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/net/plip/Kconfig | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 drivers/net/plip/Kconfig (limited to 'drivers/net/plip/Kconfig') diff --git a/drivers/net/plip/Kconfig b/drivers/net/plip/Kconfig new file mode 100644 index 000000000..67bfb01de --- /dev/null +++ b/drivers/net/plip/Kconfig @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Parallel Line Internet Protocol (PLIP) network device configuration +# + +config PLIP + tristate "PLIP (parallel port) support" + depends on PARPORT + help + PLIP (Parallel Line Internet Protocol) is used to create a + reasonably fast mini network consisting of two (or, rarely, more) + local machines. A PLIP link from a Linux box is a popular means to + install a Linux distribution on a machine which doesn't have a + CD-ROM drive (a minimal system has to be transferred with floppies + first). The kernels on both machines need to have this PLIP option + enabled for this to work. + + The PLIP driver has two modes, mode 0 and mode 1. The parallel + ports (the connectors at the computers with 25 holes) are connected + with "null printer" or "Turbo Laplink" cables which can transmit 4 + bits at a time (mode 0) or with special PLIP cables, to be used on + bidirectional parallel ports only, which can transmit 8 bits at a + time (mode 1); you can find the wiring of these cables in + . The cables can be up to + 15m long. Mode 0 works also if one of the machines runs DOS/Windows + and has some PLIP software installed, e.g. the Crynwr PLIP packet + driver () + and winsock or NCSA's telnet. + + If you want to use PLIP, say Y and read the PLIP mini-HOWTO as well + as the NET-3-HOWTO, both available from + . Note that the PLIP + protocol has been changed and this PLIP driver won't work together + with the PLIP support in Linux versions 1.0.x. This option enlarges + your kernel by about 8 KB. + + To compile this driver as a module, choose M here. The module + will be called plip. If unsure, say Y or M, in case you buy + a laptop later. -- cgit v1.3.1