Fix two races related TCSADRAIN/FLUSH. One in tty core and the other that can occur when 8250 UART is using DMA for Tx. These might be slightly controversial as it requires userspace to race write() with tcsetattr() to trigger these races. But since the races still seem fixable on kernel side, I made these patches. v2: - Switch DMA Tx running / LSR Tx empty checks order due to fast/slowness - Calculate the result in serial8250_tx_empty() directly Ilpo Järvinen (2): tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH serial: 8250: Fix serial8250_tx_empty() race with DMA Tx drivers/tty/serial/8250/8250.h | 12 ++++++++ drivers/tty/serial/8250/8250_port.c | 7 +++-- drivers/tty/tty.h | 2 ++ drivers/tty/tty_io.c | 4 +-- drivers/tty/tty_ioctl.c | 45 +++++++++++++++++++++-------- 5 files changed, 53 insertions(+), 17 deletions(-) -- 2.30.2
