6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nam Cao namcao@linutronix.de
[ Upstream commit eee00df8e1f1f5648ed8f9e40e2bb54c2877344a ]
The field 'function' of struct hrtimer should not be changed directly, as the write is lockless and a concurrent timer expiry might end up using the wrong function pointer.
Switch to use hrtimer_update_function() which also performs runtime checks that it is safe to modify the callback.
Signed-off-by: Nam Cao namcao@linutronix.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/all/af7823518fb060c6c97105a2513cfc61adbdf38f.1738746... Stable-dep-of: 267ee93c417e ("serial: xilinx_uartps: fix rs485 delay_rts_after_send") Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/xilinx_uartps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -454,7 +454,7 @@ static void cdns_uart_handle_tx(void *de
if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED && (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port))) { - cdns_uart->tx_timer.function = &cdns_rs485_rx_callback; + hrtimer_update_function(&cdns_uart->tx_timer, cdns_rs485_rx_callback); hrtimer_start(&cdns_uart->tx_timer, ns_to_ktime(cdns_calc_after_tx_delay(cdns_uart)), HRTIMER_MODE_REL); } @@ -734,7 +734,7 @@ static void cdns_uart_start_tx(struct ua
if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED) { if (!cdns_uart->rs485_tx_started) { - cdns_uart->tx_timer.function = &cdns_rs485_tx_callback; + hrtimer_update_function(&cdns_uart->tx_timer, cdns_rs485_tx_callback); cdns_rs485_tx_setup(cdns_uart); return hrtimer_start(&cdns_uart->tx_timer, ms_to_ktime(port->rs485.delay_rts_before_send),