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

[Philippe Mathieu-Daudé]

On 1/24/20 8:57 PM, Alex Bennée wrote:
> Peter Maydell <address@hidden> 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 <address@hidden>
>
> Reviewed-by: Alex Bennée <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> > ---
> >   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));
> >   }