Rewrite the code that uses the try/catch paradigm implemented by

goto and abstracted by the itry, ithrow and icatch macros (among
others). The problem with this code is that it doesn't compile on
ia64. The compiler is sufficiently confused that it inserts a call
to __ia64_save_stack_nonlock(). This is a magic function that saves
enough of the stack to allow for non-local gotos, such as would be
the case for nested functions. Since it's not a compiler defined
function, it needs a runtime implementation. This we have not in a
standalone compilation as is the kernel.

There's no indication that the compiler is not confused on other
platforms. It's likely that saving the stack in those cases is
trivial enough that the compiler doesn't need to off-load the
complexity to a runtime function.

The code is believed to be correctly translated, but has not been
tested. The overall structure remained the same, except that it's
made explicit. The macros that implement the try/catch construct
have been removed to avoid reintroduction of their use. It's not
a good idea.

In general the rewritten code is slightly more optimal in that it
doesn't need as much stack space and generally is smaller in size.

Found by: LINT

3 files changed, 116 insertions, 127 deletions

diff --git a/sys/netsmb/smb_conn.c b/sys/netsmb/smb_conn.c
index 9542160..23eb4be 100644
--- a/sys/netsmb/smb_conn.c
+++ b/sys/netsmb/smb_conn.c
@@ -128,46 +128,47 @@ smb_sm_lookupint(struct smb_vcspec *vcspec, struct smb_sharespec *shspec,
 		error = smb_vc_lock(vcp, LK_EXCLUSIVE, td);
 		if (error)
 			continue;
-		itry {
-			if ((vcp->obj.co_flags & SMBV_PRIVATE) ||
-			    !CONNADDREQ(vcp->vc_paddr, vcspec->sap) ||
-			    strcmp(vcp->vc_username, vcspec->username) != 0)
-				ithrow(1);
-			if (vcspec->owner != SMBM_ANY_OWNER) {
-				if (vcp->vc_uid != vcspec->owner)
-					ithrow(1);
-			} else
-				exact = 0;
-			if (vcspec->group != SMBM_ANY_GROUP) {
-				if (vcp->vc_grp != vcspec->group)
-					ithrow(1);
-			} else
-				exact = 0;
-
-			if (vcspec->mode & SMBM_EXACT) {
-				if (!exact ||
-				    (vcspec->mode & SMBM_MASK) != vcp->vc_mode)
-					ithrow(1);
-			}
-			if (smb_vc_access(vcp, scred, vcspec->mode) != 0)
-				ithrow(1);
-			vcspec->ssp = NULL;
-			if (shspec)
-				ithrow(smb_vc_lookupshare(vcp, shspec, scred, &vcspec->ssp));
-			error = 0;
-			break;
-		} icatch(error) {
-			smb_vc_unlock(vcp, 0, td);
-		} ifinally {
-		} iendtry;
-		if (error == 0)
-			break;
+
+		if ((vcp->obj.co_flags & SMBV_PRIVATE) ||
+		    !CONNADDREQ(vcp->vc_paddr, vcspec->sap) ||
+		    strcmp(vcp->vc_username, vcspec->username) != 0)
+			goto err1;
+		if (vcspec->owner != SMBM_ANY_OWNER) {
+			if (vcp->vc_uid != vcspec->owner)
+				goto err1;
+		} else
+			exact = 0;
+		if (vcspec->group != SMBM_ANY_GROUP) {
+			if (vcp->vc_grp != vcspec->group)
+				goto err1;
+		} else
+			exact = 0;
+		if (vcspec->mode & SMBM_EXACT) {
+			if (!exact || (vcspec->mode & SMBM_MASK) !=
+			    vcp->vc_mode)
+				goto err1;
+		}
+		if (smb_vc_access(vcp, scred, vcspec->mode) != 0)
+			goto err1;
+		vcspec->ssp = NULL;
+		if (shspec) {
+			error = (int)smb_vc_lookupshare(vcp, shspec, scred,
+			    &vcspec->ssp);
+			if (error)
+				goto fail;
+		}
+		error = 0;
+		break;
+	err1:
+		error = 1;
+	fail:
+		smb_vc_unlock(vcp, 0, td);
 	}
 	if (vcp) {
 		smb_vc_ref(vcp);
 		*vcpp = vcp;
 	}
-	return error;
+	return (error);
 }
 
