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 --- net/phonet/sysctl.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 net/phonet/sysctl.c (limited to 'net/phonet/sysctl.c') diff --git a/net/phonet/sysctl.c b/net/phonet/sysctl.c new file mode 100644 index 000000000..463a74a27 --- /dev/null +++ b/net/phonet/sysctl.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * File: sysctl.c + * + * Phonet /proc/sys/net/phonet interface implementation + * + * Copyright (C) 2008 Nokia Corporation. + * + * Author: Rémi Denis-Courmont + */ + +#include +#include +#include +#include + +#include +#include +#include + +#define DYNAMIC_PORT_MIN 0x40 +#define DYNAMIC_PORT_MAX 0x7f + +static DEFINE_SEQLOCK(local_port_range_lock); +static int local_port_range_min[2] = {0, 0}; +static int local_port_range_max[2] = {1023, 1023}; +static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX}; +static struct ctl_table_header *phonet_table_hrd; + +static void set_local_port_range(int range[2]) +{ + write_seqlock(&local_port_range_lock); + local_port_range[0] = range[0]; + local_port_range[1] = range[1]; + write_sequnlock(&local_port_range_lock); +} + +void phonet_get_local_port_range(int *min, int *max) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&local_port_range_lock); + if (min) + *min = local_port_range[0]; + if (max) + *max = local_port_range[1]; + } while (read_seqretry(&local_port_range_lock, seq)); +} + +static int proc_local_port_range(const struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int ret; + int range[2] = {local_port_range[0], local_port_range[1]}; + struct ctl_table tmp = { + .data = &range, + .maxlen = sizeof(range), + .mode = table->mode, + .extra1 = &local_port_range_min, + .extra2 = &local_port_range_max, + }; + + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + + if (write && ret == 0) { + if (range[1] < range[0]) + ret = -EINVAL; + else + set_local_port_range(range); + } + + return ret; +} + +static struct ctl_table phonet_table[] = { + { + .procname = "local_port_range", + .data = &local_port_range, + .maxlen = sizeof(local_port_range), + .mode = 0644, + .proc_handler = proc_local_port_range, + }, +}; + +int __init phonet_sysctl_init(void) +{ + phonet_table_hrd = register_net_sysctl(&init_net, "net/phonet", phonet_table); + return phonet_table_hrd == NULL ? -ENOMEM : 0; +} + +void phonet_sysctl_exit(void) +{ + unregister_net_sysctl_table(phonet_table_hrd); +} -- cgit v1.3.1