Here's another refactoring to properly reference count a 'struct file *'
just after calling fd_getfile().
Instead of incrementing `f_count' by hand, give the current reference
to finishdup() like it is done in other places in the same file.
Ok?
Index: kern/kern_descrip.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_descrip.c,v
retrieving revision 1.144
diff -u -p -r1.144 kern_descrip.c
--- kern/kern_descrip.c 3 Apr 2018 09:00:03 -0000 1.144
+++ kern/kern_descrip.c 3 Apr 2018 13:30:47 -0000
@@ -1274,6 +1274,8 @@ dupfdopen(struct proc *p, int indx, int
struct filedesc *fdp = p->p_fd;
int dupfd = p->p_dupfd;
struct file *wfp;
+ int error, flags;
+ register_t dummy;
fdpassertlocked(fdp);
@@ -1297,24 +1299,26 @@ dupfdopen(struct proc *p, int indx, int
*/
if ((wfp = fd_getfile(fdp, dupfd)) == NULL)
return (EBADF);
+ FREF(wfp);
/*
* Check that the mode the file is being opened for is a
* subset of the mode of the existing descriptor.
*/
- if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag)
+ if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
+ FRELE(wfp, p);
return (EACCES);
- if (wfp->f_count == LONG_MAX-2)
- return (EDEADLK);
+ }
- fdp->fd_ofiles[indx] = wfp;
- fdp->fd_ofileflags[indx] = (fdp->fd_ofileflags[indx] & UF_EXCLOSE) |
- (fdp->fd_ofileflags[dupfd] & ~UF_EXCLOSE);
+ flags = fdp->fd_ofileflags[indx] & UF_EXCLOSE;
if (ISSET(p->p_p->ps_flags, PS_PLEDGE))
- fdp->fd_ofileflags[indx] |= UF_PLEDGED;
- wfp->f_count++;
- fd_used(fdp, indx);
- return (0);
+ flags |= UF_PLEDGED;
+
+ /* finishdup() does FRELE */
+ error = finishdup(p, wfp, dupfd, indx, &dummy, 1);
+ if (error == 0)
+ fdp->fd_ofileflags[indx] |= flags;
+ return (error);
}
/*
