[compiler-rt] a66dc46 - [scudo] allocation_ring_buffer_size <= 0 disables buffer (#71791)

[via llvm-commits]

Author: Florian Mayer
Date: 2023-11-14T14:58:05-08:00
New Revision: a66dc461ace46e9edc8364c077d68f910b1d8ce5

URL: https://github.com/llvm/llvm-project/commit/a66dc461ace46e9edc8364c077d68f910b1d8ce5
DIFF: https://github.com/llvm/llvm-project/commit/a66dc461ace46e9edc8364c077d68f910b1d8ce5.diff

LOG: [scudo] allocation_ring_buffer_size <= 0 disables buffer (#71791)

Prevent a null pointer exception for allocation_ring_buffer_size < 0.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
index b1700e5ecef7f5b..25c597199a65825 100644
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -886,7 +886,7 @@ class Allocator {
 
   void setTrackAllocationStacks(bool Track) {
     initThreadMaybe();
-    if (getFlags()->allocation_ring_buffer_size == 0) {
+    if (getFlags()->allocation_ring_buffer_size <= 0) {
       DCHECK(!Primary.Options.load().get(OptionBit::TrackAllocationStacks));
       return;
     }
@@ -1490,10 +1490,10 @@ class Allocator {
   }
 
   void mapAndInitializeRingBuffer() {
+    if (getFlags()->allocation_ring_buffer_size <= 0)
+      return;
     u32 AllocationRingBufferSize =
         static_cast<u32>(getFlags()->allocation_ring_buffer_size);
-    if (AllocationRingBufferSize < 1)
-      return;
     MemMapT MemMap;
     MemMap.map(
         /*Addr=*/0U,

diff  --git a/compiler-rt/lib/scudo/standalone/flags.inc b/compiler-rt/lib/scudo/standalone/flags.inc
index 60aeb1f1df570ac..f5a2bab5057ae13 100644
--- a/compiler-rt/lib/scudo/standalone/flags.inc
+++ b/compiler-rt/lib/scudo/standalone/flags.inc
@@ -47,4 +47,5 @@ SCUDO_FLAG(int, release_to_os_interval_ms, SCUDO_ANDROID ? INT32_MIN : 5000,
            "memory to the OS. Negative values disable the feature.")
 
 SCUDO_FLAG(int, allocation_ring_buffer_size, 32768,
-           "Entries to keep in the allocation ring buffer for scudo.")
+           "Entries to keep in the allocation ring buffer for scudo. "
+           "Values less or equal to zero disable the buffer.")