[libc-commits] [libc] [libc] Implement dual freestore rotation for baremetal heap (PR #209811)

[Schrodinger ZHU Yifan via libc-commits]

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@@ -189,6 +189,12 @@
       "doc": "Trap with SIGFPE when feraiseexcept is called with unmasked floating point exceptions, similar to glibc's behavior.  This is currently working only on x86 with SSE."
     }
   },
+  "baremetal": {
+    "LIBC_COPT_BAREMETAL_HEAP_ENABLE_FREESTORE_ROTATION": {
+      "value": true,
+      "doc": "Enable rotational dual freestore in FreeListHeap to delay reuse of freed memory. This, when combined with sanitizers, helps detect Use-After-Free (UAF) bugs more reliably by preventing rapid reallocation of recently freed blocks."
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SchrodingerZhu wrote:

> Is there any user benefit for this change today? 

Yes, in quarantined mode, the checks are more likely to be triggered 

https://github.com/llvm/llvm-project/pull/209811