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| author | Steven Rostedt <rostedt@goodmis.org> | 2026-09-02 09:55:01 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-09-02 11:08:21 -0400 |
| commit | 4617721c502b2ddaa4e324e86da4997edf738fa5 (patch) | |
| tree | 350aa83b47da0b574a814795392b20b0bed83cbc /drivers/tty/serial/timbuart.h | |
| download | linux-stable-4617721c502b2ddaa4e324e86da4997edf738fa5.tar.gz linux-stable-4617721c502b2ddaa4e324e86da4997edf738fa5.zip | |
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>
Diffstat (limited to 'drivers/tty/serial/timbuart.h')
| -rw-r--r-- | drivers/tty/serial/timbuart.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/tty/serial/timbuart.h b/drivers/tty/serial/timbuart.h new file mode 100644 index 000000000..007e59af6 --- /dev/null +++ b/drivers/tty/serial/timbuart.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * timbuart.c timberdale FPGA GPIO driver + * Copyright (c) 2009 Intel Corporation + */ + +/* Supports: + * Timberdale FPGA UART + */ + +#ifndef _TIMBUART_H +#define _TIMBUART_H + +#define TIMBUART_FIFO_SIZE 2048 + +#define TIMBUART_RXFIFO 0x08 +#define TIMBUART_TXFIFO 0x0c +#define TIMBUART_IER 0x10 +#define TIMBUART_IPR 0x14 +#define TIMBUART_ISR 0x18 +#define TIMBUART_CTRL 0x1c +#define TIMBUART_BAUDRATE 0x20 + +#define TIMBUART_CTRL_RTS 0x01 +#define TIMBUART_CTRL_CTS 0x02 +#define TIMBUART_CTRL_FLSHTX 0x40 +#define TIMBUART_CTRL_FLSHRX 0x80 + +#define TXBF 0x01 +#define TXBAE 0x02 +#define CTS_DELTA 0x04 +#define RXDP 0x08 +#define RXBAF 0x10 +#define RXBF 0x20 +#define RXTT 0x40 +#define RXBNAE 0x80 +#define TXBE 0x100 + +#define RXFLAGS (RXDP | RXBAF | RXBF | RXTT | RXBNAE) +#define TXFLAGS (TXBF | TXBAE) + +#define TIMBUART_MAJOR 204 +#define TIMBUART_MINOR 192 + +#endif /* _TIMBUART_H */ + |