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, 54 insertions, 0 deletions

diff --git a/init/version.c b/init/version.c
new file mode 100644
index 000000000..94c96f6fb
--- /dev/null
+++ b/init/version.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/init/version.c
+ *
+ *  Copyright (C) 1992  Theodore Ts'o
+ *
+ *  May be freely distributed as part of Linux.
+ */
+
+#include <generated/compile.h>
+#include <linux/build-salt.h>
+#include <linux/elfnote-lto.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+#include <linux/proc_ns.h>
+
+static int __init early_hostname(char *arg)
+{
+	size_t bufsize = sizeof(init_uts_ns.name.nodename);
+	size_t maxlen  = bufsize - 1;
+	ssize_t arglen;
+
+	arglen = strscpy(init_uts_ns.name.nodename, arg, bufsize);
+	if (arglen < 0) {
+		pr_warn("hostname parameter exceeds %zd characters and will be truncated",
+			maxlen);
+	}
+	return 0;
+}
+early_param("hostname", early_hostname);
+
+const char linux_proc_banner[] =
+	"%s version %s"
+	" (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
+	" (" LINUX_COMPILER ") %s\n";
+
+BUILD_SALT;
+BUILD_LTO_INFO;
+
+/*
+ * init_uts_ns and linux_banner contain the build version and timestamp,
+ * which are really fixed at the very last step of build process.
+ * They are compiled with __weak first, and without __weak later.
+ */
+
+struct uts_namespace init_uts_ns __weak;
+const char linux_banner[] __weak;
+
+#include "version-timestamp.c"
+
+EXPORT_SYMBOL_GPL(init_uts_ns);