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tty: serial: samsung_tty: do not abuse the struct uart_port unused fi…
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…elds

The samsung_tty driver was trying to abuse the struct uart_port by using
two "empty" bytes for its own use.  That's not ok, and was found by
removing those fields from the structure.

Move the variables into the port-specific structure, which is where
everything else for this port already is.  There is no space wasted here
as there was an empty "hole" in the structure already for these bytes.

Cc: Kukjin Kim <kgene@kernel.org>
Cc: Hyunki Koo <kkoos00@naver.com>
Cc: HYUN-KI KOO <hyunki00.koo@samsung.com>
Cc: Shinbeom Choi <sbeom.choi@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20191217140232.GA3489190@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Greg Kroah-Hartman committed Dec 17, 2019
1 parent 7e5ed9f commit 8336240
Showing 1 changed file with 23 additions and 23 deletions.
46 changes: 23 additions & 23 deletions drivers/tty/serial/samsung_tty.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,10 +56,6 @@
#define S3C24XX_TX_DMA 2
#define S3C24XX_RX_PIO 1
#define S3C24XX_RX_DMA 2
/* macros to change one thing to another */

#define tx_enabled(port) ((port)->unused[0])
#define rx_enabled(port) ((port)->unused[1])

/* flag to ignore all characters coming in */
#define RXSTAT_DUMMY_READ (0x10000000)
Expand Down Expand Up @@ -123,6 +119,8 @@ struct s3c24xx_uart_dma {
struct s3c24xx_uart_port {
unsigned char rx_claimed;
unsigned char tx_claimed;
unsigned char rx_enabled;
unsigned char tx_enabled;
unsigned int pm_level;
unsigned long baudclk_rate;
unsigned int min_dma_size;
Expand Down Expand Up @@ -223,6 +221,7 @@ static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)

static void s3c24xx_serial_rx_enable(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
unsigned long flags;
unsigned int ucon, ufcon;
int count = 10000;
Expand All @@ -240,12 +239,13 @@ static void s3c24xx_serial_rx_enable(struct uart_port *port)
ucon |= S3C2410_UCON_RXIRQMODE;
wr_regl(port, S3C2410_UCON, ucon);

rx_enabled(port) = 1;
ourport->rx_enabled = 1;
spin_unlock_irqrestore(&port->lock, flags);
}

static void s3c24xx_serial_rx_disable(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
unsigned long flags;
unsigned int ucon;

Expand All @@ -255,7 +255,7 @@ static void s3c24xx_serial_rx_disable(struct uart_port *port)
ucon &= ~S3C2410_UCON_RXIRQMODE;
wr_regl(port, S3C2410_UCON, ucon);

rx_enabled(port) = 0;
ourport->rx_enabled = 0;
spin_unlock_irqrestore(&port->lock, flags);
}

Expand All @@ -267,7 +267,7 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port)
struct dma_tx_state state;
int count;

if (!tx_enabled(port))
if (!ourport->tx_enabled)
return;

if (s3c24xx_serial_has_interrupt_mask(port))
Expand All @@ -287,7 +287,7 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port)
port->icount.tx += count;
}

tx_enabled(port) = 0;
ourport->tx_enabled = 0;
ourport->tx_in_progress = 0;

if (port->flags & UPF_CONS_FLOW)
Expand Down Expand Up @@ -445,11 +445,11 @@ static void s3c24xx_serial_start_tx(struct uart_port *port)
struct s3c24xx_uart_port *ourport = to_ourport(port);
struct circ_buf *xmit = &port->state->xmit;

if (!tx_enabled(port)) {
if (!ourport->tx_enabled) {
if (port->flags & UPF_CONS_FLOW)
s3c24xx_serial_rx_disable(port);

tx_enabled(port) = 1;
ourport->tx_enabled = 1;
if (!ourport->dma || !ourport->dma->tx_chan)
s3c24xx_serial_start_tx_pio(ourport);
}
Expand Down Expand Up @@ -494,14 +494,14 @@ static void s3c24xx_serial_stop_rx(struct uart_port *port)
enum dma_status dma_status;
unsigned int received;