 int
@@ -413,39 +414,53 @@ smb_vc_create(struct smb_vcspec *vcspec,
 	vcp->vc_grp = gid;
 
 	smb_sl_init(&vcp->vc_stlock, "vcstlock");
-	error = 0;
-	itry {
-		vcp->vc_paddr = dup_sockaddr(vcspec->sap, 1);
-		ierror(vcp->vc_paddr == NULL, ENOMEM);
-
-		vcp->vc_laddr = dup_sockaddr(vcspec->lap, 1);
-		ierror(vcp->vc_laddr == NULL, ENOMEM);
-
-		ierror((vcp->vc_pass = smb_strdup(vcspec->pass)) == NULL, ENOMEM);
-
-		vcp->vc_domain = smb_strdup((domain && domain[0]) ? domain : "NODOMAIN");
-		ierror(vcp->vc_domain == NULL, ENOMEM);
-
-		ierror((vcp->vc_srvname = smb_strdup(vcspec->srvname)) == NULL, ENOMEM);
-		ierror((vcp->vc_username = smb_strdup(vcspec->username)) == NULL, ENOMEM);
-
-		ithrow(iconv_open("tolower", vcspec->localcs, &vcp->vc_tolower));
-		ithrow(iconv_open("toupper", vcspec->localcs, &vcp->vc_toupper));
-		if (vcspec->servercs[0]) {
-			ithrow(iconv_open(vcspec->servercs, vcspec->localcs,
-			    &vcp->vc_toserver));
-			ithrow(iconv_open(vcspec->localcs, vcspec->servercs,
-			    &vcp->vc_tolocal));
-		}
-
-		ithrow(smb_iod_create(vcp));
-		*vcpp = vcp;
-		smb_co_addchild(&smb_vclist, VCTOCP(vcp));
-	} icatch(error) {
-		smb_vc_put(vcp, scred);
-	} ifinally {
-	} iendtry;
-	return error;
+	error = ENOMEM;
+
+	vcp->vc_paddr = dup_sockaddr(vcspec->sap, 1);
+	if (vcp->vc_paddr == NULL)
+		goto fail;
+	vcp->vc_laddr = dup_sockaddr(vcspec->lap, 1);
+	if (vcp->vc_laddr == NULL)
+		goto fail;
+	vcp->vc_pass = smb_strdup(vcspec->pass);
+	if (vcp->vc_pass == NULL)
+		goto fail;
+	vcp->vc_domain = smb_strdup((domain && domain[0]) ? domain :
+	    "NODOMAIN");
+	if (vcp->vc_domain == NULL)
+		goto fail;
+	vcp->vc_srvname = smb_strdup(vcspec->srvname);
+	if (vcp->vc_srvname == NULL)
+		goto fail;
+	vcp->vc_username = smb_strdup(vcspec->username);
+	if (vcp->vc_username == NULL)
+		goto fail;
+	error = (int)iconv_open("tolower", vcspec->localcs, &vcp->vc_tolower);
+	if (error)
+		goto fail;
+	error = (int)iconv_open("toupper", vcspec->localcs, &vcp->vc_toupper);
+	if (error)
+		goto fail;
+	if (vcspec->servercs[0]) {
+		error = (int)iconv_open(vcspec->servercs, vcspec->localcs,
+		    &vcp->vc_toserver);
+		if (error)
+			goto fail;
+		error = (int)iconv_open(vcspec->localcs, vcspec->servercs,
+		    &vcp->vc_tolocal);
+		if (error)
+			goto fail;
+	}
+	error = (int)smb_iod_create(vcp);
+	if (error)
+		goto fail;
+	*vcpp = vcp;
+	smb_co_addchild(&smb_vclist, VCTOCP(vcp));
+	return (0);
+
+ fail:
+	smb_vc_put(vcp, scred);
+	return (error);
 }
 
