From owner-cvs-all@FreeBSD.ORG Thu Jun 10 21:34:57 2004 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DBBEE16A4CE; Thu, 10 Jun 2004 21:34:57 +0000 (GMT) Received: from repoman.freebsd.org (repoman.freebsd.org [216.136.204.115]) by mx1.FreeBSD.org (Postfix) with ESMTP id D6DDD43D48; Thu, 10 Jun 2004 21:34:57 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from repoman.freebsd.org (localhost [127.0.0.1]) by repoman.freebsd.org (8.12.11/8.12.11) with ESMTP id i5ALYc2A004705; Thu, 10 Jun 2004 21:34:38 GMT (envelope-from rwatson@repoman.freebsd.org) Received: (from rwatson@localhost) by repoman.freebsd.org (8.12.11/8.12.11/Submit) id i5ALYcNr004704; Thu, 10 Jun 2004 21:34:38 GMT (envelope-from rwatson) Message-Id: <200406102134.i5ALYcNr004704@repoman.freebsd.org> From: Robert Watson Date: Thu, 10 Jun 2004 21:34:38 +0000 (UTC) To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org X-FreeBSD-CVS-Branch: HEAD Subject: cvs commit: src/sys/kern uipc_usrreq.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Jun 2004 21:34:58 -0000 rwatson 2004-06-10 21:34:38 UTC FreeBSD src repository Modified files: sys/kern uipc_usrreq.c Log: Introduce a subsystem lock around UNIX domain sockets in order to protect global and allocated variables. This strategy is derived from work originally developed by BSDi for BSD/OS, and applied to FreeBSD by Sam Leffler: - Add unp_mtx, a global mutex which will protect all UNIX domain socket related variables, structures, etc. - Add UNP_LOCK(), UNP_UNLOCK(), UNP_LOCK_ASSERT() macros. - Acquire unp_mtx on entering most UNIX domain socket code, drop/re-acquire around calls into VFS, and release it on return. - Avoid performing sodupsockaddr() while holding the mutex, so in general move to allocating storage before acquiring the mutex to copy the data. - Make a stack copy of the xucred rather than copying out while holding unp_mtx. Copy the peer credential out after releasing the mutex. - Add additional assertions of vnode locks following VOP_CREATE(). A few notes: - Use of an sx lock for the file list mutex may cause problems with regard to unp_mtx when garbage collection passed file descriptors. - The locking in unp_pcblist() for sysctl monitoring is correct subject to the unpcb zone not returning memory for reuse by other subsystems (consistent with similar existing concerns). - Sam's version of this change, as with the BSD/OS version, made use of both a global lock and per-unpcb locks. However, in practice, the global lock covered all accesses, so I have simplified out the unpcb locks in the interest of getting this merged faster (reducing the overhead but not sacrificing granularity in most cases). We will want to explore possibilities for improving lock granularity in this code in the future. Submitted by: sam Sponsored by: FreeBSD Foundatiuon Obtained from: BSD/OS 5 snapshot provided by BSDi Revision Changes Path 1.122 +193 -58 src/sys/kern/uipc_usrreq.c