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, 32 insertions, 0 deletions

diff --git a/drivers/s390/char/ctrlchar.h b/drivers/s390/char/ctrlchar.h
new file mode 100644
index 000000000..e52afa3b8
--- /dev/null
+++ b/drivers/s390/char/ctrlchar.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Unified handling of special chars.
+ *
+ *    Copyright IBM Corp. 2001
+ *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
+ *
+ */
+
+#include <linux/tty.h>
+#include <linux/sysrq.h>
+#include <linux/workqueue.h>
+
+extern unsigned int
+ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty);
+
+
+#define CTRLCHAR_NONE  (1 << 8)
+#define CTRLCHAR_CTRL  (2 << 8)
+#define CTRLCHAR_SYSRQ (3 << 8)
+
+#define CTRLCHAR_MASK (~0xffu)
+
+
+#ifdef CONFIG_MAGIC_SYSRQ
+struct sysrq_work {
+	int key;
+	struct work_struct work;
+};
+
+void schedule_sysrq_work(struct sysrq_work *sw);
+#endif