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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2018-09-19 12:14:34 -0700 |
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| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-01-03 14:38:01 -0200 |
| commit | 805334b26c7e6e83557234f2008497c72176a6cd (patch) | |
| tree | 465179b51941e1b06a2134381337d1ecf273b245 /ChangeLog | |
| parent | 03992356e6fedc5a5e9d32df96c1a2c79ea28a8f (diff) | |
| download | glibc-805334b26c7e6e83557234f2008497c72176a6cd.tar.gz glibc-805334b26c7e6e83557234f2008497c72176a6cd.tar.xz glibc-805334b26c7e6e83557234f2008497c72176a6cd.zip | |
posix: Clear close-on-exec for posix_spawn adddup2 (BZ#23640)
Austin Group issue #411 [1] proposes that posix_spawn file action posix_spawn_file_actions_adddup2 resets the close-on-exec when source and destination refer to same file descriptor. It solves the issue on multi-thread applications which uses close-on-exec as default, and want to hand-chose specifically file descriptor to purposefully inherited into a child process. Current approach to achieve this scenario is to use two adddup2 file actions and a temporary file description which do not conflict with any other, coupled with a close file action to avoid leaking the temporary file descriptor. This approach, besides being complex, may fail with EMFILE/ENFILE file descriptor exaustion. This can be more easily accomplished with an in-place removal of FD_CLOEXEC. Although the resulting adddup2 semantic is slight different than dup2 (equal file descriptors should be handled as no-op), the proposed possible solution are either more complex (fcntl action which a limited set of operations) or results in unrequired operations (dup3 which also returns EINVAL for same file descriptor). Checked on aarch64-linux-gnu. [BZ #23640] * posix/tst-spawn.c (do_prepare, handle_restart, do_test): Add posix_spawn_file_actions_adddup2 test to check O_CLOCEXEC reset. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Add close-on-exec reset for adddup2 file action. * sysdeps/posix/spawni.c (__spawni_child): Likewise. [1] http://austingroupbugs.net/view.php?id=411
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 8121c71714..f51ba49d17 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2019-01-03 Adhemerval Zanella <adhemerval.zanella@linaro.org> + + [BZ #23640] + * posix/tst-spawn.c (do_prepare, handle_restart, do_test): Add + posix_spawn_file_actions_adddup2 test to check O_CLOCEXEC reset. + * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Add + close-on-exec reset for adddup2 file action. + * sysdeps/posix/spawni.c (__spawni_child): Likewise. + 2019-01-03 Zack Weinberg <zackw@panix.com> * include/features.h (__GLIBC_USE_DEPRECATED_SCANF): New __GLIBC_USE |