Re: CVS commit: src/sys/dev/usb

[Jason Thorpe <thorpej%me.com@localhost>]

On Oct 23, 2026, at 8:33 AM, Taylor R Campbell <riastradh%NetBSD.org@localhost> wrote:

Maybe PR_ZERO should be an option to pool_cache_init rather than to
pool_cache_get?  (And pool_cache_get should assert that it is _not_
set.  Also pool_cache_init can assert that ctor/dtor is mutually
exclusive with PR_ZERO.)

Alternatively, there could be a magic constructor function value that could specify zero-on-allocate, since PR_ZERO and having a constructor are really mutually-exclusive.  

int

pool_cache_ctor_zero(void *arg __unused, void *obj __unused, int flags __unused)

{

    return 0;

}

…then in pool_cache_get_paddr(), before “object” is successfully returned:

    If (__predict_false(pc->pc_ctor == pool_cache_ctor_zero) {

        memset(object, 0, pp->pp_pool->pr_reqsize);

  }

Could even specify a magic destructor if you want to zero-on-free (e.g. security-sensitive uses).

-- thorpej