1 http://bugs.gentoo.org/250342
2 http://sources.redhat.com/bugzilla/show_bug.cgi?id=9685
4 we cant assume sock_cloexec and pipe2 are bound together as the former defines
5 are found in glibc only while the latter are a combo of kernel headers and
6 glibc. so if we do a runtime detection of SOCK_CLOEXEC, but pipe2() is a stub
7 inside of glibc, we hit a problem. for example:
14 if (!popen("ls", "r"))
18 getgrnam() will detect that the kernel supports SOCK_CLOEXEC and then set both
19 __have_sock_cloexec and __have_pipe2 to true. but if glibc was built against
20 older kernel headers where __NR_pipe2 does not exist, glibc will have a ENOSYS
21 stub for it. so popen() will always fail as glibc assumes pipe2() works.
24 include/unistd.h | 5 +----
25 socket/have_sock_cloexec.c | 5 +++++
26 2 files changed, 6 insertions(+), 4 deletions(-)
28 --- a/include/unistd.h
29 +++ b/include/unistd.h
31 extern int __pause_nocancel (void) attribute_hidden;
33 extern int __have_sock_cloexec;
34 -/* At lot of other functionality became available at the same time as
35 - SOCK_CLOEXEC. Avoid defining separate variables for all of them
36 - unless it is really necessary. */
37 -#define __have_pipe2 __have_sock_cloexec
38 +extern int __have_pipe2;
42 --- a/socket/have_sock_cloexec.c
43 +++ b/socket/have_sock_cloexec.c
45 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
49 #include <sys/socket.h>
50 #include <kernel-features.h>
52 #if defined SOCK_CLOEXEC && !defined __ASSUME_SOCK_CLOEXEC
53 int __have_sock_cloexec;
56 +#if defined O_CLOEXEC && !defined __ASSUME_PIPE2