 static void
diff --git a/sys/netsmb/smb_iod.c b/sys/netsmb/smb_iod.c
index 2c5e2c3..ae9c457 100644
--- a/sys/netsmb/smb_iod.c
+++ b/sys/netsmb/smb_iod.c
@@ -141,29 +141,39 @@ smb_iod_connect(struct smbiod *iod)
 	}
 	vcp->vc_genid++;
 	error = 0;
-	itry {
-		ithrow(SMB_TRAN_CREATE(vcp, td));
-		SMBIODEBUG("tcreate\n");
-		if (vcp->vc_laddr) {
-			ithrow(SMB_TRAN_BIND(vcp, vcp->vc_laddr, td));
-		}
-		SMBIODEBUG("tbind\n");
-		ithrow(SMB_TRAN_CONNECT(vcp, vcp->vc_paddr, td));
-		SMB_TRAN_SETPARAM(vcp, SMBTP_SELECTID, &iod->iod_flags);
-		iod->iod_state = SMBIOD_ST_TRANACTIVE;
-		SMBIODEBUG("tconnect\n");
-/*		vcp->vc_mid = 0;*/
-		ithrow(smb_smb_negotiate(vcp, &iod->iod_scred));
-		SMBIODEBUG("snegotiate\n");
-		ithrow(smb_smb_ssnsetup(vcp, &iod->iod_scred));
-		iod->iod_state = SMBIOD_ST_VCACTIVE;
-		SMBIODEBUG("completed\n");
-		smb_iod_invrq(iod);
-	} icatch(error) {
-		smb_iod_dead(iod);
-	} ifinally {
-	} iendtry;
-	return error;
+
+	error = (int)SMB_TRAN_CREATE(vcp, td);
+	if (error)
+		goto fail;
+	SMBIODEBUG("tcreate\n");
+	if (vcp->vc_laddr) {
+		error = (int)SMB_TRAN_BIND(vcp, vcp->vc_laddr, td);
+		if (error)
+			goto fail;
+	}
+	SMBIODEBUG("tbind\n");
+	error = (int)SMB_TRAN_CONNECT(vcp, vcp->vc_paddr, td);
+	if (error)
+		goto fail;
+	SMB_TRAN_SETPARAM(vcp, SMBTP_SELECTID, &iod->iod_flags);
+	iod->iod_state = SMBIOD_ST_TRANACTIVE;
+	SMBIODEBUG("tconnect\n");
+	/* vcp->vc_mid = 0;*/
+	error = (int)smb_smb_negotiate(vcp, &iod->iod_scred);
+	if (error)
+		goto fail;
+	SMBIODEBUG("snegotiate\n");
+	error = (int)smb_smb_ssnsetup(vcp, &iod->iod_scred);
+	if (error)
+		goto fail;
+	iod->iod_state = SMBIOD_ST_VCACTIVE;
+	SMBIODEBUG("completed\n");
+	smb_iod_invrq(iod);
+	return (0);
+
+ fail:
+	smb_iod_dead(iod);
+	return (error);
 }
 
 static int
diff --git a/sys/netsmb/smb_subr.h b/sys/netsmb/smb_subr.h
index 684f6bb..276190f 100644
--- a/sys/netsmb/smb_subr.h
+++ b/sys/netsmb/smb_subr.h
@@ -86,42 +86,6 @@ void m_dumpm(struct mbuf *m);
 
 #define SMB_STRFREE(p)	do { if (p) smb_strfree(p); } while(0)
 
-/*
- * The simple try/catch/finally interface.
- * With GCC it is possible to allow more than one try/finally block per
- * function, but we'll avoid it to maintain portability.
- */
-#define itry		{						\
-				__label__ _finlab, _catchlab;		\
-				int _tval;				\
-
-#define icatch(var)							\
-				goto _finlab;				\
-				(void)&&_catchlab;			\
-				_catchlab:				\
-				var = _tval;
-
-#define ifinally		(void)&&_finlab;			\
-				_finlab:				
-#define iendtry		}
-
-#define inocatch							\
-				goto _finlab;				\
-				(void)&&_catchlab;			\
-				_catchlab:				\
-
-#define ithrow(t)	do {						\
-				if ((_tval = (int)(t)) != 0)		\
-					goto _catchlab;			\
-			} while (0)
-
-#define ierror(t,e)	do {						\
-				if (t) {				\
-					_tval = e;			\
-					goto _catchlab;			\
-				}					\
-			} while (0)
-
 typedef u_int16_t	smb_unichar;
 typedef	smb_unichar	*smb_uniptr;