From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#41357: 28.0.50; GC may miss to mark calle safe register content Date: Sun, 17 May 2020 20:57:28 +0300 Message-ID: <835zcubg1j.fsf@gnu.org> References: <83pnb2bmk2.fsf@gnu.org> <83eeribiim.fsf@gnu.org> <83a726bhn1.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="49483"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 41357@debbugs.gnu.org, eggert@cs.ucla.edu To: Andrea Corallo Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun May 17 19:58:15 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jaNYD-000ClF-FG for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 17 May 2020 19:58:13 +0200 Original-Received: from localhost ([::1]:52446 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jaNYC-00048M-G1 for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 17 May 2020 13:58:12 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:36862) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jaNY2-00046i-0F for bug-gnu-emacs@gnu.org; Sun, 17 May 2020 13:58:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:33146) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jaNY1-0005WQ-Ne for bug-gnu-emacs@gnu.org; Sun, 17 May 2020 13:58:01 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jaNY1-00088D-Lr for bug-gnu-emacs@gnu.org; Sun, 17 May 2020 13:58:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 17 May 2020 17:58:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41357 X-GNU-PR-Package: emacs X-Debbugs-Original-Cc: bug-gnu-emacs@gnu.org, eggert@cs.ucla.edu Original-Received: via spool by submit@debbugs.gnu.org id=B.158973826631234 (code B ref -1); Sun, 17 May 2020 17:58:01 +0000 Original-Received: (at submit) by debbugs.gnu.org; 17 May 2020 17:57:46 +0000 Original-Received: from localhost ([127.0.0.1]:44692 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jaNXl-00087i-Qe for submit@debbugs.gnu.org; Sun, 17 May 2020 13:57:46 -0400 Original-Received: from lists.gnu.org ([209.51.188.17]:51306) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jaNXk-00087a-9V for submit@debbugs.gnu.org; Sun, 17 May 2020 13:57:44 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:36816) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jaNXj-00042B-KT for bug-gnu-emacs@gnu.org; Sun, 17 May 2020 13:57:44 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:35407) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jaNXj-0005Ui-6j; Sun, 17 May 2020 13:57:43 -0400 Original-Received: from [176.228.60.248] (port=4170 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jaNXe-00019p-9K; Sun, 17 May 2020 13:57:39 -0400 In-Reply-To: (message from Andrea Corallo on Sun, 17 May 2020 17:45:28 +0000) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:180498 Archived-At: > From: Andrea Corallo > Cc: bug-gnu-emacs@gnu.org, eggert@cs.ucla.edu > Date: Sun, 17 May 2020 17:45:28 +0000 > > Lisp_Object > foo (void) > { > /* 'res' goes in a callee saved reg */ > Lisp_Object res = build_string ("bar"); > [...] > /* LTO inline the following as "flush_stack_call_func (mark_threads_callback, NULL);" */ > mark_threads (); > [...] > gc_sweep (); > > /* The string pointed by 'res' was garbage collected. */ > return res; > } But mark_threads etc. (GC in general) isn't called from functions like your 'foo. It is more like this: Lisp_Object foo (void) { /* 'res' goes in a callee saved reg */ Lisp_Object res = build_string ("bar"); [...] call_something (); [...] } call_something (void) { [...] garbage_collect (); [...] } Which is quite different, AFAIU, wrt stack usage. Or maybe I don't understand how "callee saved registers" work.