From cb50a739c3a726b5a1ff3b90472a4eb2bc86caff Mon Sep 17 00:00:00 2001
From: pooka <pooka@NetBSD.org>
Date: Fri, 26 Oct 2007 13:51:14 +0000
Subject: [PATCH] mmap stacks, makes it possible to align them

---
 lib/libpuffs/callcontext.c | 19 +++++++++++++------
 lib/libpuffs/puffs.c       | 18 +++++++++++++-----
 lib/libpuffs/puffs.h       |  4 ++--
 lib/libpuffs/puffs_priv.h  |  4 ++--
 4 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/lib/libpuffs/callcontext.c b/lib/libpuffs/callcontext.c
index e586698ac115..5a769bcb36d7 100644
--- a/lib/libpuffs/callcontext.c
+++ b/lib/libpuffs/callcontext.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: callcontext.c,v 1.10 2007/10/21 19:25:58 pooka Exp $	*/
+/*	$NetBSD: callcontext.c,v 1.11 2007/10/26 13:51:14 pooka Exp $	*/
 
 /*
  * Copyright (c) 2006 Antti Kantee.  All Rights Reserved.
@@ -27,10 +27,11 @@
 
 #include <sys/cdefs.h>
 #if !defined(lint)
-__RCSID("$NetBSD: callcontext.c,v 1.10 2007/10/21 19:25:58 pooka Exp $");
+__RCSID("$NetBSD: callcontext.c,v 1.11 2007/10/26 13:51:14 pooka Exp $");
 #endif /* !lint */
 
 #include <sys/types.h>
+#include <sys/mman.h>
 
 #include <assert.h>
 #include <errno.h>
@@ -127,7 +128,9 @@ struct puffs_cc *
 puffs_cc_create(struct puffs_usermount *pu)
 {
 	struct puffs_cc *volatile pcc;
+	size_t stacksize = 1<<pu->pu_cc_stackshift;
 	stack_t *st;
+	void *sp;
 
 	pcc = malloc(sizeof(struct puffs_cc));
 	if (!pcc)
@@ -150,12 +153,14 @@ puffs_cc_create(struct puffs_usermount *pu)
 
 	/* allocate stack for execution */
 	st = &pcc->pcc_uc.uc_stack;
-	st->ss_sp = pcc->pcc_stack = malloc(pu->pu_cc_stacksize);
-	if (st->ss_sp == NULL) {
+	sp = mmap(NULL, stacksize, PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE|MAP_ALIGNED(pu->pu_cc_stackshift), -1, 0);
+	if (sp == MAP_FAILED) {
 		free(pcc);
 		return NULL;
 	}
-	st->ss_size = pu->pu_cc_stacksize;
+	st->ss_sp = pcc->pcc_stack = sp;
+	st->ss_size = stacksize;
 	st->ss_flags = 0;
 
 	/*
@@ -186,7 +191,9 @@ puffs_cc_setcaller(struct puffs_cc *pcc, pid_t pid, lwpid_t lid)
 void
 puffs_cc_destroy(struct puffs_cc *pcc)
 {
+	struct puffs_usermount *pu = pcc->pcc_pu;
+	size_t stacksize = 1<<pu->pu_cc_stackshift;
 
-	free(pcc->pcc_stack);
+	munmap(pcc->pcc_stack, stacksize);
 	free(pcc);
 }
diff --git a/lib/libpuffs/puffs.c b/lib/libpuffs/puffs.c
index 07b03de97e7d..ec0cfa20f8cd 100644
--- a/lib/libpuffs/puffs.c
+++ b/lib/libpuffs/puffs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: puffs.c,v 1.68 2007/10/25 10:59:45 pooka Exp $	*/
+/*	$NetBSD: puffs.c,v 1.69 2007/10/26 13:51:14 pooka Exp $	*/
 
 /*
  * Copyright (c) 2005, 2006, 2007  Antti Kantee.  All Rights Reserved.
@@ -31,7 +31,7 @@
 
 #include <sys/cdefs.h>
 #if !defined(lint)
-__RCSID("$NetBSD: puffs.c,v 1.68 2007/10/25 10:59:45 pooka Exp $");
+__RCSID("$NetBSD: puffs.c,v 1.69 2007/10/26 13:51:14 pooka Exp $");
 #endif /* !lint */
 
 #include <sys/param.h>
@@ -147,8 +147,16 @@ puffs_getstate(struct puffs_usermount *pu)
 void
 puffs_setstacksize(struct puffs_usermount *pu, size_t ss)
 {
-
-	pu->pu_cc_stacksize = ss;
+	int stackshift;
+ 
+	assert(puffs_getstate(pu) == PUFFS_STATE_BEFOREMOUNT);
+	stackshift = -1;
+	while (ss) {
+		ss >>= 1;
+		stackshift++;
+	}
+	pu->pu_cc_stackshift = stackshift;
+	assert(1<<stackshift == ss);
 }
 
 struct puffs_pathobj *
@@ -412,7 +420,7 @@ _puffs_init(int develv, struct puffs_ops *pops, const char *mntfromname,
 	free(pops); /* XXX */
 
 	pu->pu_privdata = priv;
-	pu->pu_cc_stacksize = PUFFS_CC_STACKSIZE_DEFAULT;
+	pu->pu_cc_stackshift = PUFFS_CC_STACKSHIFT_DEFAULT;
 	LIST_INIT(&pu->pu_pnodelst);
 	LIST_INIT(&pu->pu_framectrl.fb_ios);
 	LIST_INIT(&pu->pu_ccnukelst);
diff --git a/lib/libpuffs/puffs.h b/lib/libpuffs/puffs.h
index eeec03743d50..a182310a101f 100644
--- a/lib/libpuffs/puffs.h
+++ b/lib/libpuffs/puffs.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: puffs.h,v 1.89 2007/10/21 19:25:58 pooka Exp $	*/
+/*	$NetBSD: puffs.h,v 1.90 2007/10/26 13:51:14 pooka Exp $	*/
 
 /*
  * Copyright (c) 2005, 2006, 2007  Antti Kantee.  All Rights Reserved.
@@ -116,7 +116,7 @@ struct puffs_usermount;
 /*
  * Magic constants
  */
-#define PUFFS_CC_STACKSIZE_DEFAULT (1024*1024)
+#define PUFFS_CC_STACKSHIFT_DEFAULT 18
 
 struct puffs_cn {
 	struct puffs_kcn	*pcn_pkcnp;	/* kernel input */
diff --git a/lib/libpuffs/puffs_priv.h b/lib/libpuffs/puffs_priv.h
index 0cd2c0e4dcab..2ea6964359ed 100644
--- a/lib/libpuffs/puffs_priv.h
+++ b/lib/libpuffs/puffs_priv.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: puffs_priv.h,v 1.26 2007/10/25 10:59:45 pooka Exp $	*/
+/*	$NetBSD: puffs_priv.h,v 1.27 2007/10/26 13:51:15 pooka Exp $	*/
 
 /*
  * Copyright (c) 2006 Antti Kantee.  All Rights Reserved.
@@ -97,7 +97,7 @@ struct puffs_usermount {
 	size_t			pu_maxreqlen;
 
 	uint32_t		pu_flags;
-	size_t			pu_cc_stacksize;
+	int			pu_cc_stackshift;
 
 	int			pu_kq;
 	int			pu_state;