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, 281 insertions, 0 deletions

diff --git a/include/trace/events/filelock.h b/include/trace/events/filelock.h
new file mode 100644
index 000000000..f11284be0
--- /dev/null
+++ b/include/trace/events/filelock.h
@@ -0,0 +1,281 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Events for filesystem locks
+ *
+ * Copyright 2013 Jeff Layton <jlayton@poochiereds.net>
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM filelock
+
+#if !defined(_TRACE_FILELOCK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FILELOCK_H
+
+#include <linux/tracepoint.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/kdev_t.h>
+
+#define show_fl_flags(val)						\
+	__print_flags(val, "|", 					\
+		{ FL_POSIX,		"FL_POSIX" },			\
+		{ FL_FLOCK,		"FL_FLOCK" },			\
+		{ FL_DELEG,		"FL_DELEG" },			\
+		{ FL_ACCESS,		"FL_ACCESS" },			\
+		{ FL_EXISTS,		"FL_EXISTS" },			\
+		{ FL_LEASE,		"FL_LEASE" },			\
+		{ FL_CLOSE,		"FL_CLOSE" },			\
+		{ FL_SLEEP,		"FL_SLEEP" },			\
+		{ FL_DOWNGRADE_PENDING,	"FL_DOWNGRADE_PENDING" },	\
+		{ FL_UNLOCK_PENDING,	"FL_UNLOCK_PENDING" },		\
+		{ FL_OFDLCK,		"FL_OFDLCK" },			\
+		{ FL_RECLAIM,		"FL_RECLAIM" },			\
+		{ FL_IGN_DIR_CREATE,	"FL_IGN_DIR_CREATE" },		\
+		{ FL_IGN_DIR_DELETE,	"FL_IGN_DIR_DELETE" },		\
+		{ FL_IGN_DIR_RENAME,	"FL_IGN_DIR_RENAME" })
+
+#define show_fl_type(val)				\
+	__print_symbolic(val,				\
+			{ F_RDLCK, "F_RDLCK" },		\
+			{ F_WRLCK, "F_WRLCK" },		\
+			{ F_UNLCK, "F_UNLCK" })
+
+TRACE_EVENT(locks_get_lock_context,
+	TP_PROTO(struct inode *inode, int type, struct file_lock_context *ctx),
+
+	TP_ARGS(inode, type, ctx),
+
+	TP_STRUCT__entry(
+		__field(u64, i_ino)
+		__field(struct file_lock_context *, ctx)
+		__field(dev_t, s_dev)
+		__field(unsigned char, type)
+	),
+
+	TP_fast_assign(
+		__entry->s_dev = inode->i_sb->s_dev;
+		__entry->i_ino = inode->i_ino;
+		__entry->type = type;
+		__entry->ctx = ctx;
+	),
+
+	TP_printk("dev=0x%x:0x%x ino=0x%llx type=%s ctx=%p",
+		  MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		  __entry->i_ino, show_fl_type(__entry->type), __entry->ctx)
+);
+
+DECLARE_EVENT_CLASS(filelock_lock,
+	TP_PROTO(struct inode *inode, struct file_lock *fl, int ret),
+
+	TP_ARGS(inode, fl, ret),
+
+	TP_STRUCT__entry(
+		__field(u64, i_ino)
+		__field(loff_t, fl_start)
+		__field(loff_t, fl_end)
+		__field(struct file_lock *, fl)
+		__field(struct file_lock_core *, blocker)
+		__field(fl_owner_t, owner)
+		__field(dev_t, s_dev)
+		__field(unsigned int, pid)
+		__field(unsigned int, flags)
+		__field(unsigned char, type)
+		__field(int, ret)
+	),
+
+	TP_fast_assign(
+		__entry->fl = fl ? fl : NULL;
+		__entry->s_dev = inode->i_sb->s_dev;
+		__entry->i_ino = inode->i_ino;
+		__entry->blocker = fl ? fl->c.flc_blocker : NULL;
+		__entry->owner = fl ? fl->c.flc_owner : NULL;
+		__entry->pid = fl ? fl->c.flc_pid : 0;
+		__entry->flags = fl ? fl->c.flc_flags : 0;
+		__entry->type = fl ? fl->c.flc_type : 0;
+		__entry->fl_start = fl ? fl->fl_start : 0;
