Re: [RFC][PATCH 04/20] pspace: Allow multiple instaces of the process id namespace

[William Lee Irwin III <wli@holomorphy.com>]

On Mon, Feb 06, 2006 at 12:34:08PM -0700, Eric W. Biederman wrote:
> -#define mk_pid(map, off)	(((map) - pidmap_array)*BITS_PER_PAGE + (off))
> +#define mk_pid(map, off)	(((map) - pspace->pidmap)*BITS_PER_PAGE + (off))
>  #define find_next_offset(map, off)					\

mk_pid() should be:

#define mk_pid(pspace, map, off)	\
			(((map) - (pspace)->pidmap)*BITS_PER_PAGE + (off))

or otherwise made an inline; pscape escaping like this shouldn't happen.


On Mon, Feb 06, 2006 at 12:34:08PM -0700, Eric W. Biederman wrote:
> +static struct pspace *new_pspace(struct task_struct *leader)
> +{
> +	struct pspace *pspace, *parent;
> +	int i;
> +	size_t len;
> +	parent = leader->pspace;
> +	len = strlen(parent->name) + 10;
> +	pspace = kzalloc(sizeof(struct pspace) + len, GFP_KERNEL);
> +	if (!pspace)
> +		return NULL;
> +	atomic_set(&pspace->count, 1);
> +	pspace->flags        = 0;
> +	pspace->nr_threads   = 0;
> +	pspace->nr_processes = 0;
> +	pspace->last_pid     = 0;
> +	pspace->min          = RESERVED_PIDS;
> +	pspace->max          = PID_MAX_DEFAULT;
> +	for (i = 0; i < PIDMAP_ENTRIES; i++) {
> +		atomic_set(&pspace->pidmap[i].nr_free,  BITS_PER_PAGE);
> +		pspace->pidmap[i].page = NULL;
> +	}
> +	attach_any_pid(&pspace->child_reaper, leader, PIDTYPE_PID, 
> +			parent, leader->wid);
> +	leader->pspace->nr_processes++;
> +	snprintf(pspace->name, len + 1, "%s/%d", parent->name, leader->wid);
> +
> +	return pspace;
> +}

kzalloc() followed by zeroing ->flags et al by hand is redundant.


-- wli