Re: [PATCH 1/4] xen/dmalloc: Introduce dmalloc() APIs

[Jan Beulich <jbeulich@xxxxxxxx>]

On 23.12.2020 17:34, Andrew Cooper wrote:
> --- /dev/null
> +++ b/xen/common/dmalloc.c
> @@ -0,0 +1,19 @@
> +#include <xen/dmalloc.h>
> +#include <xen/sched.h>
> +#include <xen/xmalloc.h>
> +
> +void dfree(struct domain *d, void *ptr)
> +{
> +    atomic_dec(&d->dalloc_heap);
> +    xfree(ptr);
> +}
> +
> +void *_dzalloc(struct domain *d, size_t size, size_t align)
> +{
> +    void *ptr = _xmalloc(size, align);
> +
> +    if ( ptr )
> +        atomic_inc(&d->dalloc_heap);

While this is properly conditional, the freeing side also needs to
tolerate NULL coming in (noticed only while looking at patch 2).
I also wonder whether ZERO_BLOCK_PTR wants special casing.

Jan