if (rx_enabled(port)) {
if (ourport->rx_enabled) {
dev_dbg(port->dev, "stopping rx\n");
if (s3c24xx_serial_has_interrupt_mask(port))
s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
S3C64XX_UINTM);
else
disable_irq_nosync(ourport->rx_irq);
rx_enabled(port) = 0;
ourport->rx_enabled = 0;
}
if (dma && dma->rx_chan) {
dmaengine_pause(dma->tx_chan);
Expand Down Expand Up @@ -723,17 +723,17 @@ static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
if (port->flags & UPF_CONS_FLOW) {
int txe = s3c24xx_serial_txempty_nofifo(port);

if (rx_enabled(port)) {
if (ourport->rx_enabled) {
if (!txe) {
rx_enabled(port) = 0;
ourport->rx_enabled = 0;
continue;
}
} else {
if (txe) {
ufcon = rd_regl(port, S3C2410_UFCON);
ufcon |= S3C2410_UFCON_RESETRX;
wr_regl(port, S3C2410_UFCON, ufcon);
rx_enabled(port) = 1;
ourport->rx_enabled = 1;
return;
}
continue;
Expand Down Expand Up @@ -1084,7 +1084,7 @@ static void s3c24xx_serial_shutdown(struct uart_port *port)
if (ourport->tx_claimed) {
if (!s3c24xx_serial_has_interrupt_mask(port))
free_irq(ourport->tx_irq, ourport);
tx_enabled(port) = 0;
ourport->tx_enabled = 0;
ourport->tx_claimed = 0;
ourport->tx_mode = 0;
}
Expand All @@ -1093,7 +1093,7 @@ static void s3c24xx_serial_shutdown(struct uart_port *port)
if (!s3c24xx_serial_has_interrupt_mask(port))
free_irq(ourport->rx_irq, ourport);
ourport->rx_claimed = 0;
rx_enabled(port) = 0;
ourport->rx_enabled = 0;
}

/* Clear pending interrupts and mask all interrupts */
Expand All @@ -1115,7 +1115,7 @@ static int s3c24xx_serial_startup(struct uart_port *port)
struct s3c24xx_uart_port *ourport = to_ourport(port);
int ret;

rx_enabled(port) = 1;
ourport->rx_enabled = 1;

ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
s3c24xx_serial_portname(port), ourport);
Expand All @@ -1129,7 +1129,7 @@ static int s3c24xx_serial_startup(struct uart_port *port)

dev_dbg(port->dev, "requesting tx irq...\n");

tx_enabled(port) = 1;
ourport->tx_enabled = 1;

ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
s3c24xx_serial_portname(port), ourport);
Expand Down Expand Up @@ -1176,9 +1176,9 @@ static int s3c64xx_serial_startup(struct uart_port *port)
}

/* For compatibility with s3c24xx Soc's */
rx_enabled(port) = 1;
ourport->rx_enabled = 1;
ourport->rx_claimed = 1;
tx_enabled(port) = 0;
ourport->tx_enabled = 0;
ourport->tx_claimed = 1;

spin_lock_irqsave(&port->lock, flags);
Expand Down Expand Up @@ -2112,9 +2112,9 @@ static int s3c24xx_serial_resume_noirq(struct device *dev)
if (s3c24xx_serial_has_interrupt_mask(port)) {
unsigned int uintm = 0xf;

if (tx_enabled(port))
if (ourport->tx_enabled)
uintm &= ~S3C64XX_UINTM_TXD_MSK;
if (rx_enabled(port))
if (ourport->rx_enabled)
uintm &= ~S3C64XX_UINTM_RXD_MSK;
clk_prepare_enable(ourport->clk);
if (!IS_ERR(ourport->baudclk))
Expand Down

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