From: Eric Wong <normalperson@yhbt.net>
To: ruby.io.splice@librelist.org
Subject: [PATCH] set close-on-exec in pipe size modification check
Date: Sun, 21 Apr 2013 03:28:15 +0000 [thread overview]
Message-ID: <20130421032815.GA26451@dcvr.yhbt.net> (raw)
In-Reply-To: <20130421032815.GA26451@dcvr.yhbt.net>
This prevents a file descriptor leak in case another thread
forks and execs while we are in the middle of loading. This
places a hard dependency on pipe2, but pipe2 appeared in Linux
before pipe size modification.
---
ext/io_splice/extconf.rb | 1 +
ext/io_splice/io_splice_ext.c | 16 ++++++++++++++--
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/ext/io_splice/extconf.rb b/ext/io_splice/extconf.rb
index 27127c8..52dab83 100644
--- a/ext/io_splice/extconf.rb
+++ b/ext/io_splice/extconf.rb
@@ -3,6 +3,7 @@
have_func('splice', %w(fcntl.h)) or abort 'splice(2) not defined'
have_func('tee', %w(fcntl.h)) or abort 'tee(2) not defined'
+have_func('pipe2', %w(fcntl.h unistd.h))
have_func('rb_thread_blocking_region')
have_macro('F_GETPIPE_SZ', %w(fcntl.h))
have_macro('F_SETPIPE_SZ', %w(fcntl.h))
diff --git a/ext/io_splice/io_splice_ext.c b/ext/io_splice/io_splice_ext.c
index e429266..1c938c3 100644
--- a/ext/io_splice/io_splice_ext.c
+++ b/ext/io_splice/io_splice_ext.c
@@ -619,8 +619,14 @@ static VALUE set_pipe_size(VALUE self, VALUE size)
static int can_mod_pipe_size(void)
{
+ /*
+ * pipe2 appeared in Linux 2.6.27, F_*PIPE_SZ appeared in 2.6.35,
+ * thus not having pipe2 automatically disqualifies us from having
+ * F_*PIPE_SZ support
+ */
+#ifdef HAVE_PIPE2
int fds[2];
- int rc = pipe(fds);
+ int rc = pipe2(fds, O_CLOEXEC);
if (rc == 0) {
rc = fcntl(fds[0], F_GETPIPE_SZ);
@@ -629,11 +635,17 @@ static int can_mod_pipe_size(void)
(void)close(fds[0]);
(void)close(fds[1]);
} else {
- /* weird error, but don't raise during init */
+ /*
+ * weird error, but don't raise during init, this could be
+ * ENOSYS, even..
+ */
rc = 0;
}
errno = 0;
return rc;
+#else /* ! HAVE_PIPE2 */
+ return 0;
+#endif /* ! HAVE_PIPE2 */
}
void Init_io_splice_ext(void)
--
Eric Wong
parent reply other threads:[~2013-04-21 3:28 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20130421032815.GA26451@dcvr.yhbt.net>]
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