Re: [Qemu-devel] [PATCH] linux-user: Define AT_RANDOM to support target dynamic linkers that do ASLR

[Laurent Alfonsi]

> >          unsigned char k_rand_bytes[16];
> >          elf_addr_t __user *u_rand_bytes;
> > ...
> >          /*
> >           * Generate 16 random bytes for userspace PRNG seeding.
> >           */
> >          get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
> >          u_rand_bytes = (elf_addr_t __user *)
> >                         STACK_ALLOC(p, sizeof(k_rand_bytes));
> >          if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
> >                  return -EFAULT;
> > ...
> >          NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
> It's clearer to me now, thanks.
It is fine with me, I also understand better now.
And this now brings me to another point : In that case, it might have 
sense to also add the auxv AT_RANDOM_SIZE.
    http://sources.redhat.com/ml/libc-alpha/2008-10/msg00016.html

> > I suggest at minimum a command-line argument to force a
> > particular AT_RANDOM value, for repeatability.
Yep, I agree.

Laurent.