Re: [PATCH] Blackfin: sync termios header changes with x86

[Arnd Bergmann <arnd@arndb.de>]

On Friday 12 June 2009, Mike Frysinger wrote:

> Arnd: if you don't mind, i'd rather merge this ... i can put it into my
> next batch of Blackfin changes for 2.6.31

I don't see how that helps, because:
 
>  #define TIOCMIWAIT	0x545C	/* wait for a change on serial input line(s) */
>  #define TIOCGICOUNT	0x545D	/* read serial port inline interrupt counts */
> -
> -#define FIOQSIZE	0x545E
> +#define TIOCGHAYESESP   0x545E  /* Get Hayes ESP configuration */
> +#define TIOCSHAYESESP   0x545F  /* Set Hayes ESP configuration */
> +#define FIOQSIZE	0x5460

This breaks existing applications using FIOQSIZE. You really shouldn't do that.

> diff --git a/arch/blackfin/include/asm/termbits.h b/arch/blackfin/include/asm/termbits.h
> index f37feb7..faa569f 100644
> --- a/arch/blackfin/include/asm/termbits.h
> +++ b/arch/blackfin/include/asm/termbits.h

This one only changes whitespace, what is the point?

> --- a/arch/blackfin/include/asm/termios.h
> +++ b/arch/blackfin/include/asm/termios.h

This change fixes one bug but not another:

> @@ -58,37 +60,55 @@ struct termio {
>  	*(unsigned short *) &(termios)->x = __tmp; \
>  }
>  
> -#define user_termio_to_kernel_termios(termios, termio) \
> -({ \
> -	SET_LOW_TERMIOS_BITS(termios, termio, c_iflag); \
> -	SET_LOW_TERMIOS_BITS(termios, termio, c_oflag); \
> -	SET_LOW_TERMIOS_BITS(termios, termio, c_cflag); \
> -	SET_LOW_TERMIOS_BITS(termios, termio, c_lflag); \
> -	copy_from_user((termios)->c_cc, (termio)->c_cc, NCC); \
> -})
> +static inline int user_termio_to_kernel_termios(struct ktermios *termios,
> +						struct termio __user *termio)
> +{
> +	SET_LOW_TERMIOS_BITS(termios, termio, c_iflag);
> +	SET_LOW_TERMIOS_BITS(termios, termio, c_oflag);
> +	SET_LOW_TERMIOS_BITS(termios, termio, c_cflag);
> +	SET_LOW_TERMIOS_BITS(termios, termio, c_lflag);
> +	get_user(termios->c_line, &termio->c_line);
> +	return copy_from_user(termios->c_cc, termio->c_cc, NCC);
> +}

You correctly read termios->c_line now, which was missing previously,
but you still don't check the return value of the get_user and
copy_from_user functions. The code also has a very ugly property
of working only on little-endian architectures (which includes
blackfin AFAICT) but should not serve as an example.

If you want a working version of this file, best copy it from avr32
or frv. Or just wait for the asm-generic version.

	Arnd <><