Fix the ABI wrappers to use kern_fcntl() rather than calling fcntl()

directly.  This removes a few more users of the stackgap and also marks
the syscalls using these wrappers MP safe where appropriate.

Tested on:	i386 with linux acroread5
Compiled on:	i386, alpha LINT

4 files changed, 56 insertions, 88 deletions

diff --git a/sys/compat/linux/linux_socket.c b/sys/compat/linux/linux_socket.c
index 47cf5d6..8233db1 100644
--- a/sys/compat/linux/linux_socket.c
+++ b/sys/compat/linux/linux_socket.c
@@ -674,12 +674,7 @@ linux_accept(struct thread *td, struct linux_accept_args *args)
 	struct close_args /* {
 		int     fd;
 	} */ c_args;
-	struct fcntl_args /* {
-		int	fd;
-		int	cmd;
-		long	arg;
-	} */ f_args;
-	int error;
+	int error, fd;
 
 	if ((error = copyin(args, &linux_args, sizeof(linux_args))))
 		return (error);
@@ -705,11 +700,9 @@ linux_accept(struct thread *td, struct linux_accept_args *args)
 	 * accepted one, so we must clear the flags in the new descriptor.
 	 * Ignore any errors, because we already have an open fd.
 	 */
-	f_args.fd = td->td_retval[0];
-	f_args.cmd = F_SETFL;
-	f_args.arg = 0;
-	(void)fcntl(td, &f_args);
-	td->td_retval[0] = f_args.fd;
+	fd = td->td_retval[0];
+	(void)kern_fcntl(td, fd, F_SETFL, 0);
+	td->td_retval[0] = fd;
 	return (0);
 }
 
diff --git a/sys/compat/svr4/svr4_fcntl.c b/sys/compat/svr4/svr4_fcntl.c
index 7a01b15..0c592c3 100644
--- a/sys/compat/svr4/svr4_fcntl.c
+++ b/sys/compat/svr4/svr4_fcntl.c
@@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/namei.h>
 #include <sys/proc.h>
 #include <sys/stat.h>
+#include <sys/syscallsubr.h>
 #include <sys/unistd.h>
 #include <sys/vnode.h>
 
@@ -580,29 +581,24 @@ svr4_sys_fcntl(td, uap)
 	register struct thread *td;
 	struct svr4_sys_fcntl_args *uap;
 {
-	int				error;
-	struct fcntl_args		fa;
-	int                             *retval;
+	int cmd, error, *retval;
 
 	retval = td->td_retval;
 
-	fa.fd = uap->fd;
-	fa.cmd = svr4_to_bsd_cmd(uap->cmd);
+	cmd = svr4_to_bsd_cmd(uap->cmd);
 
-	switch (fa.cmd) {
+	switch (cmd) {
 	case F_DUPFD:
 	case F_GETFD:
 	case F_SETFD:
-		fa.arg = (long) uap->arg;
-		return fcntl(td, &fa);
+		return (kern_fcntl(td, uap->fd, cmd, (intptr_t)uap->arg));
 
 	case F_GETFL:
-		fa.arg = (long) uap->arg;
-		error = fcntl(td, &fa);
+		error = kern_fcntl(td, uap->fd, cmd, (intptr_t)uap->arg);
 		if (error)
-			return error;
+			return (error);
 		*retval = bsd_to_svr4_flags(*retval);
-		return error;
+		return (error);
 
 	case F_SETFL:
 		{
@@ -610,55 +606,39 @@ svr4_sys_fcntl(td, uap)
 			 * we must save the O_ASYNC flag, as that is
 			 * handled by ioctl(_, I_SETSIG, _) emulation.
 			 */
-			long cmd;
 			int flags;
 
 			DPRINTF(("Setting flags %p\n", uap->arg));
-			cmd = fa.cmd; /* save it for a while */
 
-			fa.cmd = F_GETFL;
-			if ((error = fcntl(td, &fa)) != 0)
-				return error;
+			error = kern_fcntl(td, uap->fd, F_GETFL, 0);
+			if (error)
+				return (error);
 			flags = *retval;
 			flags &= O_ASYNC;
 			flags |= svr4_to_bsd_flags((u_long) uap->arg);
-			fa.cmd = cmd;
-			fa.arg = (long) flags;
-			return fcntl(td, &fa);
+			return (kern_fcntl(td, uap->fd, F_SETFL, flags));
 		}
 
 	case F_GETLK:
 	case F_SETLK:
 	case F_SETLKW:
 		{
-			struct svr4_flock	 ifl;
-			struct flock		*flp, fl;
-			caddr_t sg = stackgap_init();
-
-			flp = stackgap_alloc(&sg, sizeof(struct flock));
-			fa.arg = (long) flp;
+			struct svr4_flock	ifl;
+			struct flock		fl;
 
-			error = copyin(uap->arg, &ifl, sizeof ifl);
+			error = copyin(uap->arg, &ifl, sizeof (ifl));
 			if (error)
-				return error;
+				return (error);
 
 			svr4_to_bsd_flock(&ifl, &fl);
 
-			error = copyout(&fl, flp, sizeof fl);
-			if (error)
-				return error;
-
-			error = fcntl(td, &fa);
-			if (error || fa.cmd != F_GETLK)
-				return error;
-
-			error = copyin(flp, &fl, sizeof fl);
-			if (error)
-				return error;
+			error = kern_fcntl(td, uap->fd, cmd, (intptr_t)&fl);
+			if (error || cmd != F_GETLK)
+				return (error);
 
 			bsd_to_svr4_flock(&fl, &ifl);
 
