From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id D8BDD1F8C6 for ; Fri, 2 Jul 2021 17:11:44 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 35075120B85; Sat, 3 Jul 2021 02:10:31 +0900 (JST) Received: from o1678948x4.outbound-mail.sendgrid.net (o1678948x4.outbound-mail.sendgrid.net [167.89.48.4]) by neon.ruby-lang.org (Postfix) with ESMTPS id E9B30120B80 for ; Sat, 3 Jul 2021 02:10:28 +0900 (JST) Received: by filterdrecv-canary-68c85d8cfd-mz96v with SMTP id filterdrecv-canary-68c85d8cfd-mz96v-1-60DF48CB-7F 2021-07-02 17:11:39.448738919 +0000 UTC m=+160227.357479187 Received: from herokuapp.com (unknown) by ismtpd0186p1mdw1.sendgrid.net (SG) with ESMTP id bHgLH1TETXW6-TORC90Mjw for ; Fri, 02 Jul 2021 17:11:39.316 +0000 (UTC) Date: Fri, 02 Jul 2021 17:11:39 +0000 (UTC) From: merch-redmine@jeremyevans.net Message-ID: References: Mime-Version: 1.0 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Bug X-Redmine-Issue-Id: 17048 X-Redmine-Issue-Author: alanwu X-Redmine-Sender: jeremyevans0 X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-Redmine-MailingListIntegration-Message-Ids: 80595 X-SG-EID: =?us-ascii?Q?RVE3t853K5scBhbmJHUzZTFFeVC=2FZSUmHZ0Dc+26wcEi2CTgsF1oz0wTSSxGGN?= =?us-ascii?Q?BIm5N2AWEpS7iJ+2AdjaP0wYEMh4JFTz7nW1s7c?= =?us-ascii?Q?8Uuhn9Itm1=2FqNbpxwQh0XUVEtK0s83Ottz5GE1S?= =?us-ascii?Q?4iQGE3DtS+fZKEoqvYcSzBegw0bMku7+lXlXRkn?= =?us-ascii?Q?Tkz40BAutSGoKKDzW+CvPWN6grT3B3h+ukvXZe5?= =?us-ascii?Q?WErXHOWmuQIjj=2F6XE=3D?= To: ruby-core@ruby-lang.org X-Entity-ID: b/2+PoftWZ6GuOu3b0IycA== X-ML-Name: ruby-core X-Mail-Count: 104475 Subject: [ruby-core:104475] [Ruby master Bug#17048] Calling initialize_copy on live modules leads to crashes X-BeenThere: ruby-core@ruby-lang.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: Ruby developers List-Id: Ruby developers List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #17048 has been updated by jeremyevans0 (Jeremy Evans). This example in the original post has been fixed recently in the master branch. I bisected the fixing commit to commit:3dd3ea092acead6179033f2c95525ffc5b8bb6ff. However, as that changes constant lookup order, I'm guessing we aren't going to want to backport it. Ruby still allows calling `Module.allocate` and calling `Module#initialize_copy` on modules with subclasses. And the example in #note-9 still can cause an occasional hang in my environment. So I'm going to leave this open. ---------------------------------------- Bug #17048: Calling initialize_copy on live modules leads to crashes https://bugs.ruby-lang.org/issues/17048#change-92735 * Author: alanwu (Alan Wu) * Status: Open * Priority: Normal * ruby -v: ruby 2.8.0dev (2020-07-23T14:44:25Z master 098e8c2873) [x86_64-linux] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- Here's a repro script ```ruby loop do m = Module.new do prepend Module.new def hello end end klass = Class.new { include m } m.send(:initialize_copy, Module.new) GC.start klass.new.hello rescue nil end ``` Here's a script that shows that it has broken semantics even when it happens to not crash. ```ruby module A end class B include A end module C Const = :C end module D Const = :D end A.send(:initialize_copy, C) p B::Const # :C, makes sense A.send(:initialize_copy, D) p B::Const # :D, makes sense A.send(:initialize_copy, Module.new) p (begin B::Const rescue NameError; 'NameError' end) # NameError, makes sense A.send(:initialize_copy, C) p B::Const # still NameErorr. Weird ``` This example shows that the problem exists [as far back as 2.0.0](https://wandbox.org/permlink/4dVDY9sNXJ803jh8). I think the easiest way to fix this is to forbid calling `:initialize_copy` on modules that have children. Another option is to try to decide on the semantics of this. Though I don't think it's worth the effort as this has been broken for a long time and people don't seem to to be using it. Thoughts? -- https://bugs.ruby-lang.org/