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, 56 insertions, 0 deletions

diff --git a/include/uapi/fwctl/cxl.h b/include/uapi/fwctl/cxl.h
new file mode 100644
index 000000000..43f522f0c
--- /dev/null
+++ b/include/uapi/fwctl/cxl.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2024-2025 Intel Corporation
+ *
+ * These are definitions for the mailbox command interface of CXL subsystem.
+ */
+#ifndef _UAPI_FWCTL_CXL_H_
+#define _UAPI_FWCTL_CXL_H_
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <cxl/features.h>
+
+/**
+ * struct fwctl_rpc_cxl - ioctl(FWCTL_RPC) input for CXL
+ * @opcode: CXL mailbox command opcode
+ * @flags: Flags for the command (input).
+ * @op_size: Size of input payload.
+ * @reserved1: Reserved. Must be 0s.
+ * @get_sup_feats_in: Get Supported Features input
+ * @get_feat_in: Get Feature input
+ * @set_feat_in: Set Feature input
+ */
+struct fwctl_rpc_cxl {
+	__struct_group(fwctl_rpc_cxl_hdr, hdr, /* no attrs */,
+		__u32 opcode;
+		__u32 flags;
+		__u32 op_size;
+		__u32 reserved1;
+	);
+	union {
+		struct cxl_mbox_get_sup_feats_in get_sup_feats_in;
+		struct cxl_mbox_get_feat_in get_feat_in;
+		struct cxl_mbox_set_feat_in set_feat_in;
+	};
+};
+
+/**
+ * struct fwctl_rpc_cxl_out - ioctl(FWCTL_RPC) output for CXL
+ * @size: Size of the output payload
+ * @retval: Return value from device
+ * @get_sup_feats_out: Get Supported Features output
+ * @payload: raw byte stream of payload
+ */
+struct fwctl_rpc_cxl_out {
+	__struct_group(fwctl_rpc_cxl_out_hdr, hdr, /* no attrs */,
+		__u32 size;
+		__u32 retval;
+	);
+	union {
+		struct cxl_mbox_get_sup_feats_out get_sup_feats_out;
+		__DECLARE_FLEX_ARRAY(__u8, payload);
+	};
+};
+
+#endif