1 files changed, 20 insertions, 1 deletions

diff --git a/libbb/const_hack.c b/libbb/const_hack.c
index 9575e6d67..1d175481b 100644
--- a/libbb/const_hack.c
+++ b/libbb/const_hack.c
@@ -9,8 +9,27 @@
 #include "libbb.h"
 
 #if defined(__clang_major__) && __clang_major__ >= 9
+/* Clang/llvm drops assignment to "constant" storage. Silently.
+ * Needs serious convincing to not eliminate the store.
+ */
+static ALWAYS_INLINE void* not_const_pp(const void *p)
+{
+        void *pp;
+        asm volatile (
+                "# forget that p points to const"
+                : /*outputs*/ "=r" (pp)
+                : /*inputs*/ "0" (p)
+        );
+        return pp;
+}
+void FAST_FUNC ASSIGN_CONST_PTR(const void *pptr, void *v)
+{
+        *(void**)not_const_pp(pptr) = v;
+        barrier();
+}
 void FAST_FUNC XZALLOC_CONST_PTR(const void *pptr, size_t size)
 {
-        ASSIGN_CONST_PTR(pptr, xzalloc(size));
+        *(void**)not_const_pp(pptr) = xzalloc(size);
+        barrier();
 }
 #endif