From 4966e1c1dec763e6e263d6353fcdd7892da5481b Mon Sep 17 00:00:00 2001
From: pooka <pooka@NetBSD.org>
Date: Thu, 10 May 2007 12:26:28 +0000
Subject: [PATCH] Add some kludges to be able to execute requests on the
 regular program stack instead of the continuation stack.  This is for
 lib/36011, where pthread gets confused since we aren't running on the regular
 stack. I'm not really sure which direction to go to with this quite yet, so
 make the hack hard to enable on purpose.  The whole request dispatch code
 needs cleaning anyway.

---
 lib/libpuffs/puffs.c      | 50 +++++++++++++++++++++++++++++----------
 lib/libpuffs/puffs_priv.h |  6 ++---
 2 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/lib/libpuffs/puffs.c b/lib/libpuffs/puffs.c
index 2f2ba8b04fd0..fe8cdaab1e5b 100644
--- a/lib/libpuffs/puffs.c
+++ b/lib/libpuffs/puffs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: puffs.c,v 1.42 2007/05/09 18:36:52 pooka Exp $	*/
+/*	$NetBSD: puffs.c,v 1.43 2007/05/10 12:26:28 pooka Exp $	*/
 
 /*
  * Copyright (c) 2005, 2006  Antti Kantee.  All Rights Reserved.
@@ -34,7 +34,7 @@
 
 #include <sys/cdefs.h>
 #if !defined(lint)
-__RCSID("$NetBSD: puffs.c,v 1.42 2007/05/09 18:36:52 pooka Exp $");
+__RCSID("$NetBSD: puffs.c,v 1.43 2007/05/10 12:26:28 pooka Exp $");
 #endif /* !lint */
 
 #include <sys/param.h>
@@ -56,6 +56,13 @@ __RCSID("$NetBSD: puffs.c,v 1.42 2007/05/09 18:36:52 pooka Exp $");
 
 #include "puffs_priv.h"
 
+/*
+ * Set the following to 1 to not handle each request on a separate
+ * stack.  This is highly volatile kludge, therefore no external
+ * interface.
+ */
+int puffs_fakecc;
+
 /* Most file systems want this for opts, so just give it to them */
 const struct mntopt puffsmopts[] = {
 	MOPT_STDOPTS,
@@ -452,6 +459,7 @@ int
 puffs_dopreq(struct puffs_usermount *pu, struct puffs_req *preq,
 	struct puffs_putreq *ppr)
 {
+	struct puffs_cc fakecc;
 	struct puffs_cc *pcc;
 	int rv;
 
@@ -474,13 +482,22 @@ puffs_dopreq(struct puffs_usermount *pu, struct puffs_req *preq,
 	if (pu->pu_flags & PUFFS_FLAG_OPDUMP)
 		puffsdump_req(preq);
 
-	pcc = puffs_cc_create(pu);
+	if (puffs_fakecc) {
+		pcc = &fakecc;
+		pcc_init_local(pcc);
 
-	/* XXX: temporary kludging */
-	pcc->pcc_preq = malloc(preq->preq_buflen);
-	if (pcc->pcc_preq == NULL)
-		return -1;
-	(void) memcpy(pcc->pcc_preq, preq, preq->preq_buflen);
+		pcc->pcc_pu = pu;
+		pcc->pcc_preq = preq;
+		pcc->pcc_flags = PCC_FAKECC;
+	} else {
+		pcc = puffs_cc_create(pu);
+
+		/* XXX: temporary kludging */
+		pcc->pcc_preq = malloc(preq->preq_buflen);
+		if (pcc->pcc_preq == NULL)
+			return -1;
+		(void) memcpy(pcc->pcc_preq, preq, preq->preq_buflen);
+	}
 
 	rv = puffs_docc(pcc, ppr);
 
@@ -500,7 +517,10 @@ puffs_docc(struct puffs_cc *pcc, struct puffs_putreq *ppr)
 
 	assert((pcc->pcc_flags & PCC_DONE) == 0);
 
-	puffs_cc_continue(pcc);
+	if (pcc->pcc_flags & PCC_REALCC)
+		puffs_cc_continue(pcc);
+	else
+		puffs_calldispatcher(pcc);
 	rv = pcc->pcc_rv;
 
 	if ((pcc->pcc_flags & PCC_DONE) == 0)
@@ -512,12 +532,18 @@ puffs_docc(struct puffs_cc *pcc, struct puffs_putreq *ppr)
 		if (pu->pu_flags & PUFFS_FLAG_OPDUMP)
 			puffsdump_rv(pcc->pcc_preq);
 
-		puffs_req_putcc(ppr, pcc);
+		if (pcc->pcc_flags & PCC_REALCC)
+			puffs_req_putcc(ppr, pcc);
+		else
+			puffs_req_put(ppr, pcc->pcc_preq);
 		break;
 	case PUFFCALL_IGNORE:
-		puffs_cc_destroy(pcc);
+		if (pcc->pcc_flags & PCC_REALCC)
+			puffs_cc_destroy(pcc);
 		break;
 	case PUFFCALL_AGAIN:
+		if (pcc->pcc_flags & PCC_FAKECC)
+			assert(pcc->pcc_flags & PCC_DONE);
 		break;
 	default:
 		assert(/*CONSTCOND*/0);
@@ -538,7 +564,7 @@ puffs_calldispatcher(struct puffs_cc *pcc)
 	void *opcookie = preq->preq_cookie;
 	int error, rv, buildpath;
 
-	assert(pcc->pcc_flags & (PCC_ONCE | PCC_REALCC));
+	assert(pcc->pcc_flags & (PCC_FAKECC | PCC_REALCC));
 
 	if (PUFFSOP_WANTREPLY(preq->preq_opclass))
 		rv = PUFFCALL_ANSWER;
diff --git a/lib/libpuffs/puffs_priv.h b/lib/libpuffs/puffs_priv.h
index 2992f96e6470..4fcbc616474b 100644
--- a/lib/libpuffs/puffs_priv.h
+++ b/lib/libpuffs/puffs_priv.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: puffs_priv.h,v 1.7 2007/05/05 15:48:18 pooka Exp $	*/
+/*	$NetBSD: puffs_priv.h,v 1.8 2007/05/10 12:26:28 pooka Exp $	*/
 
 /*
  * Copyright (c) 2006 Antti Kantee.  All Rights Reserved.
@@ -88,7 +88,7 @@ struct puffs_cc {
 
 	TAILQ_ENTRY(puffs_cc)	entries;
 };
-#define PCC_ONCE	0x01
+#define PCC_FAKECC	0x01
 #define PCC_REALCC	0x02
 #define PCC_FREEPRIV	0x04
 #define PCC_PREQ_NOCOPY	0x08
@@ -105,7 +105,7 @@ struct puffs_cc {
 #define pcc_init_local(ap)   						\
 do {									\
 	memset(ap, 0, sizeof(*ap));					\
-	(ap)->pcc_flags = PCC_ONCE;					\
+	(ap)->pcc_flags = PCC_FAKECC;					\
 } while (/*CONSTCOND*/0)
 
 /*