delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2015/06/22/10:31:24

X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:reply-to:date:from:to:subject:message-id
:mime-version:content-type; q=dns; s=default; b=Xo2tusl3zJiUCHRw
eoNNKbG0GtAb5LMABFiiGG10pG4a/nX9fWimDACAx6aMLUoCy1/WFLC4jo5bKGn0
fwqF0h+98nE4dDwR+9dYKuLcWx9i40bB4xkbWyzG83MoupBNNLcugTh+V8F2oCYe
tskwk6M1qVDMGoGoMuDiFuT2tiM=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:reply-to:date:from:to:subject:message-id
:mime-version:content-type; s=default; bh=ypN1/mexKnoTH3tux2v7Xz
4zU5A=; b=wH6KTqhl5WNx6Ih9pwYcmBHpFXGxgf/Uf3FwLExN9S+NJoP0utNFok
3s3B2nzYpOgb9NqW0H3YNbpaCVqXLLFIWbc1ajfpqP8ykT9CWyG1sscWLB7rtkur
SjWhjsSeSduSi+/o+jeSELxAwdpx4lA/B6M97RJa34xWTBTk4qFjk=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.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
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-HELO: localhost.localdomain
Reply-To: cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-2.8 required=5.0 tests=AWL,BAYES_50,EXECUTABLE_URI,KAM_EXEURI,KAM_LAZY_DOMAIN_SECURITY autolearn=no version=3.3.2
Date: Mon, 22 Jun 2015 14:55:18 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: [ANNOUNCEMENT] TEST RELEASE: Cygwin 2.1.0-0.2
Message-Id: <announce.20150622125518.GF28301@calimero.vinschen.de>
MIME-Version: 1.0
User-Agent: Mutt/1.5.23 (2014-03-12)

Hi Cygwin friends and users,


I released a second TEST version of Cygwin.  The version number is
2.1.0-0.2.

This test release is mostly for interested *developers*.

The important news which needs some testing is the implementation of
sigaltstack(2) and the underlying implementation of running a signal
handler on the alternate signal stack.

Two changes to the previous test release, a fix to the sys/signal.h
header file which potentially broke building, and a change in the
assembler code preparing the alternate stack for the signal handler.

Implementation details:

- The alternate signal stack installed via sigaltstack is only valid for
  the current thread.  Each thread must call its own sigaltstack.  On
  pthread_create, the alternate signal stack setting of the calling
  thread is *not* propagated to the newly created thread.  This follows
  current Linux semantics.

- The alternate signal stack is a minimal stack.  Certain datastructures
  used by Cygwin (_cygtls area) and Windows (on 32 bit: exception
  records) are not copied over to the alternate signal stack.  The stack
  settings in the Thread Environment Block (TEB) are not reflecting the
  current alternate stack while running the signal handler.  The TEB
  will still point to the original thread stack.  This seems to work
  nicely in my testing, but there may be Windows functions which stop
  working in this scenario.

- The volatile registers and the original stack registers are stored at
  the base of the alternate stack.  If you screw this up while running
  the signal handler, your thread is doomed on return to the caller.

I'd be grateful if curious developers would give this new sigaltstack
implementation a whirl and report back if it's working for them as
desired/expected.  And if not, simple reproducers in plain C are most
welcome in this case.  Discussing aspects of this implementation may be
best handled on the cygwin-developers mailing list or the
#cygwin-developers IRC channel on Freenode.


All changes in this release so far:
===================================

What's new:
-----------

- First cut of an implementation to allow signal handlers running on an
  alternate signal stack.
  
- New API sigaltstack, plus definitions for SA_ONSTACK, SS_ONSTACK, SS_DISABLE,
  MINSIGSTKSZ, SIGSTKSZ.

- New API: sethostname.


Bug Fixes
---------

- Enable non-SA_RESTART behaviour on threads other than main thread.
  Addresses: https://cygwin.com/ml/cygwin/2015-06/msg00260.html

- Try to handle concurrent close on socket more gracefully
  Addresses: https://cygwin.com/ml/cygwin/2015-06/msg00235.html


To install 32-bit Cygwin use https://cygwin.com/setup-x86.exe
To install 64 bit Cygwin use https://cygwin.com/setup-x86_64.exe


Have fun,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--
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

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019