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, 35 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-dbg.c b/drivers/usb/host/xhci-dbg.c
new file mode 100644
index 000000000..386abf266
--- /dev/null
+++ b/drivers/usb/host/xhci-dbg.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * xHCI host controller driver
+ *
+ * Copyright (C) 2008 Intel Corp.
+ *
+ * Author: Sarah Sharp
+ * Some code borrowed from the Linux EHCI driver.
+ */
+
+#include "xhci.h"
+
+char *xhci_get_slot_state(struct xhci_hcd *xhci,
+		struct xhci_container_ctx *ctx)
+{
+	struct xhci_slot_ctx *slot_ctx = xhci_get_slot_ctx(xhci, ctx);
+	int state = GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state));
+
+	return xhci_slot_state_string(state);
+}
+
+void xhci_dbg_trace(struct xhci_hcd *xhci, void (*trace)(struct va_format *),
+			const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	xhci_dbg(xhci, "%pV\n", &vaf);
+	trace(&vaf);
+	va_end(args);
+}
+EXPORT_SYMBOL_GPL(xhci_dbg_trace);