From abb3587fe939d469a44f2097bae361aabd269f3f Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 5 Sep 2009 22:04:36 +0200 Subject: CLOEXEC: use open(CLOEXEC) if exist; do not check fcntl(FD_CLOEXEC) failure text data bss dec hex filename - 370 0 0 370 172 libc/misc/dirent/opendir.o + 366 0 0 366 16e libc/misc/dirent/opendir.o - 375 4 0 379 17b libc/pwd_grp/lckpwdf.o + 356 4 0 360 168 libc/pwd_grp/lckpwdf.o - 248 0 0 248 f8 librt/shm.o + 209 0 0 209 d1 librt/shm.o Signed-off-by: Denys Vlasenko --- libc/pwd_grp/lckpwdf.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) (limited to 'libc/pwd_grp') diff --git a/libc/pwd_grp/lckpwdf.c b/libc/pwd_grp/lckpwdf.c index c0c8f0d90..68c46e02c 100644 --- a/libc/pwd_grp/lckpwdf.c +++ b/libc/pwd_grp/lckpwdf.c @@ -28,17 +28,6 @@ #include #include -/* Experimentally off - libc_hidden_proto(memset) */ -/* libc_hidden_proto(open) */ -/* libc_hidden_proto(fcntl) */ -/* libc_hidden_proto(close) */ -/* libc_hidden_proto(sigfillset) */ -/* libc_hidden_proto(sigaction) */ -/* libc_hidden_proto(sigprocmask) */ -/* libc_hidden_proto(sigaddset) */ -/* libc_hidden_proto(sigemptyset) */ -/* libc_hidden_proto(alarm) */ - /* How long to wait for getting the lock before returning with an error. */ #define TIMEOUT 15 /* sec */ @@ -56,7 +45,6 @@ static void noop_handler (int __sig); int lckpwdf (void) { - int flags; sigset_t saved_set; /* Saved set of caught signals. */ struct sigaction saved_act; /* Saved signal action. */ sigset_t new_set; /* New set of caught signals. */ @@ -72,16 +60,18 @@ lckpwdf (void) /* Prevent problems caused by multiple threads. */ __UCLIBC_MUTEX_LOCK(mylock); - lock_fd = open (_PATH_PASSWD, O_WRONLY); +#ifndef O_CLOEXEC +# define O_CLOEXEC 0 +#endif + lock_fd = open (_PATH_PASSWD, O_WRONLY | O_CLOEXEC); if (lock_fd == -1) { /* Cannot create lock file. */ - goto DONE; + goto DONE; } - /* Make sure file gets correctly closed when process finished. */ - flags = fcntl (lock_fd, F_GETFD); - flags |= FD_CLOEXEC; - fcntl (lock_fd, F_SETFD, flags); + if (O_CLOEXEC == 0) + fcntl (lock_fd, F_SETFD, FD_CLOEXEC); + /* Now we have to get exclusive write access. Since multiple process could try this we won't stop when it first fails. Instead we set a timeout for the system call. Once the timer @@ -91,7 +81,7 @@ lckpwdf (void) It is important that we don't change the signal state. We must restore the old signal behaviour. */ - memset (&new_act, '\0', sizeof (struct sigaction)); + memset (&new_act, '\0', sizeof (new_act)); new_act.sa_handler = noop_handler; __sigfillset (&new_act.sa_mask); @@ -125,7 +115,7 @@ lckpwdf (void) if (result < 0) { close(lock_fd); lock_fd = -1; - goto DONE; + goto DONE; } rv = 0; @@ -146,7 +136,7 @@ ulckpwdf (void) else { /* Prevent problems caused by multiple threads. */ - __UCLIBC_MUTEX_LOCK(mylock); + __UCLIBC_MUTEX_LOCK(mylock); result = close (lock_fd); @@ -154,7 +144,7 @@ ulckpwdf (void) lock_fd = -1; /* Clear mutex. */ - __UCLIBC_MUTEX_UNLOCK(mylock); + __UCLIBC_MUTEX_UNLOCK(mylock); } return result; -- cgit v1.2.3