| http://bugs.gentoo.org/250342 |
| http://sources.redhat.com/bugzilla/show_bug.cgi?id=9685 |
| |
| we cant assume sock_cloexec and pipe2 are bound together as the former defines |
| are found in glibc only while the latter are a combo of kernel headers and |
| glibc. so if we do a runtime detection of SOCK_CLOEXEC, but pipe2() is a stub |
| inside of glibc, we hit a problem. for example: |
| |
| #include <grp.h> |
| #include <stdio.h> |
| main() |
| { |
| getgrnam("portage"); |
| if (!popen("ls", "r")) |
| perror("popen()"); |
| } |
| |
| getgrnam() will detect that the kernel supports SOCK_CLOEXEC and then set both |
| __have_sock_cloexec and __have_pipe2 to true. but if glibc was built against |
| older kernel headers where __NR_pipe2 does not exist, glibc will have a ENOSYS |
| stub for it. so popen() will always fail as glibc assumes pipe2() works. |
| |
| diff -durN glibc-2.10.1.orig/include/unistd.h glibc-2.10.1/include/unistd.h |
| --- glibc-2.10.1.orig/include/unistd.h 2008-07-27 20:23:17.000000000 +0200 |
| +++ glibc-2.10.1/include/unistd.h 2009-11-13 00:50:15.000000000 +0100 |
| @@ -167,9 +167,6 @@ |
| extern int __pause_nocancel (void) attribute_hidden; |
| |
| extern int __have_sock_cloexec; |
| -/* At lot of other functionality became available at the same time as |
| - SOCK_CLOEXEC. Avoid defining separate variables for all of them |
| - unless it is really necessary. */ |
| -#define __have_pipe2 __have_sock_cloexec |
| +extern int __have_pipe2; |
| |
| #endif |
| diff -durN glibc-2.10.1.orig/socket/have_sock_cloexec.c glibc-2.10.1/socket/have_sock_cloexec.c |
| --- glibc-2.10.1.orig/socket/have_sock_cloexec.c 2008-07-25 18:46:23.000000000 +0200 |
| +++ glibc-2.10.1/socket/have_sock_cloexec.c 2009-11-13 00:50:15.000000000 +0100 |
| @@ -16,9 +16,14 @@ |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| +#include <fcntl.h> |
| #include <sys/socket.h> |
| #include <kernel-features.h> |
| |
| #if defined SOCK_CLOEXEC && !defined __ASSUME_SOCK_CLOEXEC |
| int __have_sock_cloexec; |
| #endif |
| + |
| +#if defined O_CLOEXEC && !defined __ASSUME_PIPE2 |
| +int __have_pipe2; |
| +#endif |