serial: take termios_rwsem for ->rs485_config() & pass termios as param

To be able to alter ADDRB within ->rs485_config(), take termios_rwsem
before calling ->rs485_config() and pass termios.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 5cc967fe3b597f0d0f94d512a98df6d0b268e91e..287153d325365a542ce14575a1acc9dcb134e5ae 100644 (file)
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -203,7 +203,8 @@ void serial8250_rpm_put(struct uart_8250_port *p);
 void serial8250_rpm_get_tx(struct uart_8250_port *p);
 void serial8250_rpm_put_tx(struct uart_8250_port *p);
 
-int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485);
+int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
+                           struct serial_rs485 *rs485);
 void serial8250_em485_start_tx(struct uart_8250_port *p);
 void serial8250_em485_stop_tx(struct uart_8250_port *p);
 void serial8250_em485_destroy(struct uart_8250_port *p);

diff --git a/drivers/tty/serial/8250/8250_dwlib.c b/drivers/tty/serial/8250/8250_dwlib.c
index c83e7eaf38771e802d6527c6c4874f77864b59e2..d1ff3daeb0ba053e7e8f7e3f0beae963bbc3c42c 100644 (file)
--- a/drivers/tty/serial/8250/8250_dwlib.c
+++ b/drivers/tty/serial/8250/8250_dwlib.c
@@ -85,7 +85,8 @@ void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct
 }
 EXPORT_SYMBOL_GPL(dw8250_do_set_termios);
 
-static int dw8250_rs485_config(struct uart_port *p, struct serial_rs485 *rs485)
+static int dw8250_rs485_config(struct uart_port *p, struct ktermios *termios,
+                              struct serial_rs485 *rs485)
 {
        u32 tcr;
 

diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 3d999eec4087b76a370e02173444482cff5c1dd0..f5344cfe303c4fd09f508954cb703f8b069e80c4 100644 (file)
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -112,7 +112,8 @@
 struct exar8250;
 
 struct exar8250_platform {
-       int (*rs485_config)(struct uart_port *, struct serial_rs485 *);
+       int (*rs485_config)(struct uart_port *port, struct ktermios *termios,
+                           struct serial_rs485 *rs485);
        const struct serial_rs485 *rs485_supported;
        int (*register_gpio)(struct pci_dev *, struct uart_8250_port *);
        void (*unregister_gpio)(struct uart_8250_port *);
@@ -409,7 +410,7 @@ static void xr17v35x_unregister_gpio(struct uart_8250_port *port)
        port->port.private_data = NULL;
 }
 
-static int generic_rs485_config(struct uart_port *port,
+static int generic_rs485_config(struct uart_port *port, struct ktermios *termios,
                                struct serial_rs485 *rs485)
 {
        bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
@@ -441,7 +442,7 @@ static const struct exar8250_platform exar8250_default_platform = {
        .rs485_supported = &generic_rs485_supported,
 };
 
-static int iot2040_rs485_config(struct uart_port *port,
+static int iot2040_rs485_config(struct uart_port *port, struct ktermios *termios,
                                struct serial_rs485 *rs485)
 {
        bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
@@ -471,7 +472,7 @@ static int iot2040_rs485_config(struct uart_port *port,
        value |= mode;
        writeb(value, p + UART_EXAR_MPIOLVL_7_0);
 
-       return generic_rs485_config(port, rs485);
+       return generic_rs485_config(port, termios, rs485);
 }
 
 static const struct serial_rs485 iot2040_rs485_supported = {

diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index 1fb86c73786c71d90033b3f16b2f43e89916dbd0..eea693f5b57713d06a57391ecfa7873da90d8e96 100644 (file)
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -191,7 +191,7 @@ static int fintek_8250_get_ldn_range(struct fintek_8250 *pdata, int *min,
        return -ENODEV;
 }
 
-static int fintek_8250_rs485_config(struct uart_port *port,
+static int fintek_8250_rs485_config(struct uart_port *port, struct ktermios *termios,
                              struct serial_rs485 *rs485)
 {
        uint8_t config = 0;

diff --git a/drivers/tty/serial/8250/8250_lpc18xx.c b/drivers/tty/serial/8250/8250_lpc18xx.c
index 3a1cb51cbc919a1acb9ae0a04b600cf578f0618b..d7cb3bb5206978826861305c2c9ea6bed34586da 100644 (file)
--- a/drivers/tty/serial/8250/8250_lpc18xx.c
+++ b/drivers/tty/serial/8250/8250_lpc18xx.c
@@ -32,7 +32,7 @@ struct lpc18xx_uart_data {
        int line;
 };
 
