From owner-freebsd-hackers@FreeBSD.ORG Thu Jul 27 17:35:18 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F0FBD16A515 for ; Thu, 27 Jul 2006 17:35:17 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (66-23-211-162.clients.speedfactory.net [66.23.211.162]) by mx1.FreeBSD.org (Postfix) with ESMTP id A717643D46 for ; Thu, 27 Jul 2006 17:35:00 +0000 (GMT) (envelope-from jhb@freebsd.org) Received: from localhost.corp.yahoo.com (john@localhost [127.0.0.1]) (authenticated bits=0) by server.baldwin.cx (8.13.4/8.13.4) with ESMTP id k6RHYrn6078521; Thu, 27 Jul 2006 13:34:59 -0400 (EDT) (envelope-from jhb@freebsd.org) From: John Baldwin To: freebsd-hackers@freebsd.org Date: Thu, 27 Jul 2006 11:41:00 -0400 User-Agent: KMail/1.9.1 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200607271141.01285.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [127.0.0.1]); Thu, 27 Jul 2006 13:34:59 -0400 (EDT) X-Virus-Scanned: ClamAV 0.87.1/1623/Wed Jul 26 18:35:11 2006 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.0 X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on server.baldwin.cx Cc: =?utf-8?q?=E6=9D=8E=E5=B0=9A=E6=9D=B0?= Subject: Re: A bug in semctl() X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Jul 2006 17:35:18 -0000 On Wednesday 26 July 2006 03:50, =E6=9D=8E=E5=B0=9A=E6=9D=B0 wrote: > In file kern/sysv_sem.c: > 554 __semctl(td, uap) > 555 struct thread *td; > 556 struct __semctl_args *uap; > 557 { > 558 int semid =3D uap->semid; << 559 int semnum =3D uap->semnum; > 560 int cmd =3D uap->cmd; > 561 u_short *array; > 562 union semun *arg =3D uap->arg; > 563 union semun real_arg; > 564 struct ucred *cred =3D td->td_ucred; > 565 int i, rval, error; > 566 struct semid_ds sbuf; > 567 struct semid_kernel *semakptr; > 568 struct mtx *sema_mtxp; > 569 u_short usval, count; > 570 > 571 DPRINTF(("call to semctl(%d, %d, %d, 0x%x)\n", > 572 semid, semnum, cmd, arg)); > 573 if (!jail_sysvipc_allowed && jailed(td->td_ucred)) > 574 return (ENOSYS); > 575 > 576 array =3D NULL; > 577 > 578 switch(cmd) { > 579 case SEM_STAT: > 580 if (semid < 0 || semid >=3D seminfo.semmni) << 581 return (EINVAL); > 582 if ((error =3D copyin(arg, &real_arg,=20 sizeof(real_arg))) !=3D 0) > 583 return (error); > 584 semakptr =3D &sema[semid];<<=20 > >From line 558 to line 578, there must be a mechism to convert the > sem_id to the internal sema array index. In fact, it was missing, > which make the semctl syscall not work well. Actually, this is on purpose. SEM_STAT is just used for Linux binaries, an= d=20 they apparently specify a kernel semid rather than a user one for this=20 specific request. =2D-=20 John Baldwin