From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Florian Weimer Newsgroups: gmane.comp.lib.glibc.alpha Subject: Re: [PATCH 0/2] nptl: Update struct pthread_unwind_buf Date: Thu, 08 Feb 2018 12:55:04 +0100 Message-ID: <87inb7pug7.fsf@mid.deneb.enyo.de> References: <20180201205757.51911-1-hjl.tools@gmail.com> <4abf9786-1879-f16c-5a01-3261cd718d63@redhat.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1518090806 13786 195.159.176.226 (8 Feb 2018 11:53:26 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 8 Feb 2018 11:53:26 +0000 (UTC) Cc: "H.J. Lu" , libc-alpha@sourceware.org To: Carlos O'Donell Original-X-From: libc-alpha-return-90140-glibc-alpha=m.gmane.org@sourceware.org Thu Feb 08 12:53:22 2018 Return-path: Envelope-to: glibc-alpha@blaine.gmane.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:references:date:in-reply-to :message-id:mime-version:content-type; q=dns; s=default; b=ZxmUt K615QHNsqmZUAbNTZxF25bl0Jxynoa3tJdG7KsI47R5gT+mw1tlWLAXX3nHWWr/B m1LllooYuSyvlxey2e+lJpKl6LzBi4RsKBpkevM0AfivNfNoFZNMOa+eFAFYu+jR f5AtaQWvHiflj5ieYBFD3oCOw55gBz/XlPuPO8= 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:from:to:cc:subject:references:date:in-reply-to :message-id:mime-version:content-type; s=default; bh=17wsvSxViLg LDVkCgybaKBhccYo=; b=r1spVVTMcCd1HBjgSO4kQX905P1iwVsU1lqzf6YgOdq aHt9N8balTYLuVxMyKzoIA8HJduzJ2N0pO4FfRjIXG4iaQPYHSDgRGBzvG46Jbl/ gUn0xY09YiQWYMU5lf/Xj+iX5wkWtY2o0P3jfPk1ra/Mq78xAR8qTiQmCQZqXKmw = Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Original-Sender: libc-alpha-owner@sourceware.org Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.0 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 spammy= X-HELO: albireo.enyo.de In-Reply-To: <4abf9786-1879-f16c-5a01-3261cd718d63@redhat.com> (Carlos O'Donell's message of "Thu, 8 Feb 2018 01:25:24 -0800") Xref: news.gmane.org gmane.comp.lib.glibc.alpha:82488 Archived-At: Received: from server1.sourceware.org ([209.132.180.131] helo=sourceware.org) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ejklO-0002sq-2L for glibc-alpha@blaine.gmane.org; Thu, 08 Feb 2018 12:53:14 +0100 Received: (qmail 93945 invoked by alias); 8 Feb 2018 11:55:10 -0000 Received: (qmail 93806 invoked by uid 89); 8 Feb 2018 11:55:10 -0000 * Carlos O'Donell: > I would like to see an argument made for CET markup against versioning > __pthread_register_cleanup. I don't think __pthread_register_cleanup. It's __sigsetjmp. We would have to version __sigsetjmp. Changing the name would be ideal, but this will be difficult because of its returns-twice nature. I also don't have a problem with requiring -fexceptions for cancellation handlers with CET support. For additional safety, we could change sigsetjmp to write the shadow stack pointer before the kernel signal mask, so that it will still be in bounds for legacy cancellation handler allocation. __pthread_register_cleanup will overwrite it, but I don't think we ever need to restore it, so that shouldn't be a problem.