[PATCH] libc_r bug: successful close(2) sets errno to ENOTTY

[Enache Adrian]

$ cc close.c -o close && ./close
0
0

$ cc close.c -lc_r -o close && ./close
0
25

$ cat close.c
#include <errno.h>
main()
{
        int fd = open("/dev/null", 1);
        printf("%d\n", errno);
        close(fd);
        printf("%d\n", errno);
}

This confuses rather badly applications which assume errno is meaningful.
It could be fixed easily by repeating the trick from uthread/uthread_fd.c:

--- /arc/freebsd/src/lib/libc_r/uthread/uthread_close.c Tue Jun 10 23:42:27 2003
+++ lib/libc_r/uthread/uthread_close.c  Sun Nov 23 00:50:30 2003
@@ -87,10 +87,12 @@ _close(int fd)
                 */
                if ((S_ISREG(sb.st_mode) || S_ISCHR(sb.st_mode))
                    && (_thread_fd_getflags(fd) & O_NONBLOCK) == 0) {
+                       int saved_errno = errno;
                        /* Get the current flags: */
                        flags = __sys_fcntl(fd, F_GETFL, NULL);
                        /* Clear the nonblocking file descriptor flag: */
                        __sys_fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
+                       errno = saved_errno;
                }
 
                /* XXX: Assumes well behaved threads. */

Regards,
Adi
_______________________________________________
[EMAIL PROTECTED] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "[EMAIL PROTECTED]"