[BUG] poweroff command in ./u-boot -T -l causes SIG_SEGV

[Simon Glass]

Hi Heinrich,

On Sat, 22 Oct 2022 at 06:19, Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
>
> > Date: Sat, 22 Oct 2022 11:14:34 +0200
> > From: Heinrich Schuchardt <xypron.glpk at gmx.de>
> >
> > Hello Simon,
> >
> > when running ./u-boot -T -l and issuing the poweroff command a crash occurs:
> >
> > os_exit() results in std::ostream::flush() calling U-Boot's fflush with
> > file = -138447008 (or any other negative number)
> >
> > Man fflush shows the following definition:
> >
> >      int fflush(FILE *stream);
> >
> > U-Boot's fflush() is defined as
> >
> >      void fflush(int file);
> >
> > The pointer FILE *stream is truncated to int which may result in a
> > negative number when invoking U-Boot's fflush() but anyway we want
> > std::ostream::flush() to invoke glibc's fflush().
> >
> > Can we ensure correct linking or do we have to rename fflush()?
>
> Probably have to rename it.  The name is reserved by the ISO C
> standard, at least when building in a non-freestanding environment.
> And the sandbox stuff means that U-Boot isn't always compiled in a
> free-standing environment.
>
> I do wonder though how you end up building the sandbox with a C++
> compiler.  There is some logic in the build system (inherited from the
> Linux kernel?) to build host tools with C++.  But I'd hope the sandbox
> doesn't use that.

Yes, renaming it seems OK to me.

Regards,
Simon