From d79fe162c009788888faaf0317253b6f0cac7092 Mon Sep 17 00:00:00 2001

From: Kevin Buettner <kevinb@redhat.com>

Date: Thu, 23 Apr 2020 17:05:34 -0400

Subject: [SV 58232] Disable inheritance of jobserver FDs for recursive make

A parent make will invoke a sub-make with close-on-exec disabled for

the jobserver pipe FDs.  Force close-on-exec to be to be enabled in

the sub-make so the pipe is not always passed to child jobs.

I have a test case which, when invoked with a suitable -j switch,

will hang if the recipe inherits the jobserver pipe.  This test case

was inspired by a real world case in which testing GDB on Fedora

would hang due to some poorly written test GDB cases having been

passed the jobserver file descriptors.

* src/posixos.c (jobserver_parse_auth): Call fd_noinherit() for

jobserver pipe descriptors.

Copyright-paperwork-exempt: yes

diff --git a/src/posixos.c b/src/posixos.c

index 525f292c..eab175a4 100644

--- a/src/posixos.c

+++ b/src/posixos.c

@@ -145,6 +145,11 @@ jobserver_parse_auth (const char *auth)

   /* When using pselect() we want the read to be non-blocking.  */

   set_blocking (job_fds[0], 0);

+  /* By default we don't send the job pipe FDs to our children.

+     See jobserver_pre_child() and jobserver_post_child().  */

+  fd_noinherit (job_fds[0]);

+  fd_noinherit (job_fds[1]);

+

   return 1;

 }