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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2016-09-16 17:44:50 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.com> | 2016-09-28 14:07:35 -0700 |
| commit | e83be730910c341f2f02ccc207b0586bb04fc21a (patch) | |
| tree | 6f8ff0de28073a7706be43359fa45fa50ea1b3f3 /sysdeps | |
| parent | 4b4d4056bb154603f36c6f8845757c1012758158 (diff) | |
| download | glibc-e83be730910c341f2f02ccc207b0586bb04fc21a.zip glibc-e83be730910c341f2f02ccc207b0586bb04fc21a.tar.gz glibc-e83be730910c341f2f02ccc207b0586bb04fc21a.tar.bz2 | |
posix: Fix open file action for posix_spawn on Linux
On posix_spawn open file action (issued by posix_spawn_file_actions_addopen)
POSIX states that if fildes was already an open file descriptor, it shall be
closed before the new file is openedi [1]. This avoid pontential issues when
posix_spawn plus addopen action is called with the process already at maximum
number of file descriptor opened and also for multiple actions on single-open
special paths (like /dev/watchdog).
This fixes its behavior on Linux posix_spawn implementation and also adds
a tests to check for its behavior.
Checked on x86_64.
* posix/Makefile (tests): Add tst-spawn3.
* posix/tst-spawn3.c: New file.
* sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Close file descriptor
if it is already opened for open action.
[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_addclose.html
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/unix/sysv/linux/spawni.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/spawni.c b/sysdeps/unix/sysv/linux/spawni.c index 679534b..fda8593 100644 --- a/sysdeps/unix/sysv/linux/spawni.c +++ b/sysdeps/unix/sysv/linux/spawni.c @@ -219,6 +219,14 @@ __spawni_child (void *arguments) case spawn_do_open: { + /* POSIX states that if fildes was already an open file descriptor, + it shall be closed before the new file is opened. This avoid + pontential issues when posix_spawn plus addopen action is called + with the process already at maximum number of file descriptor + opened and also for multiple actions on single-open special + paths (like /dev/watchdog). */ + close_not_cancel (action->action.open_action.fd); + ret = open_not_cancel (action->action.open_action.path, action->action. open_action.oflag | O_LARGEFILE, |