Re: [alsa-devel] [PATCH 1/3] Open device nodes with close-on-exec flag

On Wed, 04.11.09 20:38, Rémi Denis-Courmont (remi@remlab.net) wrote:

static inline int snd_open_device(const char *filename, int fmode) {

• int fd = open(filename, fmode);

• int fd;

+#ifdef O_CLOEXEC

• fd = open(filename, fmode|O_CLOEXEC); if (fd >= 0) return fd;
• if (errno == EINVAL)

+#endif

• {

• fd = open(filename, fmode);
  

• if (fd >= 0) {
  

• 	fcntl(fd, F_SETFD, FD_CLOEXEC);
  

• 	return fd;
  

• }
  

That's actually not how things works. O_CLOEXEC is silently ignored by old kernels. (The calls with SOCK_CLOEXEC fail with EINVAL while the calls with O_CLOEXEC silently succeed) You need to set FD_CLOEXEC unconditionally to cover all cases:

fd = open(fn, fmode #ifdef O_CLOEXEC |O_CLOEXEC #endif ); fcntl(fd, F_SETFD, FD_CLOEXEC);

Lennart