delorie.com/archives/browse.cgi | search |
X-Recipient: | archive-cygwin AT delorie DOT com |
X-SWARE-Spam-Status: | No, hits=-1.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,UNPARSEABLE_RELAY |
X-Spam-Check-By: | sourceware.org |
X-Yahoo-SMTP: | jenXL62swBAWhMTL3wnej93oaS0ClBQOAKs8jbEbx_o- |
Date: | Thu, 8 Sep 2011 10:27:02 -0400 |
From: | Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com> |
To: | cygwin AT cygwin DOT com |
Subject: | Re: debugging SIGSEV on pclose |
Message-ID: | <20110908142702.GA28918@ednor.casa.cgf.cx> |
Reply-To: | cygwin AT cygwin DOT com |
Mail-Followup-To: | cygwin AT cygwin DOT com |
References: | <4E64BE96 DOT 5020107 AT gmail DOT com> <4E68CE13 DOT 6010106 AT gmail DOT com> |
MIME-Version: | 1.0 |
In-Reply-To: | <4E68CE13.6010106@gmail.com> |
User-Agent: | Mutt/1.5.20 (2009-06-14) |
Mailing-List: | contact cygwin-help AT cygwin DOT com; run by ezmlm |
List-Id: | <cygwin.cygwin.com> |
List-Unsubscribe: | <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com> |
List-Subscribe: | <mailto:cygwin-subscribe AT cygwin DOT com> |
List-Archive: | <http://sourceware.org/ml/cygwin/> |
List-Post: | <mailto:cygwin AT cygwin DOT com> |
List-Help: | <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs> |
Sender: | cygwin-owner AT cygwin DOT com |
Mail-Followup-To: | cygwin AT cygwin DOT com |
Delivered-To: | mailing list cygwin AT cygwin DOT com |
On Thu, Sep 08, 2011 at 04:15:47PM +0200, Marco atzeri wrote: >On 9/5/2011 2:20 PM, Marco atzeri wrote: >> Hi, >> I am trying to identify the octave segfault, last reported on >> http://cygwin.com/ml/cygwin-announce/2011-08/msg00003.html >> >> To reproduce: run octave from xterm and at prompt >> ------------------------- >> graphics_toolkit ("fltk") >> x=1:10; >> plot(x,x) >> print("fltk.png","-dpng") >> ------------------------- >> the plot is built and printed as file but octave crashes. >> >> >> After builiding cygwin (cvs), octave and fltk with >> gcc-4.5.3 I was able to identify the SIGSEV in cygwin pclose. >> >> Program received signal SIGSEGV, Segmentation fault. >> [Switching to Thread 5980.0x164c] >> pclose (fp=0x7ffdf000) at >> /pub/cygwin/cvs/src_new/winsup/cygwin/syscalls.cc:4026 >> 4026 if (fh->get_device () != FH_PIPEW && fh->get_device () != FH_PIPER) >> (gdb) l >> 4021 int >> 4022 pclose (FILE *fp) >> 4023 { >> 4024 fhandler_pipe *fh = (fhandler_pipe *) cygheap->fdtab[fileno(fp)]; > >Answering myself while kicking the head on the wall > >the SIGSEV on 4026 is obvious as fh is NULL > >(gdb) p fh >$7 = (fhandler_pipe *) 0x0 >(gdb) p fp >$8 = (FILE *) 0x20204f94 > >> 4025 >> 4026 if (fh->get_device () != FH_PIPEW && fh->get_device () != FH_PIPER) > >Question: >is a mistake in pclose to assume that fh could be invalid I'm not sure what you're asking here. It's not a mistake to assume that pclose is being passed a valid fp. Linux also crashes if the fp is closed twice. >or something is just trashing cygheap->fdtab ? Who knows? strace should show if the fp is closed twice. cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
webmaster | delorie software privacy |
Copyright © 2019 by DJ Delorie | Updated Jul 2019 |