+		__entry->fl_end = fl ? fl->fl_end : 0;
+		__entry->ret = ret;
+	),
+
+	TP_printk("fl=%p dev=0x%x:0x%x ino=0x%llx fl_blocker=%p fl_owner=%p fl_pid=%u fl_flags=%s fl_type=%s fl_start=%lld fl_end=%lld ret=%d",
+		__entry->fl, MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		__entry->i_ino, __entry->blocker, __entry->owner,
+		__entry->pid, show_fl_flags(__entry->flags),
+		show_fl_type(__entry->type),
+		__entry->fl_start, __entry->fl_end, __entry->ret)
+);
+
+DEFINE_EVENT(filelock_lock, posix_lock_inode,
+		TP_PROTO(struct inode *inode, struct file_lock *fl, int ret),
+		TP_ARGS(inode, fl, ret));
+
+DEFINE_EVENT(filelock_lock, fcntl_setlk,
+		TP_PROTO(struct inode *inode, struct file_lock *fl, int ret),
+		TP_ARGS(inode, fl, ret));
+
+DEFINE_EVENT(filelock_lock, locks_remove_posix,
+		TP_PROTO(struct inode *inode, struct file_lock *fl, int ret),
+		TP_ARGS(inode, fl, ret));
+
+DEFINE_EVENT(filelock_lock, flock_lock_inode,
+		TP_PROTO(struct inode *inode, struct file_lock *fl, int ret),
+		TP_ARGS(inode, fl, ret));
+
+#define show_lease_break_flags(val)					\
+	__print_flags(val, "|",						\
+		{ LEASE_BREAK_LEASE,		"LEASE" },		\
+		{ LEASE_BREAK_DELEG,		"DELEG" },		\
+		{ LEASE_BREAK_LAYOUT,		"LAYOUT" },		\
+		{ LEASE_BREAK_NONBLOCK,		"NONBLOCK" },		\
+		{ LEASE_BREAK_OPEN_RDONLY,	"OPEN_RDONLY" },	\
+		{ LEASE_BREAK_DIR_CREATE,	"DIR_CREATE" },		\
+		{ LEASE_BREAK_DIR_DELETE,	"DIR_DELETE" },		\
+		{ LEASE_BREAK_DIR_RENAME,	"DIR_RENAME" })
+
+TRACE_EVENT(break_lease,
+	TP_PROTO(struct inode *inode, unsigned int flags),
+
+	TP_ARGS(inode, flags),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, i_ino)
+		__field(dev_t, s_dev)
+		__field(unsigned int, flags)
+	),
+
+	TP_fast_assign(
+		__entry->s_dev = inode->i_sb->s_dev;
+		__entry->i_ino = inode->i_ino;
+		__entry->flags = flags;
+	),
+
+	TP_printk("dev=0x%x:0x%x ino=0x%lx flags=%s",
+		  MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		  __entry->i_ino, show_lease_break_flags(__entry->flags))
+);
+
+DECLARE_EVENT_CLASS(filelock_lease,
+	TP_PROTO(struct inode *inode, struct file_lease *fl),
+
+	TP_ARGS(inode, fl),
+
+	TP_STRUCT__entry(
+		__field(u64, i_ino)
+		__field(struct file_lease *, fl)
+		__field(struct file_lock_core *, blocker)
+		__field(fl_owner_t, owner)
+		__field(unsigned long, break_time)
+		__field(unsigned long, downgrade_time)
+		__field(dev_t, s_dev)
+		__field(unsigned int, flags)
+		__field(unsigned char, type)
+	),
+
+	TP_fast_assign(
+		__entry->fl = fl ? fl : NULL;
+		__entry->s_dev = inode->i_sb->s_dev;
+		__entry->i_ino = inode->i_ino;
+		__entry->blocker = fl ? fl->c.flc_blocker : NULL;
+		__entry->owner = fl ? fl->c.flc_owner : NULL;
+		__entry->flags = fl ? fl->c.flc_flags : 0;
+		__entry->type = fl ? fl->c.flc_type : 0;
+		__entry->break_time = fl ? fl->fl_break_time : 0;
+		__entry->downgrade_time = fl ? fl->fl_downgrade_time : 0;
+	),
+
+	TP_printk("fl=%p dev=0x%x:0x%x ino=0x%llx fl_blocker=%p fl_owner=%p fl_flags=%s fl_type=%s fl_break_time=%lu fl_downgrade_time=%lu",