-static int lpc18xx_rs485_config(struct uart_port *port,
+static int lpc18xx_rs485_config(struct uart_port *port, struct ktermios *termios,
                                struct serial_rs485 *rs485)
 {
        struct uart_8250_port *up = up_to_u8250p(port);

diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index b6d71268aa7da00cfe31bb2d6df04e6044da9eb6..d31d2350a9dbfcbdcd46bf83a508d77a3999e872 100644 (file)
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1553,7 +1553,7 @@ pci_brcm_trumanage_setup(struct serial_private *priv,
 #define FINTEK_RTS_INVERT              BIT(5)
 
 /* We should do proper H/W transceiver setting before change to RS485 mode */
-static int pci_fintek_rs485_config(struct uart_port *port,
+static int pci_fintek_rs485_config(struct uart_port *port, struct ktermios *termios,
                               struct serial_rs485 *rs485)
 {
        struct pci_dev *pci_dev = to_pci_dev(port->dev);

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index c8ae0e8376d489ff94e3759801a6624556fd73ae..d4337d8346c8edc50e82912aa406e42ee11511e7 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -664,7 +664,8 @@ EXPORT_SYMBOL_GPL(serial8250_em485_supported);
  * if the uart is incapable of driving RTS as a Transmit Enable signal in
  * hardware, relying on software emulation instead.
  */
-int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485)
+int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
+                           struct serial_rs485 *rs485)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
 

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index eccd66625d259c1a89b14cc22feb74ef56b32e7d..c8f52945a4aafe72897568591f9312a04b2562e1 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2197,7 +2197,7 @@ static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
        return ret;
 }
 
-static int pl011_rs485_config(struct uart_port *port,
+static int pl011_rs485_config(struct uart_port *port, struct ktermios *termios,
                              struct serial_rs485 *rs485)
 {
        struct uart_amba_port *uap =

diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index ab2c5b2a1ce8225af6f86b7b130409ceb045d9f5..b73ce13683dbc06f39e5d83f9e2d4998b11aaf5c 100644 (file)
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -580,7 +580,7 @@ static const struct uart_ops ar933x_uart_ops = {
        .verify_port    = ar933x_uart_verify_port,
 };
 
-static int ar933x_config_rs485(struct uart_port *port,
+static int ar933x_config_rs485(struct uart_port *port, struct ktermios *termios,
                                struct serial_rs485 *rs485conf)
 {
        struct ar933x_uart_port *up =

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 3a94c2bdda72fb7fc683bc97f25efc43534da233..bc600467958583ff29779898a552a60ca3a23ef3 100644 (file)
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -283,7 +283,7 @@ static void atmel_tasklet_schedule(struct atmel_uart_port *atmel_port,
 }
 
 /* Enable or disable the rs485 support */
-static int atmel_config_rs485(struct uart_port *port,
+static int atmel_config_rs485(struct uart_port *port, struct ktermios *termios,
                              struct serial_rs485 *rs485conf)
 {
        struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index d35414cb3e4e0748ec95970843090e9006355732..8fe0494d4057bcc137cdce2809c8d25d535c36dd 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1355,7 +1355,7 @@ static void lpuart_dma_rx_free(struct uart_port *port)
        sport->dma_rx_cookie = -EINVAL;
 }
 
-static int lpuart_config_rs485(struct uart_port *port,
+static int lpuart_config_rs485(struct uart_port *port, struct ktermios *termios,
                        struct serial_rs485 *rs485)
 {
        struct lpuart_port *sport = container_of(port,
@@ -1385,7 +1385,7 @@ static int lpuart_config_rs485(struct uart_port *port,
        return 0;
 }
 
-static int lpuart32_config_rs485(struct uart_port *port,
+static int lpuart32_config_rs485(struct uart_port *port, struct ktermios *termios,
                        struct serial_rs485 *rs485)
 {
        struct lpuart_port *sport = container_of(port,

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index f4edde54175f6ac4fbb4b29b3ad85cb63db1b3b2..3457006cea3f876dfdc0fdc40220daed86ef3638 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1907,7 +1907,7 @@ static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
 #endif
 
 /* called with port.lock taken and irqs off or from .probe without locking */
-static int imx_uart_rs485_config(struct uart_port *port,
+static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termios,
                                 struct serial_rs485 *rs485conf)
 {
        struct imx_port *sport = (struct imx_port *)port;

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 4915a786e31585b0f58e696299fa96a91ac6a7f7..e162bfb44080e9ffa985f462d9c08f907ef3fd6c 100644 (file)
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1036,7 +1036,7 @@ static void max310x_rs_proc(struct work_struct *ws)
                        MAX310X_MODE2_ECHOSUPR_BIT, mode2);
 }
 
