svn commit: r285356 - in head/sys: compat/cloudabi kern sys

Mateusz Guzik mjg at FreeBSD.org
Fri Jul 10 11:01:33 UTC 2015


Author: mjg
Date: Fri Jul 10 11:01:30 2015
New Revision: 285356
URL: https://svnweb.freebsd.org/changeset/base/285356

Log:
  fd: split kern_dup flags argument into actual flags and a mode
  
  Tidy up the code inside to switch on the mode.

Modified:
  head/sys/compat/cloudabi/cloudabi_fd.c
  head/sys/kern/kern_descrip.c
  head/sys/sys/filedesc.h
  head/sys/sys/syscallsubr.h

Modified: head/sys/compat/cloudabi/cloudabi_fd.c
==============================================================================
--- head/sys/compat/cloudabi/cloudabi_fd.c	Fri Jul 10 09:20:13 2015	(r285355)
+++ head/sys/compat/cloudabi/cloudabi_fd.c	Fri Jul 10 11:01:30 2015	(r285356)
@@ -97,7 +97,7 @@ cloudabi_sys_fd_replace(struct thread *t
 	 * clear the return value, as this system call yields no return
 	 * value.
 	 */
-	error = kern_dup(td, FDDUP_MUSTREPLACE, uap->from, uap->to);
+	error = kern_dup(td, FDDUP_MUSTREPLACE, 0, uap->from, uap->to);
 	td->td_retval[0] = 0;
 	return (error);
 }

Modified: head/sys/kern/kern_descrip.c
==============================================================================
--- head/sys/kern/kern_descrip.c	Fri Jul 10 09:20:13 2015	(r285355)
+++ head/sys/kern/kern_descrip.c	Fri Jul 10 11:01:30 2015	(r285356)
@@ -355,7 +355,7 @@ int
 sys_dup2(struct thread *td, struct dup2_args *uap)
 {
 
-	return (kern_dup(td, FDDUP_FIXED, (int)uap->from, (int)uap->to));
+	return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to));
 }
 
 /*
@@ -371,7 +371,7 @@ int
 sys_dup(struct thread *td, struct dup_args *uap)
 {
 
-	return (kern_dup(td, 0, (int)uap->fd, 0));
+	return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0));
 }
 
 /*
@@ -481,22 +481,22 @@ kern_fcntl(struct thread *td, int fd, in
 	switch (cmd) {
 	case F_DUPFD:
 		tmp = arg;
-		error = kern_dup(td, FDDUP_FCNTL, fd, tmp);
+		error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp);
 		break;
 
 	case F_DUPFD_CLOEXEC:
 		tmp = arg;
-		error = kern_dup(td, FDDUP_FCNTL | FDDUP_CLOEXEC, fd, tmp);
+		error = kern_dup(td, FDDUP_FCNTL, FDDUP_CLOEXEC, fd, tmp);
 		break;
 
 	case F_DUP2FD:
 		tmp = arg;
-		error = kern_dup(td, FDDUP_FIXED, fd, tmp);
+		error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp);
 		break;
 
 	case F_DUP2FD_CLOEXEC:
 		tmp = arg;
-		error = kern_dup(td, FDDUP_FIXED | FDDUP_CLOEXEC, fd, tmp);
+		error = kern_dup(td, FDDUP_FIXED, FDDUP_CLOEXEC, fd, tmp);
 		break;
 
 	case F_GETFD:
@@ -789,7 +789,7 @@ getmaxfd(struct thread *td)
  * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
  */
 int
-kern_dup(struct thread *td, int flags, int old, int new)
+kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
 {
 	struct filedesc *fdp;
 	struct filedescent *oldfde, *newfde;
@@ -801,10 +801,8 @@ kern_dup(struct thread *td, int flags, i
 	p = td->td_proc;
 	fdp = p->p_fd;
 
-	MPASS((flags & ~(FDDUP_FIXED | FDDUP_FCNTL | FDDUP_CLOEXEC |
-	    FDDUP_MUSTREPLACE)) == 0);
-	MPASS((flags & (FDDUP_FIXED | FDDUP_MUSTREPLACE)) !=
-	    (FDDUP_FIXED | FDDUP_MUSTREPLACE));
+	MPASS((flags & ~(FDDUP_CLOEXEC)) == 0);
+	MPASS(mode < FDDUP_LASTMODE);
 
