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, 24 insertions, 0 deletions

diff --git a/fs/proc/cmdline.c b/fs/proc/cmdline.c
new file mode 100644
index 000000000..a6f761219
--- /dev/null
+++ b/fs/proc/cmdline.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include "internal.h"
+
+static int cmdline_proc_show(struct seq_file *m, void *v)
+{
+	seq_puts(m, saved_command_line);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static int __init proc_cmdline_init(void)
+{
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("cmdline", 0, NULL, cmdline_proc_show);
+	pde_make_permanent(pde);
+	pde->size = saved_command_line_len + 1;
+	return 0;
+}
+fs_initcall(proc_cmdline_init);