-			return copyout(&ifl, uap->arg, sizeof ifl);
+			return (copyout(&ifl, uap->arg, sizeof (ifl)));
 		}
 	case -1:
 		switch (uap->cmd) {
@@ -692,36 +672,36 @@ svr4_sys_fcntl(td, uap)
 		case SVR4_F_SETLK64:
 		case SVR4_F_SETLKW64:
 			{
-				struct svr4_flock64	 ifl;
-				struct flock		*flp, fl;
-				caddr_t sg = stackgap_init();
-
-				flp = stackgap_alloc(&sg, sizeof(struct flock));
-				fa.arg = (long) flp;
-
+				struct svr4_flock64	ifl;
+				struct flock		fl;
+
+				switch (uap->cmd) {
+				case SVR4_F_GETLK64:
+					cmd = F_GETLK;
+					break;
+				case SVR4_F_SETLK64:
+					cmd = F_SETLK;
+					break;					
+				case SVR4_F_SETLKW64:
+					cmd = F_SETLKW;
+					break;
+				}
 				error = copyin(uap->arg, &ifl,
-				    sizeof ifl);
+				    sizeof (ifl));
 				if (error)
-					return error;
+					return (error);
 
 				svr4_to_bsd_flock64(&ifl, &fl);
 
-				error = copyout(&fl, flp, sizeof fl);
-				if (error)
-					return error;
-
-				error = fcntl(td, &fa);
-				if (error || fa.cmd != F_GETLK)
-					return error;
-
-				error = copyin(flp, &fl, sizeof fl);
-				if (error)
-					return error;
+				error = kern_fcntl(td, uap->fd, cmd,
+				    (intptr_t)&fl);
+				if (error || cmd != F_GETLK)
+					return (error);
 
 				bsd_to_svr4_flock64(&fl, &ifl);
 
-				return copyout(&ifl, uap->arg,
-				    sizeof ifl);
+				return (copyout(&ifl, uap->arg,
+				    sizeof (ifl)));
 			}
 
 		case SVR4_F_FREESP64:
diff --git a/sys/compat/svr4/svr4_stream.c b/sys/compat/svr4/svr4_stream.c
index d91c185..0e708f6 100644
--- a/sys/compat/svr4/svr4_stream.c
+++ b/sys/compat/svr4/svr4_stream.c
@@ -60,6 +60,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/stat.h>
+#include <sys/syscallsubr.h>
 #include <sys/sysproto.h>
 #include <sys/uio.h>
 #include <sys/ktrace.h>		/* Must come after sys/uio.h */
@@ -1473,7 +1474,6 @@ i_setsig(fp, td, retval, fd, cmd, dat)
 	 * We alse have to fix the O_ASYNC fcntl bit, so the
 	 * process will get SIGPOLLs.
 	 */
-	struct fcntl_args fa;
 	int error;
 	register_t oflags, flags;
 	struct svr4_strm *st = svr4_stream_get(fp);
@@ -1483,10 +1483,9 @@ i_setsig(fp, td, retval, fd, cmd, dat)
 		return EINVAL;
 	}
 	/* get old status flags */
-	fa.fd = fd;
-	fa.cmd = F_GETFL;
-	if ((error = fcntl(td, &fa)) != 0)
-		return error;
+	error = kern_fcntl(td, fd, F_GETFL, 0);
+	if (error)
+		return (error);
 
 	oflags = td->td_retval[0];
 
@@ -1512,19 +1511,15 @@ i_setsig(fp, td, retval, fd, cmd, dat)
 
 	/* set the new flags, if changed */
 	if (flags != oflags) {
-		fa.cmd = F_SETFL;
-		fa.arg = (long) flags;
-		if ((error = fcntl(td, &fa)) != 0)
-			  return error;
+		error = kern_fcntl(td, fd, F_SETFL, flags);
+		if (error)
+			return (error);
 		flags = td->td_retval[0];
 	}
 
 	/* set up SIGIO receiver if needed */
-	if (dat != NULL) {
-		fa.cmd = F_SETOWN;
-		fa.arg = (long) td->td_proc->p_pid;
-		return fcntl(td, &fa);
-	}
+	if (dat != NULL)
+		return (kern_fcntl(td, fd, F_SETOWN, td->td_proc->p_pid));
 	return 0;
 }
 
diff --git a/sys/compat/svr4/syscalls.master b/sys/compat/svr4/syscalls.master
index 277fbdc..6343597 100644
--- a/sys/compat/svr4/syscalls.master
+++ b/sys/compat/svr4/syscalls.master
@@ -100,7 +100,7 @@
 59	STD	{ int svr4_sys_execve(char *path, char **argp, char **envp); }
 60	MNOPROTO { int umask(int newmask); }
 61	NOPROTO	{ int chroot(char *path); }
-62	STD	{ int svr4_sys_fcntl(int fd, int cmd, char *arg); }
+62	MSTD	{ int svr4_sys_fcntl(int fd, int cmd, char *arg); }
 63	MSTD	{ int svr4_sys_ulimit(int cmd, long newlimit); }
 64	UNIMPL	reserved
 65	UNIMPL	reserved