Merge pull request #224 from michael-denyer/fix-kv-alloc-double-free

glm: fix kv_alloc double-free on KV re-allocation (stale pre-Metal free block)

c/tests/test_kv_alloc.c

@@ -0,0 +1,23 @@
+/* kv_alloc must survive re-allocation on the same KVState: every free path is
+ * guarded by if(k->Lc) precisely so callers (context resize, slot re-init) can
+ * call it again. A stale duplicate free block frees every Lc[i]/Rc[i] and both
+ * arrays twice on the second call -> allocator abort. No model file needed:
+ * the CPU path of kv_alloc only reads c->n_layers/kv_lora/qk_rope. */
+#define main coli_glm_main_unused
+#include "../glm.c"
+#undef main
+
+int main(void){
+    static Model m;
+    m.c.n_layers=2; m.c.kv_lora=8; m.c.qk_rope=4;
+    m.kv=calloc(1,sizeof(KVState));
+    kv_alloc(&m,16);
+    for(int i=0;i<m.c.n_layers+1;i++){ m.Lc[i][0]=1.0f; m.Rc[i][0]=1.0f; }
+    kv_alloc(&m,32);                       /* the re-allocation path under test */
+    for(int i=0;i<m.c.n_layers+1;i++){
+        m.Lc[i][(int64_t)32*m.c.kv_lora-1]=2.0f;
+        m.Rc[i][(int64_t)32*m.c.qk_rope-1]=2.0f;
+    }
+    printf("OK kv_alloc re-allocation\n");
+    return 0;
+}