Re: [Qemu-devel] [PATCH 5/6] linux-user: add support of binfmt_misc 'O' flag

[Laurent Vivier]

Le 06/09/2013 18:17, Peter Maydell a écrit :
> On 30 August 2013 00:46, Laurent Vivier <address@hidden> wrote:
> > The binfmt_misc module can calculate the credentials and security
> > token according to the binary instead of to the interpreter if the
> > 'C' flag is enabled.
> >
> > To be able to execute non-readable binaries, this flag implies 'O'
> > flag. When 'O' flag is enabled, bintfmt_misc opens the file for
> > reading and pass the file descriptor to the interpreter.
> >
> > References:
> > linux/Documentation/binfmt_misc.txt          ['O' and 'C' description]
> > linux/fs/binfmt_misc.c linux/fs/binfmt_elf.c [ AT_EXECFD usage ]
> > +static int get_execfd(char **envp)
> > +{
> > +    typedef struct {
> > +        long a_type;
> > +        long a_val;
> > +    } auxv_t;
> > +    auxv_t *auxv;
> > +
> > +    while (*envp++ != NULL) {
> > +        ;
> > +    }
> > +
> > +    for (auxv = (auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
> > +        if (auxv->a_type == AT_EXECFD) {
> > +            return auxv->a_val;
> > +        }
> > +    }
> > +    return -1;
> > +}
> This looks OK in principle, but this is going to clash
> with RTH's auxval related patchset
> http://patchwork.ozlabs.org/patch/268006/
>
> so some coordination might be a good idea.
Yes, thank you to point this out.

What is the state of this patches series ?

Richard, could you add this as patch #7 ?
I think replacing "get_execfd(envp)" by "qemu_getauxval(AT_EXECFD)" 
should be enough.
Do you want I manage this ?

Regards,
Laurent