info about pools is currently given to userland by copying each

pools struct out. however, struct pool in the kernel contains lots
of things that userland probably isnt interested in, like actual
mutexes, and probably shouldnt get easy access to, like pointers
to kernel memory via all the lists/trees.

this implements a kinfo_pool structure that has only the data that
userland needs to know about. it cuts the sysctl code over to
building it from struct pool as required and copying that out
instead, and cuts userland over to only handling kinfo_pool.

the only problem with this is vmstat, which can read kernel images
via kvm, which needs some understanding of struct pool. to cope,
the struct pool definition is guarded by if defined(_KERNEL) ||
defined(_LIBKVM) as inspired by sysctl which needs to do the same
thing sometimes. struct pool itself is generally not visible to
userland though, which is good.

matthew@ suggested struct kinfo_pool instead of struct pool_info.
the kinfo prefix has precedent.
lots of people liked this.

1 files changed, 25 insertions, 10 deletions

diff --git a/sys/kern/subr_pool.c b/sys/kern/subr_pool.c
index 2dab25cbd76..b6fb87597e7 100644
--- a/sys/kern/subr_pool.c
+++ b/sys/kern/subr_pool.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_pool.c,v 1.128 2014/05/19 14:30:03 tedu Exp $	*/
+/*	$OpenBSD: subr_pool.c,v 1.129 2014/07/02 00:12:34 dlg Exp $	*/
 /*	$NetBSD: subr_pool.c,v 1.61 2001/09/26 07:14:56 chs Exp $	*/
 
 /*-
@@ -1422,7 +1422,8 @@ pool_walk(struct pool *pp, int full,
 int
 sysctl_dopool(int *name, u_int namelen, char *where, size_t *sizep)
 {
-	struct pool *pp, *foundpool = NULL;
+	struct kinfo_pool pi;
+	struct pool *pp;
 	size_t buflen = where != NULL ? *sizep : 0;
 	int npools = 0, s;
 	unsigned int lookfor;
@@ -1440,7 +1441,7 @@ sysctl_dopool(int *name, u_int namelen, char *where, size_t *sizep)
 		lookfor = name[1];
 		break;
 	case KERN_POOL_POOL:
-		if (namelen != 2 || buflen != sizeof(struct pool))
+		if (namelen != 2 || buflen != sizeof(pi))
 			return (EINVAL);
 		lookfor = name[1];
 		break;
@@ -1452,28 +1453,42 @@ sysctl_dopool(int *name, u_int namelen, char *where, size_t *sizep)
 
 	SIMPLEQ_FOREACH(pp, &pool_head, pr_poollist) {
 		npools++;
-		if (lookfor == pp->pr_serial) {
-			foundpool = pp;
+		if (lookfor == pp->pr_serial)
 			break;
-		}
 	}
 
 	splx(s);
 
-	if (*name != KERN_POOL_NPOOLS && foundpool == NULL)
+	if (*name != KERN_POOL_NPOOLS && pp == NULL)
 		return (ENOENT);
 
 	switch (*name) {
 	case KERN_POOL_NPOOLS:
 		return copyout(&npools, where, buflen);
 	case KERN_POOL_NAME:
-		len = strlen(foundpool->pr_wchan) + 1;
+		len = strlen(pp->pr_wchan) + 1;
 		if (*sizep < len)
 			return (ENOMEM);
 		*sizep = len;
-		return copyout(foundpool->pr_wchan, where, len);
+		return copyout(pp->pr_wchan, where, len);
 	case KERN_POOL_POOL:
-		return copyout(foundpool, where, buflen);
+		memset(&pi, 0, sizeof(pi));
+		pi.pr_size = pp->pr_size;
+		pi.pr_pgsize = pp->pr_alloc->pa_pagesz;
+		pi.pr_itemsperpage = pp->pr_itemsperpage;
+		pi.pr_minpages = pp->pr_minpages;
+		pi.pr_maxpages = pp->pr_maxpages;
+		pi.pr_hardlimit = pp->pr_hardlimit;
+		pi.pr_nout = pp->pr_nout;
+		pi.pr_nitems = pp->pr_nitems;
+		pi.pr_nget = pp->pr_nget;
+		pi.pr_nput = pp->pr_nput;
+		pi.pr_nfail = pp->pr_nfail;
+		pi.pr_npagealloc = pp->pr_npagealloc;
+		pi.pr_npagefree = pp->pr_npagefree;
+		pi.pr_hiwat = pp->pr_hiwat;
+		pi.pr_nidle = pp->pr_nidle;
+		return copyout(&pi, where, buflen);
 	}
 	/* NOTREACHED */
 	return (0); /* XXX - Stupid gcc */