ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 218 insertions, 0 deletions

diff --git a/net/xfrm/trace_iptfs.h b/net/xfrm/trace_iptfs.h
new file mode 100644
index 000000000..74391ba24
--- /dev/null
+++ b/net/xfrm/trace_iptfs.h
@@ -0,0 +1,218 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* xfrm_trace_iptfs.h
+ *
+ * August 12 2023, Christian Hopps <chopps@labn.net>
+ *
+ * Copyright (c) 2023, LabN Consulting, L.L.C.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM iptfs
+
+#if !defined(_TRACE_IPTFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_IPTFS_H
+
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/tracepoint.h>
+#include <net/ip.h>
+
+struct xfrm_iptfs_data;
+
+TRACE_EVENT(iptfs_egress_recv,
+	    TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u16 blkoff),
+	    TP_ARGS(skb, xtfs, blkoff),
+	    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+			     __field(void *, head)
+			     __field(void *, head_pg_addr)
+			     __field(void *, pg0addr)
+			     __field(u32, skb_len)
+			     __field(u32, data_len)
+			     __field(u32, headroom)
+			     __field(u32, tailroom)
+			     __field(u32, tail)
+			     __field(u32, end)
+			     __field(u32, pg0off)
+			     __field(u8, head_frag)
+			     __field(u8, frag_list)
+			     __field(u8, nr_frags)
+			     __field(u16, blkoff)),
+	    TP_fast_assign(__entry->skb = skb;
+			   __entry->head = skb->head;
+			   __entry->skb_len = skb->len;
+			   __entry->data_len = skb->data_len;
+			   __entry->headroom = skb_headroom(skb);
+			   __entry->tailroom = skb_tailroom(skb);
+			   __entry->tail = (u32)skb->tail;
+			   __entry->end = (u32)skb->end;
+			   __entry->head_frag = skb->head_frag;
+			   __entry->frag_list = (bool)skb_shinfo(skb)->frag_list;
+			   __entry->nr_frags = skb_shinfo(skb)->nr_frags;
+			   __entry->blkoff = blkoff;
+			   __entry->head_pg_addr = page_address(virt_to_head_page(skb->head));
+			   __entry->pg0addr = (__entry->nr_frags
+					       ? page_address(netmem_to_page(skb_shinfo(skb)->frags[0].netmem))
+					       : NULL);
+			   __entry->pg0off = (__entry->nr_frags
+					      ? skb_shinfo(skb)->frags[0].offset
+					      : 0);
+		    ),
+	    TP_printk("EGRESS: skb=%p len=%u data_len=%u headroom=%u head_frag=%u frag_list=%u nr_frags=%u blkoff=%u\n\t\ttailroom=%u tail=%u end=%u head=%p hdpgaddr=%p pg0->addr=%p pg0->data=%p pg0->off=%u",
+		      __entry->skb, __entry->skb_len, __entry->data_len, __entry->headroom,
+		      __entry->head_frag, __entry->frag_list, __entry->nr_frags, __entry->blkoff,
+		      __entry->tailroom, __entry->tail, __entry->end, __entry->head,
+		      __entry->head_pg_addr, __entry->pg0addr, __entry->pg0addr + __entry->pg0off,
+		      __entry->pg0off)
+	)
+
+DECLARE_EVENT_CLASS(iptfs_ingress_preq_event,
+		    TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs,
+			     u32 pmtu, u8 was_gso),
+		    TP_ARGS(skb, xtfs, pmtu, was_gso),
+		    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+				     __field(u32, skb_len)
+				     __field(u32, data_len)
+				     __field(u32, pmtu)
+				     __field(u32, queue_size)
+				     __field(u32, proto_seq)
+				     __field(u8, proto)
+				     __field(u8, was_gso)
+			    ),
+		    TP_fast_assign(__entry->skb = skb;
+				   __entry->skb_len = skb->len;
+				   __entry->data_len = skb->data_len;
+				   __entry->queue_size =
+					xtfs->cfg.max_queue_size - xtfs->queue_size;
+				   __entry->proto = __trace_ip_proto(ip_hdr(skb));
+				   __entry->proto_seq = __trace_ip_proto_seq(ip_hdr(skb));
+				   __entry->pmtu = pmtu;
+				   __entry->was_gso = was_gso;
+			    ),
+		    TP_printk("INGRPREQ: skb=%p len=%u data_len=%u qsize=%u proto=%u proto_seq=%u pmtu=%u was_gso=%u",
+			      __entry->skb, __entry->skb_len, __entry->data_len,
+			      __entry->queue_size, __entry->proto, __entry->proto_seq,
+			      __entry->pmtu, __entry->was_gso));
+
+DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_enqueue,
+	     TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso),
+	     TP_ARGS(skb, xtfs, pmtu, was_gso));
+
+DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_no_queue_space,
+	     TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso),
