From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: [PATCH] Restore SIGCHLD to SIG_DFL where we care about waitpid(). Date: Mon, 19 Jun 2006 20:11:40 -0700 Message-ID: <7vslm04j2r.fsf@assigned-by-dhcp.cox.net> References: <7vwtbc7ll6.fsf@assigned-by-dhcp.cox.net> <7vfyi07jf2.fsf@assigned-by-dhcp.cox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Tue Jun 20 05:11:47 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1FsWeY-0001tw-SW for gcvg-git@gmane.org; Tue, 20 Jun 2006 05:11:47 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965249AbWFTDLn (ORCPT ); Mon, 19 Jun 2006 23:11:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965253AbWFTDLn (ORCPT ); Mon, 19 Jun 2006 23:11:43 -0400 Received: from fed1rmmtao02.cox.net ([68.230.241.37]:23691 "EHLO fed1rmmtao02.cox.net") by vger.kernel.org with ESMTP id S965249AbWFTDLm (ORCPT ); Mon, 19 Jun 2006 23:11:42 -0400 Received: from assigned-by-dhcp.cox.net ([68.4.9.127]) by fed1rmmtao02.cox.net (InterMail vM.6.01.06.01 201-2131-130-101-20060113) with ESMTP id <20060620031141.QCOL12581.fed1rmmtao02.cox.net@assigned-by-dhcp.cox.net>; Mon, 19 Jun 2006 23:11:41 -0400 To: Linus Torvalds User-Agent: Gnus/5.110004 (No Gnus v0.4) Emacs/21.4 (gnu/linux) Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: It was reported that under one implementation of socks client, "git clone" fails with "error: waitpid failed (No child processes)", because "git" is spawned after setting SIGCHLD to SIG_IGN. Arguably it may be a broken setting, but we should protect ourselves so that we can get reliable results from waitpid() for the children we care about. This patch resets SIGCHLD to SIG_DFL in three places: - connect.c::git_connect() - initiators of git native protocol transfer are covered with this. - daemon.c::main() - obviously. - merge-index.c::main() - obviously. There are other programs that do fork() but do not waitpid(): http-push, imap-send. upload-pack does not either, but in the case of that program, each of the forked halves runs exec() another program, so this change would not have much effect there. Signed-off-by: Junio C Hamano --- Linus Torvalds writes: > On Mon, 19 Jun 2006, Junio C Hamano wrote: > >> I do not offhand think of a place where we do fork() but not >> waitpid(), and it is very tempting to cheat and do that in the >> main(), since I do not see a downside to it. > > Yeah, it probably does make sense. That said, there are several "main()" > functions, so you'd still end up having to verify that we catch all the > paths.. Are all users of fork() built-in by now? Not really. But git native protocol initiators all use git_connect() so they are easy, and there are only few remaining ones that matter. connect.c | 5 +++++ daemon.c | 5 +++++ merge-index.c | 5 +++++ 3 files changed, 15 insertions(+), 0 deletions(-) diff --git a/connect.c b/connect.c index 52d709e..db7342e 100644 --- a/connect.c +++ b/connect.c @@ -581,6 +581,11 @@ int git_connect(int fd[2], char *url, co enum protocol protocol = PROTO_LOCAL; int free_path = 0; + /* Without this we cannot rely on waitpid() to tell + * what happened to our children. + */ + signal(SIGCHLD, SIG_DFL); + host = strstr(url, "://"); if(host) { *host = '\0'; diff --git a/daemon.c b/daemon.c index 2f03f99..1067004 100644 --- a/daemon.c +++ b/daemon.c @@ -671,6 +671,11 @@ int main(int argc, char **argv) int inetd_mode = 0; int i; + /* Without this we cannot rely on waitpid() to tell + * what happened to our children. + */ + signal(SIGCHLD, SIG_DFL); + for (i = 1; i < argc; i++) { char *arg = argv[i]; diff --git a/merge-index.c b/merge-index.c index 024196e..190e12f 100644 --- a/merge-index.c +++ b/merge-index.c @@ -99,6 +99,11 @@ int main(int argc, char **argv) { int i, force_file = 0; + /* Without this we cannot rely on waitpid() to tell + * what happened to our children. + */ + signal(SIGCHLD, SIG_DFL); + if (argc < 3) usage("git-merge-index [-o] [-q] (-a | *)"); -- 1.4.0.g275f