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, 242 insertions, 0 deletions

diff --git a/drivers/misc/ocxl/trace.h b/drivers/misc/ocxl/trace.h
new file mode 100644
index 000000000..a33a5094f
--- /dev/null
+++ b/drivers/misc/ocxl/trace.h
@@ -0,0 +1,242 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+// Copyright 2017 IBM Corp.
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM ocxl
+
+#if !defined(_TRACE_OCXL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_OCXL_H
+
+#include <linux/tracepoint.h>
+
+
+TRACE_EVENT(ocxl_mmu_notifier_range,
+	TP_PROTO(unsigned long start, unsigned long end, unsigned long pidr),
+	TP_ARGS(start, end, pidr),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, start)
+		__field(unsigned long, end)
+		__field(unsigned long, pidr)
+	),
+
+	TP_fast_assign(
+		__entry->start = start;
+		__entry->end = end;
+		__entry->pidr = pidr;
+	),
+
+	TP_printk("start=0x%lx end=0x%lx pidr=0x%lx",
+		__entry->start,
+		__entry->end,
+		__entry->pidr
+	)
+);
+
+TRACE_EVENT(ocxl_init_mmu_notifier,
+	TP_PROTO(int pasid, unsigned long pidr),
+	TP_ARGS(pasid, pidr),
+
+	TP_STRUCT__entry(
+		__field(int, pasid)
+		__field(unsigned long, pidr)
+	),
+
+	TP_fast_assign(
+		__entry->pasid = pasid;
+		__entry->pidr = pidr;
+	),
+
+	TP_printk("pasid=%d, pidr=0x%lx",
+		__entry->pasid,
+		__entry->pidr
+	)
+);
+
+TRACE_EVENT(ocxl_release_mmu_notifier,
+	TP_PROTO(int pasid, unsigned long pidr),
+	TP_ARGS(pasid, pidr),
+
+	TP_STRUCT__entry(
+		__field(int, pasid)
+		__field(unsigned long, pidr)
+	),
+
+	TP_fast_assign(
+		__entry->pasid = pasid;
+		__entry->pidr = pidr;
+	),
+
+	TP_printk("pasid=%d, pidr=0x%lx",
+		__entry->pasid,
+		__entry->pidr
+	)
+);
+
+DECLARE_EVENT_CLASS(ocxl_context,
+	TP_PROTO(pid_t pid, void *spa, int pasid, u32 pidr, u32 tidr),
+	TP_ARGS(pid, spa, pasid, pidr, tidr),
+
+	TP_STRUCT__entry(
+		__field(pid_t, pid)
+		__field(void*, spa)
+		__field(int, pasid)
+		__field(u32, pidr)
+		__field(u32, tidr)
+	),
+
+	TP_fast_assign(
+		__entry->pid = pid;
+		__entry->spa = spa;
+		__entry->pasid = pasid;
+		__entry->pidr = pidr;
+		__entry->tidr = tidr;
+	),
+
+	TP_printk("linux pid=%d spa=0x%p pasid=0x%x pidr=0x%x tidr=0x%x",
+		__entry->pid,
+		__entry->spa,
+		__entry->pasid,
+		__entry->pidr,
+		__entry->tidr
+	)
+);
+
+DEFINE_EVENT(ocxl_context, ocxl_context_add,
+	TP_PROTO(pid_t pid, void *spa, int pasid, u32 pidr, u32 tidr),
+	TP_ARGS(pid, spa, pasid, pidr, tidr)
+);
+
+DEFINE_EVENT(ocxl_context, ocxl_context_remove,
+	TP_PROTO(pid_t pid, void *spa, int pasid, u32 pidr, u32 tidr),
+	TP_ARGS(pid, spa, pasid, pidr, tidr)
+);
+
+TRACE_EVENT(ocxl_terminate_pasid,
+	TP_PROTO(int pasid, int rc),
+	TP_ARGS(pasid, rc),
+
+	TP_STRUCT__entry(
+		__field(int, pasid)
+		__field(int, rc)
+	),
+
+	TP_fast_assign(
+		__entry->pasid = pasid;
+		__entry->rc = rc;
+	),
+
+	TP_printk("pasid=0x%x rc=%d",
+		__entry->pasid,
+		__entry->rc
+	)
+);
+
+DECLARE_EVENT_CLASS(ocxl_fault_handler,
+	TP_PROTO(void *spa, u64 pe, u64 dsisr, u64 dar, u64 tfc),
+	TP_ARGS(spa, pe, dsisr, dar, tfc),
+
+	TP_STRUCT__entry(
+		__field(void *, spa)
+		__field(u64, pe)
+		__field(u64, dsisr)
+		__field(u64, dar)
+		__field(u64, tfc)
+	),
+
+	TP_fast_assign(
+		__entry->spa = spa;
+		__entry->pe = pe;
+		__entry->dsisr = dsisr;
+		__entry->dar = dar;
+		__entry->tfc = tfc;
+	),
+
+	TP_printk("spa=%p pe=0x%llx dsisr=0x%llx dar=0x%llx tfc=0x%llx",
+		__entry->spa,
+		__entry->pe,
+		__entry->dsisr,
+		__entry->dar,
+		__entry->tfc
+	)
+);
+
+DEFINE_EVENT(ocxl_fault_handler, ocxl_fault,
+	TP_PROTO(void *spa, u64 pe, u64 dsisr, u64 dar, u64 tfc),
+	TP_ARGS(spa, pe, dsisr, dar, tfc)
+);
+
+DEFINE_EVENT(ocxl_fault_handler, ocxl_fault_ack,
+	TP_PROTO(void *spa, u64 pe, u64 dsisr, u64 dar, u64 tfc),
+	TP_ARGS(spa, pe, dsisr, dar, tfc)
+);
+
+TRACE_EVENT(ocxl_afu_irq_alloc,
+	TP_PROTO(int pasid, int irq_id, unsigned int virq, int hw_irq),
+	TP_ARGS(pasid, irq_id, virq, hw_irq),
+
+	TP_STRUCT__entry(
+		__field(int, pasid)
+		__field(int, irq_id)
+		__field(unsigned int, virq)
+		__field(int, hw_irq)
+	),
+
+	TP_fast_assign(
+		__entry->pasid = pasid;
+		__entry->irq_id = irq_id;
+		__entry->virq = virq;
+		__entry->hw_irq = hw_irq;
+	),
+
+	TP_printk("pasid=0x%x irq_id=%d virq=%u hw_irq=%d",
+		__entry->pasid,
+		__entry->irq_id,
+		__entry->virq,
+		__entry->hw_irq
+	)
+);
+
+TRACE_EVENT(ocxl_afu_irq_free,
+	TP_PROTO(int pasid, int irq_id),
+	TP_ARGS(pasid, irq_id),
+
+	TP_STRUCT__entry(
+		__field(int, pasid)
+		__field(int, irq_id)
+	),
+
+	TP_fast_assign(
+		__entry->pasid = pasid;
+		__entry->irq_id = irq_id;
+	),
+
+	TP_printk("pasid=0x%x irq_id=%d",
+		__entry->pasid,
+		__entry->irq_id
+	)
+);
+
+TRACE_EVENT(ocxl_afu_irq_receive,
+	TP_PROTO(int virq),
+	TP_ARGS(virq),
+
+	TP_STRUCT__entry(
+		__field(int, virq)
+	),
+
+	TP_fast_assign(
+		__entry->virq = virq;
+	),
+
+	TP_printk("virq=%d",
+		__entry->virq
+	)
+);
+
+#endif /* _TRACE_OCXL_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>