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/batman-adv/bitarray.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 net/batman-adv/bitarray.h (limited to 'net/batman-adv/bitarray.h') diff --git a/net/batman-adv/bitarray.h b/net/batman-adv/bitarray.h new file mode 100644 index 000000000..2b9f5dbb3 --- /dev/null +++ b/net/batman-adv/bitarray.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors: + * + * Simon Wunderlich, Marek Lindner + */ + +#ifndef _NET_BATMAN_ADV_BITARRAY_H_ +#define _NET_BATMAN_ADV_BITARRAY_H_ + +#include "main.h" + +#include +#include +#include +#include + +/** + * batadv_test_bit() - check if bit is set in the current window + * + * @seq_bits: pointer to the sequence number bitmap of received packets + * @last_seqno: latest sequence number in seq_bits + * @curr_seqno: sequence number to test for + * + * Return: true if the corresponding bit in the given seq_bits indicates true + * and curr_seqno is within range of last_seqno. Otherwise returns false. + */ +static inline bool batadv_test_bit(const unsigned long *seq_bits, + u32 last_seqno, u32 curr_seqno) +{ + s32 diff; + + diff = last_seqno - curr_seqno; + if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE) + return false; + return test_bit(diff, seq_bits) != 0; +} + +/** + * batadv_set_bit() - Turn corresponding bit on, so we can remember that we got + * the packet + * @seq_bits: bitmap of the packet receive window + * @n: relative sequence number of newly received packet + */ +static inline void batadv_set_bit(unsigned long *seq_bits, s32 n) +{ + /* if too old, just drop it */ + if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE) + return; + + set_bit(n, seq_bits); /* turn the position on */ +} + +bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits, + s32 seq_num_diff, int set_mark); + +#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */ -- cgit v1.3.1