Add a __getcwd() syscall. This is intentionally undocumented, but all

it does is to try to figure the pwd out from the vfs namecache, and
return a reversed string to it.  libc:getcwd() is responsible for
flipping it back.

8 files changed, 112 insertions, 4 deletions

diff --git a/sys/kern/init_sysent.c b/sys/kern/init_sysent.c
index ff220b8..a86db21 100644
--- a/sys/kern/init_sysent.c
+++ b/sys/kern/init_sysent.c
@@ -358,4 +358,5 @@ struct sysent sysent[] = {
 	{ 1, (sy_call_t *)thr_wakeup },			/* 323 = thr_wakeup */
 	{ 1, (sy_call_t *)mlockall },			/* 324 = mlockall */
 	{ 0, (sy_call_t *)munlockall },			/* 325 = munlockall */
+	{ 2, (sy_call_t *)__getcwd },			/* 326 = __getcwd */
 };
diff --git a/sys/kern/syscalls.c b/sys/kern/syscalls.c
index d6946a8..21c6e76 100644
--- a/sys/kern/syscalls.c
+++ b/sys/kern/syscalls.c
@@ -347,4 +347,5 @@ char *syscallnames[] = {
 	"thr_wakeup",			/* 323 = thr_wakeup */
 	"mlockall",			/* 324 = mlockall */
 	"munlockall",			/* 325 = munlockall */
+	"__getcwd",			/* 326 = __getcwd */
 };
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index 6a19917..62673fa 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-	$Id: syscalls.master,v 1.41 1997/08/19 05:53:48 peter Exp $
+	$Id: syscalls.master,v 1.42 1997/09/14 02:22:05 peter Exp $
 ;	from: @(#)syscalls.master	8.2 (Berkeley) 1/13/94
 ;
 ; System call name/number master file.
@@ -476,3 +476,4 @@
 323     STD     BSD     { int thr_wakeup(pid_t pid); }
 324     STD     BSD     { int mlockall(int how); }
 325     STD     BSD     { int munlockall(void); }
+326     STD     BSD     { int __getcwd(u_char *buf, u_int buflen); }
diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c
index e28f93b..93e0a46 100644
--- a/sys/kern/vfs_extattr.c
+++ b/sys/kern/vfs_extattr.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_syscalls.c	8.13 (Berkeley) 4/15/94
- * $Id: vfs_syscalls.c,v 1.66 1997/07/17 07:17:33 dfr Exp $
+ * $Id: vfs_syscalls.c,v 1.67 1997/09/02 20:06:03 bde Exp $
  */
 
 /*
@@ -2763,3 +2763,52 @@ getvnode(fdp, fd, fpp)
 	*fpp = fp;
 	return (0);
 }
+#ifndef _SYS_SYSPROTO_H_
+struct  __getcwd_args {
+        u_char * buf;
+        u_int buflen;
+};
+#endif
+/* ARGSUSED */
+int
+__getcwd(p, uap, retval)
+	struct proc *p;
+	register struct __getcwd_args *uap;
+	register_t *retval;
+{
+	struct filedesc *fdp = p->p_fd;
+	struct vnode *vp;
+	struct namecache *ncp;
+	int i,j=0;
+
+	for (vp = fdp->fd_cdir; vp != fdp->fd_rdir && vp != rootvnode;) {
+		if (vp->v_dd->v_id != vp->v_ddid)
+			return(ENOENT);
+		ncp = TAILQ_FIRST(&vp->v_cache_dst);
+		if (!ncp)
+			return(ENOENT);
+		if (ncp->nc_dvp != vp->v_dd)
+			return(ENOENT);
+		for (i=ncp->nc_nlen-1; i >= 0; i--) {
+			if (uap->buflen-- < 2)
+				return(ENOMEM);
+			subyte(uap->buf, ncp->nc_name[i]);
+			uap->buf++;
+		}
+		if (uap->buflen-- < 2)
+			return(ENOMEM);
+		subyte(uap->buf, '/' );
+		uap->buf++;
+		j++;
+		vp = vp->v_dd;
+	}
+	if (!j) {
+		if (uap->buflen-- < 2)
+			return(ENOMEM);
+		subyte(uap->buf, '/' );
+		uap->buf++;
+	}
+	subyte(uap->buf, '\0' );
+	uap->buf++;
+	return (0);
+}
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index e28f93b..93e0a46 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_syscalls.c	8.13 (Berkeley) 4/15/94
- * $Id: vfs_syscalls.c,v 1.66 1997/07/17 07:17:33 dfr Exp $
+ * $Id: vfs_syscalls.c,v 1.67 1997/09/02 20:06:03 bde Exp $
  */
 
