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, 77 insertions, 0 deletions

diff --git a/drivers/net/team/Kconfig b/drivers/net/team/Kconfig
new file mode 100644
index 000000000..4d449845d
--- /dev/null
+++ b/drivers/net/team/Kconfig
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig NET_TEAM
+	tristate "Ethernet team driver support"
+	help
+	  This allows one to create virtual interfaces that teams together
+	  multiple ethernet devices.
+
+	  Team devices can be added using the "ip" command from the
+	  iproute2 package:
+
+	  "ip link add link [ address MAC ] [ NAME ] type team"
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called team.
+
+if NET_TEAM
+
+config NET_TEAM_MODE_BROADCAST
+	tristate "Broadcast mode support"
+	depends on NET_TEAM
+	help
+	  Basic mode where packets are transmitted always by all suitable ports.
+
+	  All added ports are setup to have team's device address.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_broadcast.
+
+config NET_TEAM_MODE_ROUNDROBIN
+	tristate "Round-robin mode support"
+	depends on NET_TEAM
+	help
+	  Basic mode where port used for transmitting packets is selected in
+	  round-robin fashion using packet counter.
+
+	  All added ports are setup to have team's device address.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_roundrobin.
+
+config NET_TEAM_MODE_RANDOM
+	tristate "Random mode support"
+	depends on NET_TEAM
+	help
+	  Basic mode where port used for transmitting packets is selected
+	  randomly.
+
+	  All added ports are setup to have team's device address.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_random.
+
+config NET_TEAM_MODE_ACTIVEBACKUP
+	tristate "Active-backup mode support"
+	depends on NET_TEAM
+	help
+	  Only one port is active at a time and the rest of ports are used
+	  for backup.
+
+	  Mac addresses of ports are not modified. Userspace is responsible
+	  to do so.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_activebackup.
+
+config NET_TEAM_MODE_LOADBALANCE
+	tristate "Load-balance mode support"
+	depends on NET_TEAM
+	help
+	  This mode provides load balancing functionality. Tx port selection
+	  is done using BPF function set up from userspace (bpf_hash_func
+	  option)
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_loadbalance.
+
+endif # NET_TEAM