On Tue, Apr 10, 2018 at 01:00:44PM +0200, Martin Pieuchot wrote:
> Instead of incrementing `f_count' directly, we'll use the reference that
> will be returned by fd_getfile(9). For that call FREF(9) earlier.
>
> ok?
OK bluhm@
> Index: kern/kern_descrip.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/kern_descrip.c,v
> retrieving revision 1.147
> diff -u -p -r1.147 kern_descrip.c
> --- kern/kern_descrip.c 9 Apr 2018 13:59:03 -0000 1.147
> +++ kern/kern_descrip.c 10 Apr 2018 10:53:33 -0000
> @@ -1297,22 +1297,26 @@ 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)
> + }
> + if (wfp->f_count == LONG_MAX-2) {
> + FRELE(wfp, p);
> return (EDEADLK);
> + }
>
> fdp->fd_ofiles[indx] = wfp;
> fdp->fd_ofileflags[indx] = (fdp->fd_ofileflags[indx] & UF_EXCLOSE) |
> (fdp->fd_ofileflags[dupfd] & ~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);
> }
