diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2015-03-09 14:05:00 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-26 22:21:08 +0100 |
| commit | 509cb7dc07cc03c28c7995a9213a605c04675a58 (patch) | |
| tree | ed7b191357a6f1424d84a2daf1f0429db63b9c62 /drivers/tty | |
| parent | 72a33aad476f9d4b1210dbf434f53eeea84909ab (diff) | |
serial: 8250: Validate reg addr for Au1x00/RT288x i/o accessors
Au1x00/RT2800+ hardware has an alternate register layout which is
remapped with lookup tables by the au_serial_in()/out() i/o accessors.
However, the h/w does not support the complete 8250 register set, and
accesses to unmapped registers cause out-of-bounds lookups. Further,
because the lookup tables are defined by designated initializers, the
tables may contain unmapped entries (although the current tables do not).
Declare fixed-size lookup tables with contiguous initialization for
the complete 8250 register map; unmapped registers are initialized to -1.
Validate the register index (ie., 'offset') is in the range [0, table size).
Return fixed value for unmapped register reads and ignore unmapped register
writes.
Reported-by: Mason <slash.tmp@free.fr>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 48 |
1 files changed, 30 insertions, 18 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index b9f452fcb1a5..0a8f11b69e68 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -358,34 +358,46 @@ static void default_serial_dl_write(struct uart_8250_port *up, int value) #if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X) /* Au1x00/RT288x UART hardware has a weird register layout */ -static const u8 au_io_in_map[] = { - [UART_RX] = 0, - [UART_IER] = 2, - [UART_IIR] = 3, - [UART_LCR] = 5, - [UART_MCR] = 6, - [UART_LSR] = 7, - [UART_MSR] = 8, +static const s8 au_io_in_map[8] = { + 0, /* UART_RX */ + 2, /* UART_IER */ + 3, /* UART_IIR */ + 5, /* UART_LCR */ + 6, /* UART_MCR */ + 7, /* UART_LSR */ + 8, /* UART_MSR */ + -1, /* UART_SCR (unmapped) */ }; -static const u8 au_io_out_map[] = { - [UART_TX] = 1, - [UART_IER] = 2, - [UART_FCR] = 4, - [UART_LCR] = 5, - [UART_MCR] = 6, +static const s8 au_io_out_map[8] = { + 1, /* UART_TX */ + 2, /* UART_IER */ + 4, /* UART_FCR */ + 5, /* UART_LCR */ + 6, /* UART_MCR */ + -1, /* UART_LSR (unmapped) */ + -1, /* UART_MSR (unmapped) */ + -1, /* UART_SCR (unmapped) */ }; static unsigned int au_serial_in(struct uart_port *p, int offset) { - offset = au_io_in_map[offset] << p->regshift; - return __raw_readl(p->membase + offset); + if (offset >= ARRAY_SIZE(au_io_in_map)) + return UINT_MAX; + offset = au_io_in_map[offset]; + if (offset < 0) + return UINT_MAX; + return __raw_readl(p->membase + (offset << p->regshift)); } static void au_serial_out(struct uart_port *p, int offset, int value) { - offset = au_io_out_map[offset] << p->regshift; - __raw_writel(value, p->membase + offset); + if (offset >= ARRAY_SIZE(au_io_out_map)) + return; + offset = au_io_out_map[offset]; + if (offset < 0) + return; + __raw_writel(value, p->membase + (offset << p->regshift)); } /* Au1x00 haven't got a standard divisor latch */ |