+	     TP_ARGS(skb, xtfs, pmtu, was_gso));
+
+DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_too_big,
+	     TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso),
+	     TP_ARGS(skb, xtfs, pmtu, was_gso));
+
+DECLARE_EVENT_CLASS(iptfs_ingress_postq_event,
+		    TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, struct iphdr *iph),
+		    TP_ARGS(skb, mtu, blkoff, iph),
+		    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+				     __field(u32, skb_len)
+				     __field(u32, data_len)
+				     __field(u32, mtu)
+				     __field(u32, proto_seq)
+				     __field(u16, blkoff)
+				     __field(u8, proto)),
+		    TP_fast_assign(__entry->skb = skb;
+				   __entry->skb_len = skb->len;
+				   __entry->data_len = skb->data_len;
+				   __entry->mtu = mtu;
+				   __entry->blkoff = blkoff;
+				   __entry->proto = iph ? __trace_ip_proto(iph) : 0;
+				   __entry->proto_seq = iph ? __trace_ip_proto_seq(iph) : 0;
+			    ),
+		    TP_printk("INGRPSTQ: skb=%p len=%u data_len=%u mtu=%u blkoff=%u proto=%u proto_seq=%u",
+			      __entry->skb, __entry->skb_len, __entry->data_len, __entry->mtu,
+			      __entry->blkoff, __entry->proto, __entry->proto_seq));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_dequeue,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_fragmenting,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_final_fragment,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_toobig,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+TRACE_EVENT(iptfs_ingress_nth_peek,
+	    TP_PROTO(struct sk_buff *skb, u32 remaining),
+	    TP_ARGS(skb, remaining),
+	    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+			     __field(u32, skb_len)
+			     __field(u32, remaining)),
+	    TP_fast_assign(__entry->skb = skb;
+			   __entry->skb_len = skb->len;
+			   __entry->remaining = remaining;
+		    ),
+	    TP_printk("INGRPSTQ: NTHPEEK: skb=%p len=%u remaining=%u",
+		      __entry->skb, __entry->skb_len, __entry->remaining));
+
+TRACE_EVENT(iptfs_ingress_nth_add, TP_PROTO(struct sk_buff *skb, u8 share_ok),
+	    TP_ARGS(skb, share_ok),
+	    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+			     __field(u32, skb_len)
+			     __field(u32, data_len)
+			     __field(u8, share_ok)
+			     __field(u8, head_frag)
+			     __field(u8, pp_recycle)
+			     __field(u8, cloned)
+			     __field(u8, shared)
+			     __field(u8, nr_frags)
+			     __field(u8, frag_list)
+		    ),
+	    TP_fast_assign(__entry->skb = skb;
+			   __entry->skb_len = skb->len;
+			   __entry->data_len = skb->data_len;
+			   __entry->share_ok = share_ok;
+			   __entry->head_frag = skb->head_frag;
+			   __entry->pp_recycle = skb->pp_recycle;
+			   __entry->cloned = skb_cloned(skb);
+			   __entry->shared = skb_shared(skb);
+			   __entry->nr_frags = skb_shinfo(skb)->nr_frags;
+			   __entry->frag_list = (bool)skb_shinfo(skb)->frag_list;
+		    ),
+	    TP_printk("INGRPSTQ: NTHADD: skb=%p len=%u data_len=%u share_ok=%u head_frag=%u pp_recycle=%u cloned=%u shared=%u nr_frags=%u frag_list=%u",
+		      __entry->skb, __entry->skb_len, __entry->data_len, __entry->share_ok,
+		      __entry->head_frag, __entry->pp_recycle, __entry->cloned, __entry->shared,
+		      __entry->nr_frags, __entry->frag_list));
+
+DECLARE_EVENT_CLASS(iptfs_timer_event,
+		    TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val),
+		    TP_ARGS(xtfs, time_val),
+		    TP_STRUCT__entry(__field(u64, time_val)
+				     __field(u64, set_time)),
+		    TP_fast_assign(__entry->time_val = time_val;
+				   __entry->set_time = xtfs->iptfs_settime;
+			    ),
+		    TP_printk("TIMER: set_time=%llu time_val=%llu",
+			      __entry->set_time, __entry->time_val));
+
+DEFINE_EVENT(iptfs_timer_event, iptfs_timer_start,
+	     TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val),
+	     TP_ARGS(xtfs, time_val));
+
+DEFINE_EVENT(iptfs_timer_event, iptfs_timer_expire,
+	     TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val),
+	     TP_ARGS(xtfs, time_val));
+
+#endif /* _TRACE_IPTFS_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH ../../net/xfrm
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_iptfs
+#include <trace/define_trace.h>