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.

2 files changed, 37 insertions, 10 deletions

diff --git a/usr.bin/vmstat/Makefile b/usr.bin/vmstat/Makefile
index 6ee77cedea3..2f5ce1caca2 100644
--- a/usr.bin/vmstat/Makefile
+++ b/usr.bin/vmstat/Makefile
@@ -1,7 +1,8 @@
-#	$OpenBSD: Makefile,v 1.8 2007/12/15 03:43:41 deraadt Exp $
+#	$OpenBSD: Makefile,v 1.9 2014/07/02 00:12:34 dlg Exp $
 
 PROG=	vmstat
 
+CPPFLAGS+= -D_LIBKVM
 SRCS=	dkstats.c vmstat.c
 MAN=	vmstat.8
 DPADD=	${LIBKVM}
diff --git a/usr.bin/vmstat/vmstat.c b/usr.bin/vmstat/vmstat.c
index 9b798eb7998..d72aae4b373 100644
--- a/usr.bin/vmstat/vmstat.c
+++ b/usr.bin/vmstat/vmstat.c
@@ -1,5 +1,5 @@
 /*	$NetBSD: vmstat.c,v 1.29.4.1 1996/06/05 00:21:05 cgd Exp $	*/
-/*	$OpenBSD: vmstat.c,v 1.128 2014/04/08 14:04:11 mpi Exp $	*/
+/*	$OpenBSD: vmstat.c,v 1.129 2014/07/02 00:12:34 dlg Exp $	*/
 
 /*
  * Copyright (c) 1980, 1986, 1991, 1993
@@ -887,7 +887,7 @@ domem(void)
 }
 
 static void
-print_pool(struct pool *pp, char *name)
+print_pool(struct kinfo_pool *pp, char *name)
 {
 	static int first = 1;
 	char maxp[32];
@@ -968,7 +968,7 @@ dopool_sysctl(void)
 {
 	int mib[4], npools, i;
 	long total = 0, inuse = 0;
-	struct pool pool;
+	struct kinfo_pool pool;
 	size_t size;
 
 	mib[0] = CTL_KERN;
@@ -987,7 +987,7 @@ dopool_sysctl(void)
 		mib[1] = KERN_POOL;
 		mib[2] = KERN_POOL_POOL;
 		mib[3] = i;
-		size = sizeof(struct pool);
+		size = sizeof(pool);
 		if (sysctl(mib, 4, &pool, &size, NULL, 0) < 0) {
 			if (errno == ENOENT)
 				continue;
@@ -1004,7 +1004,7 @@ dopool_sysctl(void)
 		print_pool(&pool, name);
 
 		inuse += (pool.pr_nget - pool.pr_nput) * pool.pr_size;
-		total += pool.pr_npages * getpagesize();	/* XXX */
+		total += pool.pr_npages * pool.pr_pgsize;
 	}
 
 	inuse /= 1024;
@@ -1018,6 +1018,8 @@ dopool_kvm(void)
 {
 	SIMPLEQ_HEAD(,pool) pool_head;
 	struct pool pool, *pp = &pool;
+	struct pool_allocator palloc;
+	struct kinfo_pool pi;
 	long total = 0, inuse = 0;
 	u_long addr;
 
@@ -1039,13 +1041,37 @@ dopool_kvm(void)
 			    kvm_geterr(kd));
 			exit(1);
 		}
+		if (kvm_read(kd, (u_long)pp->pr_alloc,
+		    &palloc, sizeof(palloc)) < 0) {
+			(void)fprintf(stderr,
+			    "vmstat: pool allocator trashed: %s\n",
+			    kvm_geterr(kd));
+			exit(1);
+		}
 
 		name[31] = '\0';
 
-		print_pool(pp, name);
-
-		inuse += (pp->pr_nget - pp->pr_nput) * pp->pr_size;
-		total += pp->pr_npages * getpagesize();	/* XXX */
+		memset(&pi, 0, sizeof(pi));
+		pi.pr_size = pp->pr_size;
+		pi.pr_pgsize = palloc.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;
+
+		print_pool(&pi, name);
+
+		inuse += (pi.pr_nget - pi.pr_nput) * pi.pr_size;
+		total += pi.pr_npages * pi.pr_pgsize;
 
 		addr = (u_long)SIMPLEQ_NEXT(pp, pr_poollist);
 	}