     RawRingBuffer = static_cast<char *>(
         map(/*Addr=*/nullptr,