From owner-svn-src-head@FreeBSD.ORG Thu Sep 2 08:41:20 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C1C3F1065730; Thu, 2 Sep 2010 08:41:20 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 5A48E8FC21; Thu, 2 Sep 2010 08:41:19 +0000 (UTC) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id o828fGg7006942 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 2 Sep 2010 11:41:16 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4) with ESMTP id o828fGIw056378; Thu, 2 Sep 2010 11:41:16 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id o828fGgG056377; Thu, 2 Sep 2010 11:41:16 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Thu, 2 Sep 2010 11:41:16 +0300 From: Kostik Belousov To: David Xu Message-ID: <20100902084116.GJ2396@deviant.kiev.zoral.com.ua> References: <201009010218.o812IX5G048257@svn.freebsd.org> <20100902081136.GG2396@deviant.kiev.zoral.com.ua> <4C7FD232.9080100@freebsd.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="7SYzLFxCLxOg+UP5" Content-Disposition: inline In-Reply-To: <4C7FD232.9080100@freebsd.org> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-2.2 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_50, DNS_FROM_OPENWHOIS autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r212076 - head/lib/libthr/thread X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Sep 2010 08:41:20 -0000 --7SYzLFxCLxOg+UP5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 02, 2010 at 04:34:58PM +0000, David Xu wrote: > Kostik Belousov wrote: > >On Wed, Sep 01, 2010 at 02:18:33AM +0000, David Xu wrote: > >>Author: davidxu > >>Date: Wed Sep 1 02:18:33 2010 > >>New Revision: 212076 > >>URL: http://svn.freebsd.org/changeset/base/212076 > >> > >>Log: > >> Add signal handler wrapper, the reason to add it becauses there are > >> some cases we want to improve: > >> 1) if a thread signal got a signal while in cancellation point, > >> it is possible the TDP_WAKEUP may be eaten by signal handler > >> if the handler called some interruptibly system calls. > >> 2) In signal handler, we want to disable cancellation. > >> 3) When thread holding some low level locks, it is better to > >> disable signal, those code need not to worry reentrancy, > >> sigprocmask system call is avoided because it is a bit expensive. > >> The signal handler wrapper works in this way: > >> 1) libthr installs its signal handler if user code invokes sigaction > >> to install its handler, the user handler is recorded in internal > >> array. > >> 2) when a signal is delivered, libthr's signal handler is invoke, > >> libthr checks if thread holds some low level lock or is in criti= cal > >> region, if it is true, the signal is buffered, and all signals a= re > >> masked, once the thread leaves critical region, correct signal > >> mask is restored and buffered signal is processed. > >> 3) before user signal handler is invoked, cancellation is temporari= ly > >> disabled, after user signal handler is returned, cancellation st= ate > >> is restored, and pending cancellation is rescheduled. > > > >>+static void > >>+thr_sighandler(int sig, siginfo_t *info, void *_ucp) > >>+{ > > > >>+ if ((actp->sa_flags & SA_SIGINFO) !=3D 0) > >>+ (*(sigfunc))(sig, info, ucp); > >>+ else { > >>+ ((ohandler)(*sigfunc))( > >>+ sig, info->si_code, (struct sigcontext *)ucp, > >>+ info->si_addr, (__sighandler_t *)sigfunc); > >>+ } > > > >I do not think this is very important, but freebsd old-style signal > >handler fourth argument is usually the faulted %eip value. This is > >most likely irrelevant for any source that is linked with libthr.so > >new enough to contain this change. >=20 > Isn't the si_addr in siginfo a fault address ? I remembered I saved > the fault address in ksiginfo_t which is converted to userland > siginfo, and fault address should be there. what's wrong here ? >=20 Oops, sorry, I miscalculated the position of the arguments :(. --7SYzLFxCLxOg+UP5 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (FreeBSD) iEYEARECAAYFAkx/YywACgkQC3+MBN1Mb4i/9wCglYCkDv4JoFnRTFhmrdJXOfmx 8+8AoKhvH9n0ZUs2Co+PnmbAVS691mDx =dBtf -----END PGP SIGNATURE----- --7SYzLFxCLxOg+UP5--