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

[Laurent Vivier <Laurent@Vivier.EU>]

Le 06/09/2013 18:17, Peter Maydell a écrit :
> On 30 August 2013 00:46, Laurent Vivier <laurent@vivier.eu> 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