 	/*
 	 * Verify we have a valid descriptor to dup from and possibly to
@@ -825,7 +823,7 @@ kern_dup(struct thread *td, int flags, i
 		return (EBADF);
 	}
 	oldfde = &fdp->fd_ofiles[old];
-	if (flags & (FDDUP_FIXED | FDDUP_MUSTREPLACE) && old == new) {
+	if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) {
 		td->td_retval[0] = new;
 		if (flags & FDDUP_CLOEXEC)
 			fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
@@ -840,7 +838,17 @@ kern_dup(struct thread *td, int flags, i
 	 * table is large enough to hold it, and grab it.  Otherwise, just
 	 * allocate a new descriptor the usual way.
 	 */
-	if (flags & FDDUP_MUSTREPLACE) {
+	switch (mode) {
+	case FDDUP_NORMAL:
+	case FDDUP_FCNTL:
+		if ((error = fdalloc(td, new, &new)) != 0) {
+			FILEDESC_XUNLOCK(fdp);
+			fdrop(fp, td);
+			return (error);
+		}
+		newfde = &fdp->fd_ofiles[new];
+		break;
+	case FDDUP_MUSTREPLACE:
 		/* Target file descriptor must exist. */
 		if (new >= fdp->fd_nfiles ||
 		    fdp->fd_ofiles[new].fde_file == NULL) {
@@ -849,7 +857,8 @@ kern_dup(struct thread *td, int flags, i
 			return (EBADF);
 		}
 		newfde = &fdp->fd_ofiles[new];
-	} else if (flags & FDDUP_FIXED) {
+		break;
+	case FDDUP_FIXED:
 		if (new >= fdp->fd_nfiles) {
 			/*
 			 * The resource limits are here instead of e.g.
@@ -877,13 +886,12 @@ kern_dup(struct thread *td, int flags, i
 		newfde = &fdp->fd_ofiles[new];
 		if (newfde->fde_file == NULL)
 			fdused(fdp, new);
-	} else {
-		if ((error = fdalloc(td, new, &new)) != 0) {
-			FILEDESC_XUNLOCK(fdp);
-			fdrop(fp, td);
-			return (error);
-		}
-		newfde = &fdp->fd_ofiles[new];
+		break;
+#ifdef INVARIANTS
+	default:
+		newfde = NULL; /* silence the compiler */
+		KASSERT(0, ("%s unsupported mode %d", __func__, mode));
+#endif
 	}
 
 	KASSERT(fp == oldfde->fde_file, ("old fd has been modified"));
@@ -2223,7 +2231,7 @@ fdcheckstd(struct thread *td)
 
 		save = td->td_retval[0];
 		if (devnull != -1) {
-			error = kern_dup(td, FDDUP_FIXED, devnull, i);
+			error = kern_dup(td, FDDUP_FIXED, 0, devnull, i);
 		} else {
 			error = kern_openat(td, AT_FDCWD, "/dev/null",
 			    UIO_SYSSPACE, O_RDWR, 0);

Modified: head/sys/sys/filedesc.h
==============================================================================
--- head/sys/sys/filedesc.h	Fri Jul 10 09:20:13 2015	(r285355)
+++ head/sys/sys/filedesc.h	Fri Jul 10 11:01:30 2015	(r285356)
@@ -134,11 +134,17 @@ struct filedesc_to_leader {
 					    SX_NOTRECURSED)
 #define	FILEDESC_UNLOCK_ASSERT(fdp)	sx_assert(&(fdp)->fd_sx, SX_UNLOCKED)
 
+/* Operation types for kern_dup(). */
+enum {
+	FDDUP_NORMAL = 0x01,	/* dup() behavior. */
+	FDDUP_FCNTL,		/* fcntl()-style errors. */
+	FDDUP_FIXED,		/* Force fixed allocation. */
+	FDDUP_MUSTREPLACE,	/* Target must exist. */
+	FDDUP_LASTMODE,
+};
+
 /* Flags for kern_dup(). */
-#define	FDDUP_FIXED		0x1	/* Force fixed allocation. */
-#define	FDDUP_FCNTL		0x2	/* fcntl()-style errors. */
-#define	FDDUP_CLOEXEC		0x4	/* Atomically set FD_CLOEXEC. */
-#define	FDDUP_MUSTREPLACE	0x8	/* Target must exist. */
+#define	FDDUP_CLOEXEC		0x1	/* Atomically set FD_CLOEXEC. */
 
 struct thread;
 

Modified: head/sys/sys/syscallsubr.h
==============================================================================
--- head/sys/sys/syscallsubr.h	Fri Jul 10 09:20:13 2015	(r285355)
+++ head/sys/sys/syscallsubr.h	Fri Jul 10 11:01:30 2015	(r285356)
@@ -85,7 +85,7 @@ int	kern_clock_settime(struct thread *td
 int	kern_close(struct thread *td, int fd);
 int	kern_connectat(struct thread *td, int dirfd, int fd,
 	    struct sockaddr *sa);
-int	kern_dup(struct thread *td, int flags, int old, int new);
+int	kern_dup(struct thread *td, u_int mode, int flags, int old, int new);
 int	kern_execve(struct thread *td, struct image_args *args,
 	    struct mac *mac_p);
 int	kern_fchmodat(struct thread *td, int fd, char *path,


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