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, 104 insertions, 0 deletions

diff --git a/include/trace/events/fib.h b/include/trace/events/fib.h
new file mode 100644
index 000000000..feb28b359
--- /dev/null
+++ b/include/trace/events/fib.h
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fib
+
+#if !defined(_TRACE_FIB_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FIB_H
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <net/flow.h>
+#include <net/inet_dscp.h>
+#include <net/ip_fib.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(fib_table_lookup,
+
+	TP_PROTO(u32 tb_id, const struct flowi4 *flp,
+		 const struct fib_nh_common *nhc, int err),
+
+	TP_ARGS(tb_id, flp, nhc, err),
+
+	TP_STRUCT__entry(
+		__field(	u32,	tb_id		)
+		__field(	int,	err		)
+		__field(	int,	oif		)
+		__field(	int,	iif		)
+		__field(	u8,	proto		)
+		__field(	__u8,	tos		)
+		__field(	__u8,	scope		)
+		__field(	__u8,	flags		)
+		__array(	__u8,	src,	4	)
+		__array(	__u8,	dst,	4	)
+		__array(	__u8,	gw4,	4	)
+		__array(	__u8,	gw6,	16	)
+		__field(	u16,	sport		)
+		__field(	u16,	dport		)
+		__array(char,  name,   IFNAMSIZ )
+	),
+
+	TP_fast_assign(
+		struct net_device *dev;
+		struct in6_addr *in6;
+		__be32 *p32;
+
+		__entry->tb_id = tb_id;
+		__entry->err = err;
+		__entry->oif = flp->flowi4_oif;
+		__entry->iif = flp->flowi4_iif;
+		__entry->tos = inet_dscp_to_dsfield(flp->flowi4_dscp);
+		__entry->scope = flp->flowi4_scope;
+		__entry->flags = flp->flowi4_flags;
+
+		p32 = (__be32 *) __entry->src;
+		*p32 = flp->saddr;
+
+		p32 = (__be32 *) __entry->dst;
+		*p32 = flp->daddr;
+
+		__entry->proto = flp->flowi4_proto;
+		if (__entry->proto == IPPROTO_TCP ||
+		    __entry->proto == IPPROTO_UDP) {
+			__entry->sport = ntohs(flp->fl4_sport);
+			__entry->dport = ntohs(flp->fl4_dport);
+		} else {
+			__entry->sport = 0;
+			__entry->dport = 0;
+		}
+
+		dev = nhc ? nhc->nhc_dev : NULL;
+		strscpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ);
+
+		if (nhc) {
+			if (nhc->nhc_gw_family == AF_INET) {
+				p32 = (__be32 *) __entry->gw4;
+				*p32 = nhc->nhc_gw.ipv4;
+
+				in6 = (struct in6_addr *)__entry->gw6;
+				*in6 = in6addr_any;
+			} else if (nhc->nhc_gw_family == AF_INET6) {
+				p32 = (__be32 *) __entry->gw4;
+				*p32 = 0;
+
+				in6 = (struct in6_addr *)__entry->gw6;
+				*in6 = nhc->nhc_gw.ipv6;
+			}
+		} else {
+			p32 = (__be32 *) __entry->gw4;
+			*p32 = 0;
+
+			in6 = (struct in6_addr *)__entry->gw6;
+			*in6 = in6addr_any;
+		}
+	),
+
+	TP_printk("table %u oif %d iif %d proto %u %pI4/%u -> %pI4/%u tos %d scope %d flags %x ==> dev %s gw %pI4/%pI6c err %d",
+		  __entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
+		  __entry->src, __entry->sport, __entry->dst, __entry->dport,
+		  __entry->tos, __entry->scope, __entry->flags,
+		  __entry->name, __entry->gw4, __entry->gw6, __entry->err)
+);
+#endif /* _TRACE_FIB_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>