[PATCH] Restore SIGCHLD to SIG_DFL where we care about waitpid().
- From
Junio C Hamano <junkio@cox.net>
- Date
- Jun 20, 2006, 03:11 UTC
- Message-ID
- <7vslm04j2r.fsf@assigned-by-dhcp.cox.net>
- In-Reply-To
- <Pine.LNX.4.64.0606191742470.5498@g5.osdl.org>
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 <junkio@cox.net> ---
Linus Torvalds <torvalds@osdl.org> 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] <merge-program> (-a | <filename>*)");
-- 1.4.0.g275f