Re: [Qemu-devel] [PATCH v2] seccomp: add cacheflush to whitelist

[Andrew Jones]

On Mon, Nov 02, 2015 at 06:09:41PM +0000, Peter Maydell wrote:
> On 2 November 2015 at 17:56, Andrew Jones <address@hidden> wrote:
> > cacheflush is an arm-specific syscall that qemu built for arm
> > uses. Add it to the whitelist, but only if we're linking with
> > a recent enough libseccomp.
> >
> > Signed-off-by: Andrew Jones <address@hidden>
> > ---
> > v2: only add cacheflush if libseccomp supports it
> >
> >  qemu-seccomp.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/qemu-seccomp.c b/qemu-seccomp.c
> > index 80d034a8d5190..e76097e958779 100644
> > --- a/qemu-seccomp.c
> > +++ b/qemu-seccomp.c
> > @@ -16,6 +16,10 @@
> >  #include <seccomp.h>
> >  #include "sysemu/seccomp.h"
> >
> > +#if SCMP_VER_MAJOR >= 2 && SCMP_VER_MINOR >= 2 && SCMP_VER_MICRO >= 3
> > +#define HAVE_CACHEFLUSH
> > +#endif
> 
> This will claim that a hypothetical future version 3.0.0 does not
> have cacheflush...

Indeed. Sigh... In that case, how about just

#if defined(TARGET_ARM) || defined(TARGET_AARCH64)
    { SCMP_SYS(cacheflush), 240 },
#endif

Thanks,
drew

> 
> thanks
> -- PMM
>