selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/include/trace/events/initcall.h b/include/trace/events/initcall.h
new file mode 100644
index 000000000..5282afdf3
--- /dev/null
+++ b/include/trace/events/initcall.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM initcall
+
+#if !defined(_TRACE_INITCALL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_INITCALL_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(initcall_level,
+
+	TP_PROTO(const char *level),
+
+	TP_ARGS(level),
+
+	TP_STRUCT__entry(
+		__string(level, level)
+	),
+
+	TP_fast_assign(
+		__assign_str(level);
+	),
+
+	TP_printk("level=%s", __get_str(level))
+);
+
+TRACE_EVENT(initcall_start,
+
+	TP_PROTO(initcall_t func),
+
+	TP_ARGS(func),
+
+	TP_STRUCT__entry(
+		/*
+		 * Use field_struct to avoid is_signed_type()
+		 * comparison of a function pointer
+		 */
+		__field_struct(initcall_t, func)
+	),
+
+	TP_fast_assign(
+		__entry->func = func;
+	),
+
+	TP_printk("func=%pS", __entry->func)
+);
+
+TRACE_EVENT(initcall_finish,
+
+	TP_PROTO(initcall_t func, int ret),
+
+	TP_ARGS(func, ret),
+
+	TP_STRUCT__entry(
+		/*
+		 * Use field_struct to avoid is_signed_type()
+		 * comparison of a function pointer
+		 */
+		__field_struct(initcall_t,	func)
+		__field(int,			ret)
+	),
+
+	TP_fast_assign(
+		__entry->func = func;
+		__entry->ret = ret;
+	),
+
+	TP_printk("func=%pS ret=%d", __entry->func, __entry->ret)
+);
+
+#endif /* if !defined(_TRACE_GPIO_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>