 /*
@@ -2763,3 +2763,52 @@ getvnode(fdp, fd, fpp)
 	*fpp = fp;
 	return (0);
 }
+#ifndef _SYS_SYSPROTO_H_
+struct  __getcwd_args {
+        u_char * buf;
+        u_int buflen;
+};
+#endif
+/* ARGSUSED */
+int
+__getcwd(p, uap, retval)
+	struct proc *p;
+	register struct __getcwd_args *uap;
+	register_t *retval;
+{
+	struct filedesc *fdp = p->p_fd;
+	struct vnode *vp;
+	struct namecache *ncp;
+	int i,j=0;
+
+	for (vp = fdp->fd_cdir; vp != fdp->fd_rdir && vp != rootvnode;) {
+		if (vp->v_dd->v_id != vp->v_ddid)
+			return(ENOENT);
+		ncp = TAILQ_FIRST(&vp->v_cache_dst);
+		if (!ncp)
+			return(ENOENT);
+		if (ncp->nc_dvp != vp->v_dd)
+			return(ENOENT);
+		for (i=ncp->nc_nlen-1; i >= 0; i--) {
+			if (uap->buflen-- < 2)
+				return(ENOMEM);
+			subyte(uap->buf, ncp->nc_name[i]);
+			uap->buf++;
+		}
+		if (uap->buflen-- < 2)
+			return(ENOMEM);
+		subyte(uap->buf, '/' );
+		uap->buf++;
+		j++;
+		vp = vp->v_dd;
+	}
+	if (!j) {
+		if (uap->buflen-- < 2)
+			return(ENOMEM);
+		subyte(uap->buf, '/' );
+		uap->buf++;
+	}
+	subyte(uap->buf, '\0' );
+	uap->buf++;
+	return (0);
+}
diff --git a/sys/sys/syscall-hide.h b/sys/sys/syscall-hide.h
index e023d2c..009b26d 100644
--- a/sys/sys/syscall-hide.h
+++ b/sys/sys/syscall-hide.h
@@ -245,3 +245,4 @@ HIDE_BSD(thr_sleep)
 HIDE_BSD(thr_wakeup)
 HIDE_BSD(mlockall)
 HIDE_BSD(munlockall)
+HIDE_BSD(__getcwd)
diff --git a/sys/sys/syscall.h b/sys/sys/syscall.h
index fdf4f8d..f8646a9 100644
--- a/sys/sys/syscall.h
+++ b/sys/sys/syscall.h
@@ -239,4 +239,5 @@
 #define	SYS_thr_wakeup	323
 #define	SYS_mlockall	324
 #define	SYS_munlockall	325
-#define	SYS_MAXSYSCALL	326
+#define	SYS___getcwd	326
+#define	SYS_MAXSYSCALL	327
diff --git a/sys/sys/sysproto.h b/sys/sys/sysproto.h
index 1111fbf..0a21332 100644
--- a/sys/sys/sysproto.h
+++ b/sys/sys/sysproto.h
@@ -844,6 +844,10 @@ struct	mlockall_args {
 struct	munlockall_args {
 	int dummy;
 };
+struct	__getcwd_args {
+	u_char * buf;
+	u_int buflen;
+};
 int	nosys __P((struct proc *, struct nosys_args *, int []));
 void	exit __P((struct proc *, struct rexit_args *, int [])) __dead2;
 int	fork __P((struct proc *, struct fork_args *, int []));
@@ -1047,6 +1051,7 @@ int	thr_sleep __P((struct proc *, struct thr_sleep_args *, int []));
 int	thr_wakeup __P((struct proc *, struct thr_wakeup_args *, int []));
 int	mlockall __P((struct proc *, struct mlockall_args *, int []));
 int	munlockall __P((struct proc *, struct munlockall_args *, int []));
+int	__getcwd __P((struct proc *, struct __getcwd_args *, int []));
 
 #ifdef COMPAT_43