Re: [PATCH v3 10/49] semihosting: Clean up common_semi_flen_cb

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> Do not read from the gdb struct stat buffer if the callback is
> reporting an error. Use common_semi_cb to finish returning results.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  semihosting/arm-compat-semi.c | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
> index 88e1c286ba..8792180974 100644
> --- a/semihosting/arm-compat-semi.c
> +++ b/semihosting/arm-compat-semi.c
> @@ -346,15 +346,17 @@ static target_ulong common_semi_flen_buf(CPUState *cs)
>  static void
>  common_semi_flen_cb(CPUState *cs, target_ulong ret, target_ulong err)
>  {
> -    /* The size is always stored in big-endian order, extract
> -       the value. We assume the size always fit in 32 bits.  */
> -    uint32_t size;
> -    cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) + 32,
> -                        (uint8_t *)&size, 4, 0);
> -    size = be32_to_cpu(size);
> -    common_semi_set_ret(cs, size);
> -    errno = err;
> -    set_swi_errno(cs, -1);
> +    if (!err) {
> +        /*
> +         * The size is always stored in big-endian order, extract
> +         * the value. We assume the size always fit in 32 bits.
> +         */
> +        uint32_t size;
> +        cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) + 32,
> +                            (uint8_t *)&size, 4, 0);

I did a double take but compared to the actual code it calls I guess
its fine. Technically I think: 

        cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) + 32,
                            (void *) &size, sizeof(size), 0);

might be slightly cleaner but whatever:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


> +        ret = be32_to_cpu(size);
> +    }
> +    common_semi_cb(cs, ret, err);
>  }
>  
>  static int common_semi_open_guestfd;


-- 
Alex Bennée