Re: V3 [PATCH] Set tunable value as well as min/max values

[Siddhesh Poyarekar <siddhesh@sourceware.org>]

On 29/09/20 09:30, H.J. Lu via Libc-alpha wrote:
> Here is the updated patch with TUNABLE_SET_WITH_BOUNDS.
> 

> @@ -101,12 +101,19 @@ get_next_env (char **envp, char **name, size_t *namelen, char **val,
>  })
>  
>  static void
> -do_tunable_update_val (tunable_t *cur, const void *valp)
> +do_tunable_update_val (tunable_t *cur, const void *valp,
> +		       const void *minp, const void *maxp)
>  {
>    uint64_t val;
>  
>    if (cur->type.type_code != TUNABLE_TYPE_STRING)
> -    val = *((int64_t *) valp);
> +    {
> +      val = *((int64_t *) valp);
> +      if (minp)
> +	cur->type.min = *((int64_t *) minp);
> +      if (maxp)
> +	cur->type.max = *((int64_t *) maxp);
> +    }
>  
>    switch (cur->type.type_code)
>      {
> @@ -153,15 +160,15 @@ tunable_initialize (tunable_t *cur, con

There should be a check here to ensure that the bounds do not exceed
statically set bounds.  That is:

    if (minp != NULL && cur->type.min < *((int64_t *) minp))
      cur->type.min = *((int64_t *) minp);
    if (maxp != NULL && cur->type.max > *((int64_t *) maxp))
      cur->type.max = *((int64_t *) maxp);

Siddhesh