@@ -33,6 +33,22 @@ extern int __openat_2 (int __fd, const char *__path, int __oflag);
extern int __openat64_2 (int __fd, const char *__path, int __oflag);
+/* Makes open () & friends slightly faster on the Hurd, but can only be used
+ (without altering user-visible behavior) when we're sure that the file
+ we're opening is not (at the moment) our controlling terminal. Use this
+ when:
+ - opening well-known files internally (utmp, nss db);
+ - opening files with user-specified names that can not reasonably be ttys
+ (sem_open, shm_open);
+ - opening new (previously unused) ttys (openpty).
+ Don't use this when:
+ - doing a general-purpose open () with a user-controlled path that could
+ well be "/dev/tty" (fopen). */
+#ifndef O_IGNORE_CTTY
+# define O_IGNORE_CTTY 0
+#endif
+
+
#if IS_IN (rtld)
# include <dl-fcntl.h>
#endif
This internal definition makes it possible to use O_IGNORE_CTTY in the glibc codebase unconditionally, no matter whether the current port provides it or not (i.e. both on Hurd and on Linux). Along with the definition, this adds a small guide on when O_IGNORE_CTTY is to be used. The following commit will actually make use of O_IGNORE_CTTY throughout the glibc codebase. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> --- include/fcntl.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)