From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- drivers/pps/Kconfig | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 drivers/pps/Kconfig (limited to 'drivers/pps/Kconfig') diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig new file mode 100644 index 000000000..e1651d51c --- /dev/null +++ b/drivers/pps/Kconfig @@ -0,0 +1,45 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# PPS support configuration +# + +menuconfig PPS + tristate "PPS support" + help + PPS (Pulse Per Second) is a special pulse provided by some GPS + antennae. Userland can use it to get a high-precision time + reference. + + Some antennae's PPS signals are connected with the CD (Carrier + Detect) pin of the serial line they use to communicate with the + host. In this case use the SERIAL_LINE client support. + + Some antennae's PPS signals are connected with some special host + inputs so you have to enable the corresponding client support. + + To compile this driver as a module, choose M here: the module + will be called pps_core.ko. + +if PPS + +config PPS_DEBUG + bool "PPS debugging messages" + help + Say Y here if you want the PPS support to produce a bunch of debug + messages to the system log. Select this if you are having a + problem with PPS support and want to see more of what is going on. + +config NTP_PPS + bool "PPS kernel consumer support" + depends on !NO_HZ_COMMON + help + This option adds support for direct in-kernel time + synchronization using an external PPS signal. + + It doesn't work on tickless systems at the moment. + +source "drivers/pps/clients/Kconfig" + +source "drivers/pps/generators/Kconfig" + +endif # PPS -- cgit v1.3.1