From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.2 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by inbox.vuxu.org (OpenSMTPD) with SMTP id 0ab1e9b2 for ; Fri, 31 Jan 2020 16:35:22 +0000 (UTC) Received: (qmail 13832 invoked by uid 550); 31 Jan 2020 16:35:21 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 13814 invoked from network); 31 Jan 2020 16:35:20 -0000 Date: Fri, 31 Jan 2020 11:35:08 -0500 From: Rich Felker To: musl@lists.openwall.com Message-ID: <20200131163508.GH1663@brightrain.aerifal.cx> References: <20200129191946.GI2020@voyager> <20200130170249.GK2020@voyager> <20200131042431.GC1663@brightrain.aerifal.cx> <20200131144748.GL2020@voyager> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200131144748.GL2020@voyager> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: Rich Felker Subject: Re: [musl] Static linking is broken after creation of DT_TEXTREL segment On Fri, Jan 31, 2020 at 03:47:48PM +0100, Markus Wichmann wrote: > > Assuming this is at startup, that's not a possibility; no application > > code has run yet. > > Unfortunately, signal mask and ignore dispositions are inherited across > execve(). A tool that ignores or blocks specific signals before execing > the rest of its command line is therefore possible. I seem to remember > such a tool, but cannot remember its name. A cursory search on the > Internet failed to turn up anything. For synchronously-generated SIGSEGV or SIGILL from faults, all that ignoring or blocking them does is ensure that a handler can't run and that they terminate the process (this is implementation-specific but a Linux contract and The Right Thing to do). Signal handlers of course cannot be inherited across exec; they revert to SIG_DFL. Rich