-static int max310x_rs485_config(struct uart_port *port,
+static int max310x_rs485_config(struct uart_port *port, struct ktermios *termios,
                                struct serial_rs485 *rs485)
 {
        struct max310x_one *one = to_max310x_port(port);

diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
index 036f178e3d6622e69c90f8022bc2f78a47f29acc..73c5287b8e5e0918a89ba14d7d6bd387364c5664 100644 (file)
--- a/drivers/tty/serial/mcf.c
+++ b/drivers/tty/serial/mcf.c
@@ -431,7 +431,8 @@ static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
 /****************************************************************************/
 
 /* Enable or disable the RS485 support */
-static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
+static int mcf_config_rs485(struct uart_port *port, struct ktermios *termios,
+                           struct serial_rs485 *rs485)
 {
        unsigned char mr1, mr2;
 

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 52cb1a68b053458525ce24349007ade781793c1c..196bae704f859dc83f543722a681252535ed14e8 100644 (file)
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1324,7 +1324,8 @@ static inline void serial_omap_add_console_port(struct uart_omap_port *up)
 
 /* Enable or disable the rs485 support */
 static int
-serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
+serial_omap_config_rs485(struct uart_port *port, struct ktermios *termios,
+                        struct serial_rs485 *rs485)
 {
        struct uart_omap_port *up = to_uart_omap_port(port);
        unsigned int mode;

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 2ceecaa4a4780deac853e8e8330b340c23d1523f..8cb92a3b3fb8f2f1bbbf4864da815a8da6ba6b5b 100644 (file)
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1127,7 +1127,7 @@ static void sc16is7xx_set_termios(struct uart_port *port,
        spin_unlock_irqrestore(&port->lock, flags);
 }
 
-static int sc16is7xx_config_rs485(struct uart_port *port,
+static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
                                  struct serial_rs485 *rs485)
 {
        struct sc16is7xx_port *s = dev_get_drvdata(port->dev);

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 75ece750bedcb7f4c1ca116836adc462db027073..2529153c89791edc283a140e812aaaa1c984dfdb 100644 (file)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1353,7 +1353,7 @@ int uart_rs485_config(struct uart_port *port)
 
        uart_sanitize_serial_rs485(port, rs485);
 
-       ret = port->rs485_config(port, rs485);
+       ret = port->rs485_config(port, NULL, rs485);
        if (ret)
                memset(rs485, 0, sizeof(*rs485));
 
@@ -1377,7 +1377,7 @@ static int uart_get_rs485_config(struct uart_port *port,
        return 0;
 }
 
-static int uart_set_rs485_config(struct uart_port *port,
+static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
                         struct serial_rs485 __user *rs485_user)
 {
        struct serial_rs485 rs485;
@@ -1396,7 +1396,7 @@ static int uart_set_rs485_config(struct uart_port *port,
        uart_sanitize_serial_rs485(port, &rs485);
 
        spin_lock_irqsave(&port->lock, flags);
-       ret = port->rs485_config(port, &rs485);
+       ret = port->rs485_config(port, &tty->termios, &rs485);
        if (!ret)
                port->rs485 = rs485;
        spin_unlock_irqrestore(&port->lock, flags);
@@ -1505,6 +1505,10 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
        if (ret != -ENOIOCTLCMD)
                goto out;
 
+       /* rs485_config requires more locking than others */
+       if (cmd == TIOCGRS485)
+               down_write(&tty->termios_rwsem);
+
        mutex_lock(&port->mutex);
        uport = uart_port_check(state);
 
@@ -1528,7 +1532,7 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
                break;
 
        case TIOCSRS485:
-               ret = uart_set_rs485_config(uport, uarg);
+               ret = uart_set_rs485_config(tty, uport, uarg);
                break;
 
        case TIOCSISO7816:
@@ -1545,6 +1549,8 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
        }
 out_up:
        mutex_unlock(&port->mutex);
+       if (cmd == TIOCGRS485)
+               up_write(&tty->termios_rwsem);
 out:
        return ret;
 }

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index db3dd9731ee1e2828809d6bbbd2412655b562682..13992e64a7df907a4dbaa23cebbf49e9861fcd53 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -97,7 +97,7 @@ static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
        *cr1 |= rs485_deat_dedt;
 }
 
-static int stm32_usart_config_rs485(struct uart_port *port,
+static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *termios,
                                    struct serial_rs485 *rs485conf)
 {
        struct stm32_port *stm32_port = to_stm32_port(port);

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index faaf2372c60dbc2e1b8d32bc6a701d10beedce53..b7b86ee3cb125a2ab3c9d35531d70b5e9bec7c63 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -133,6 +133,7 @@ struct uart_port {
                                      unsigned int old);
        void                    (*handle_break)(struct uart_port *);
        int                     (*rs485_config)(struct uart_port *,
+                                               struct ktermios *termios,
                                                struct serial_rs485 *rs485);
        int                     (*iso7816_config)(struct uart_port *,
                                                  struct serial_iso7816 *iso7816);