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, 105 insertions, 0 deletions

diff --git a/drivers/usb/usbip/stub.h b/drivers/usb/usbip/stub.h
new file mode 100644
index 000000000..d11270560
--- /dev/null
+++ b/drivers/usb/usbip/stub.h
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ */
+
+#ifndef __USBIP_STUB_H
+#define __USBIP_STUB_H
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/usb.h>
+#include <linux/wait.h>
+
+#define STUB_BUSID_OTHER 0
+#define STUB_BUSID_REMOV 1
+#define STUB_BUSID_ADDED 2
+#define STUB_BUSID_ALLOC 3
+
+struct stub_device {
+	struct usb_device *udev;
+
+	struct usbip_device ud;
+	__u32 devid;
+
+	/*
+	 * stub_priv preserves private data of each urb.
+	 * It is allocated as stub_priv_cache and assigned to urb->context.
+	 *
+	 * stub_priv is always linked to any one of 3 lists;
+	 *	priv_init: linked to this until the comletion of a urb.
+	 *	priv_tx  : linked to this after the completion of a urb.
+	 *	priv_free: linked to this after the sending of the result.
+	 *
+	 * Any of these list operations should be locked by priv_lock.
+	 */
+	spinlock_t priv_lock;
+	struct list_head priv_init;
+	struct list_head priv_tx;
+	struct list_head priv_free;
+
+	/* see comments for unlinking in stub_rx.c */
+	struct list_head unlink_tx;
+	struct list_head unlink_free;
+
+	wait_queue_head_t tx_waitq;
+};
+
+/* private data into urb->priv */
+struct stub_priv {
+	unsigned long seqnum;
+	struct list_head list;
+	struct stub_device *sdev;
+	struct urb **urbs;
+	struct scatterlist *sgl;
+	int num_urbs;
+	int completed_urbs;
+	int urb_status;
+
+	int unlinking;
+};
+
+struct stub_unlink {
+	unsigned long seqnum;
+	struct list_head list;
+	__u32 status;
+};
+
+/* same as SYSFS_BUS_ID_SIZE */
+#define BUSID_SIZE 32
+
+struct bus_id_priv {
+	char name[BUSID_SIZE];
+	char status;
+	int interf_count;
+	struct stub_device *sdev;
+	struct usb_device *udev;
+	char shutdown_busid;
+	spinlock_t busid_lock;
+};
+
+/* stub_priv is allocated from stub_priv_cache */
+extern struct kmem_cache *stub_priv_cache;
+
+/* stub_dev.c */
+extern struct usb_device_driver stub_driver;
+
+/* stub_main.c */
+struct bus_id_priv *get_busid_priv(const char *busid);
+void put_busid_priv(struct bus_id_priv *bid);
+int del_match_busid(char *busid);
+void stub_free_priv_and_urb(struct stub_priv *priv);
+void stub_device_cleanup_urbs(struct stub_device *sdev);
+
+/* stub_rx.c */
+int stub_rx_loop(void *data);
+
+/* stub_tx.c */
+void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
+			     __u32 status);
+void stub_complete(struct urb *urb);
+int stub_tx_loop(void *data);
+
+#endif /* __USBIP_STUB_H */