Re: [Qemu-devel] [PATCH 4/6] linux-user: Initialize aarch64 pac keys

[Peter Maydell]

On Fri, 25 Jan 2019 at 22:57, Richard Henderson
<address@hidden> wrote:
>
> Initialize the keys to a non-zero value on process start.
>
> Signed-off-by: Richard Henderson <address@hidden>

> +static uint64_t arm_rand64(void)
> +{
> +    int shift = 64 - clz64(RAND_MAX);
> +    int i, n = 64 / shift + (64 % shift != 0);
> +    uint64_t ret = 0;
> +
> +    for (i = 0; i < n; i++) {
> +        ret = (ret << shift) | rand();
> +    }
> +    return ret;
> +}

I'm not a huge fan of the use of rand() here, but it's what
we're using to initialize AT_RANDOM in linux-user, so I guess
it's OK here. At some point we should investigate whether
there's something better we are guaranteed to have available,
I suppose. (Coverity gripes about use of rand().)

thanks
-- PMM