Initialize big object header properly (#269)

kpamnany · web-flow · commit 2aa915d7ff17 · 2025-12-11T20:09:50.000-05:00
Prevent uninitialized memory from causing an assertion failure.
diff --git a/src/gc.c b/src/gc.c
@@ -1014,6 +1014,7 @@ STATIC_INLINE jl_value_t *jl_gc_big_alloc_inner(jl_ptls_t ptls, size_t sz)
     memset(v, 0xee, allocsz);
 #endif
     v->sz = allocsz;
+    v->header = 0;
     gc_big_object_link(ptls->gc_tls.heap.young_generation_of_bigvals, v);
     return jl_valueof(&v->header);
 }

Original file line number	Diff line number	Diff line change
`@@ -1014,6 +1014,7 @@ STATIC_INLINE jl_value_t *jl_gc_big_alloc_inner(jl_ptls_t ptls, size_t sz)`
`1014`	`1014`	`memset(v, 0xee, allocsz);`
`1015`	`1015`	`#endif`
`1016`	`1016`	`v->sz = allocsz;`
	`1017`	`+ v->header = 0;`
`1017`	`1018`	`gc_big_object_link(ptls->gc_tls.heap.young_generation_of_bigvals, v);`
`1018`	`1019`	`return jl_valueof(&v->header);`
`1019`	`1020`	`}`