Re: kern/57259: ucom serial ports cannot be re-opened "too quickly" with O_NONBLOCK

["J. Hannken-Illjes" <hannken%mailbox.org@localhost>]

The following reply was made to PR kern/57259; it has been noted by GNATS.

From: "J. Hannken-Illjes" <hannken%mailbox.org@localhost>
To: NetBSD GNATS <gnats-bugs%netbsd.org@localhost>
Cc: 
Subject: Re: kern/57259: ucom serial ports cannot be re-opened "too quickly"
 with O_NONBLOCK
Date: Sun, 5 Mar 2023 14:08:29 +0100

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 > On 5. Mar 2023, at 14:00, Taylor R Campbell <riastradh%NetBSD.org@localhost> wrote:
 > 
 > I tried chasing down where this ERESTART->EINTR map came from,
 > and...it's been buried by the AT&T lawsuit.  It first appeared in
 > vfs_syscalls.c 1.31, but all revisions up through 1.30 were expunged
 > from history.
 
 According to the CSRG repo this is:
 
 --- vfs_syscalls.c      (revision 40883)
 +++ vfs_syscalls.c      (revision 40884)
 @@ -14,7 +14,7 @@
   * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
   *
 - *     @(#)vfs_syscalls.c      7.42 (Berkeley) 03/26/90
 + *     @(#)vfs_syscalls.c      7.43 (Berkeley) 04/10/90
   */
 
  #include "param.h"
 @@ -530,8 +530,10 @@
         if (error = vn_open(ndp, fmode, (cmode & 07777) &~ S_ISVTX)) {
                 crfree(fp->f_cred);
                 fp->f_count--;
 -               if (error == -1)        /* XXX from fdopen */
 -                       return (0);     /* XXX from fdopen */
 +               if (error == EJUSTRETURN)       /* XXX from fdopen */
 +                       return (0);             /* XXX from fdopen */
 +               if (error == ERESTART)
 +                       error = EINTR;
                 scp->sc_ofile[indx] = NULL;
                 return (error);
         }
 
 with log message
 
 r40884 | mckusick | 1990-04-10 22:36:33 +0200 (Tue, 10 Apr 1990) | 3 lines
 
 eliminate longjmp from the kernel (for karels)
 
 --
 J. Hannken-Illjes - hannken%mailbox.org@localhost
 
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