+		__entry->fl, MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		__entry->i_ino, __entry->blocker, __entry->owner,
+		show_fl_flags(__entry->flags),
+		show_fl_type(__entry->type),
+		__entry->break_time, __entry->downgrade_time)
+);
+
+DEFINE_EVENT(filelock_lease, break_lease_noblock, TP_PROTO(struct inode *inode, struct file_lease *fl),
+		TP_ARGS(inode, fl));
+
+DEFINE_EVENT(filelock_lease, break_lease_block, TP_PROTO(struct inode *inode, struct file_lease *fl),
+		TP_ARGS(inode, fl));
+
+DEFINE_EVENT(filelock_lease, break_lease_unblock, TP_PROTO(struct inode *inode, struct file_lease *fl),
+		TP_ARGS(inode, fl));
+
+DEFINE_EVENT(filelock_lease, generic_delete_lease, TP_PROTO(struct inode *inode, struct file_lease *fl),
+		TP_ARGS(inode, fl));
+
+DEFINE_EVENT(filelock_lease, time_out_leases, TP_PROTO(struct inode *inode, struct file_lease *fl),
+		TP_ARGS(inode, fl));
+
+TRACE_EVENT(generic_add_lease,
+	TP_PROTO(struct inode *inode, struct file_lease *fl),
+
+	TP_ARGS(inode, fl),
+
+	TP_STRUCT__entry(
+		__field(u64, i_ino)
+		__field(fl_owner_t, owner)
+		__field(dev_t, s_dev)
+		__field(int, wcount)
+		__field(int, rcount)
+		__field(int, icount)
+		__field(unsigned int, flags)
+		__field(unsigned char, type)
+	),
+
+	TP_fast_assign(
+		__entry->s_dev = inode->i_sb->s_dev;
+		__entry->i_ino = inode->i_ino;
+		__entry->wcount = atomic_read(&inode->i_writecount);
+		__entry->rcount = atomic_read(&inode->i_readcount);
+		__entry->icount = icount_read_once(inode);
+		__entry->owner = fl->c.flc_owner;
+		__entry->flags = fl->c.flc_flags;
+		__entry->type = fl->c.flc_type;
+	),
+
+	TP_printk("dev=0x%x:0x%x ino=0x%llx wcount=%d rcount=%d icount=%d fl_owner=%p fl_flags=%s fl_type=%s",
+		MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		__entry->i_ino, __entry->wcount, __entry->rcount,
+		__entry->icount, __entry->owner,
+		show_fl_flags(__entry->flags),
+		show_fl_type(__entry->type))
+);
+
+TRACE_EVENT(leases_conflict,
+	TP_PROTO(bool conflict, struct file_lease *lease, struct file_lease *breaker),
+
+	TP_ARGS(conflict, lease, breaker),
+
+	TP_STRUCT__entry(
+		__field(void *, lease)
+		__field(void *, breaker)
+		__field(unsigned int, l_fl_flags)
+		__field(unsigned int, b_fl_flags)
+		__field(unsigned char, l_fl_type)
+		__field(unsigned char, b_fl_type)
+		__field(bool, conflict)
+	),
+
+	TP_fast_assign(
+		__entry->lease = lease;
+		__entry->l_fl_flags = lease->c.flc_flags;
+		__entry->l_fl_type = lease->c.flc_type;
+		__entry->breaker = breaker;
+		__entry->b_fl_flags = breaker->c.flc_flags;
+		__entry->b_fl_type = breaker->c.flc_type;
+		__entry->conflict = conflict;
+	),
+
+	TP_printk("conflict %d: lease=%p fl_flags=%s fl_type=%s; breaker=%p fl_flags=%s fl_type=%s",
+		__entry->conflict,
+		__entry->lease,
+		show_fl_flags(__entry->l_fl_flags),
+		show_fl_type(__entry->l_fl_type),
+		__entry->breaker,
+		show_fl_flags(__entry->b_fl_flags),
+		show_fl_type(__entry->b_fl_type))
+);
+
+#endif /* _TRACE_FILELOCK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>