Re: [PATCH] target/arm/arm-semi: Don't let the guest close stdin/stdout/stderr

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

Peter Maydell <peter.maydell@linaro.org> writes:

> The guest can use the semihosting API to open a handle
> corresponding to QEMU's own stdin, stdout, or stderr.
> When the guest closes this handle, we should not
> close the underlying host stdin/stdout/stderr
> the way we would do if the handle corresponded to
> a host fd we'd opened on behalf of the guest in SYS_OPEN.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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

> ---
>  target/arm/arm-semi.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
> index 788fe61b51a..8718fd01948 100644
> --- a/target/arm/arm-semi.c
> +++ b/target/arm/arm-semi.c
> @@ -403,6 +403,15 @@ static uint32_t host_closefn(ARMCPU *cpu, GuestFD *gf)
>  {
>      CPUARMState *env = &cpu->env;
>  
> +    /*
> +     * Only close the underlying host fd if it's one we opened on behalf
> +     * of the guest in SYS_OPEN.
> +     */
> +    if (gf->hostfd == STDIN_FILENO ||
> +        gf->hostfd == STDOUT_FILENO ||
> +        gf->hostfd == STDERR_FILENO) {
> +        return 0;
> +    }
>      return set_swi_errno(env, close(gf->hostfd));
>  }


-- 
Alex Bennée