provide stime and settimeofday functions if at least one of the syscalls is available

Add hidden stime for possible use in settimeofday.
Add stubs for both functions if none of the syscalls is present.
Avoid circular dependency.

Signed-off-by: Peter S. Mazinger <ps.m@gmx.net>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

include/time.h

@@ -318,6 +318,7 @@ extern long int timezone;
 /* Set the system time to *WHEN.
    This call is restricted to the superuser.  */
 extern int stime (__const time_t *__when) __THROW;
+libc_hidden_proto(stime)
 # endif
 
 

libc/sysdeps/linux/common/settimeofday.c

@@ -8,12 +8,36 @@
  */
 
 #include <sys/syscall.h>
-#include <sys/time.h>
 
 #ifdef __USE_BSD
+# include <sys/time.h>
+# ifdef __NR_settimeofday
+_syscall2(int, settimeofday, const struct timeval *, tv,
+	  const struct timezone *, tz)
+# elif defined __USE_SVID && defined __NR_stime
+#  define __need_NULL
+#  include <stddef.h>
+#  include <errno.h>
+#  include <time.h>
+int settimeofday(const struct timeval *tv, const struct timezone *tz)
+{
+	time_t when;
 
+	if (tv == NULL) {
+		__set_errno(EINVAL);
+		return -1;
+	}
 
-_syscall2(int, settimeofday, const struct timeval *, tv,
-		  const struct timezone *, tz)
+	if (tz != NULL || tv->tv_usec % 1000000 != 0) {
+		__set_errno(ENOSYS);
+		return -1;
+	}
+
+	when = tv->tv_sec + (tv->tv_usec / 1000000);
+	return stime(&when);
+}
+# endif
+# if defined __NR_settimeofday || (defined __USE_SVID && defined __NR_stime)
 libc_hidden_def(settimeofday)
+# endif
 #endif

libc/sysdeps/linux/common/stime.c

@@ -8,15 +8,17 @@
  */
 
 #include <sys/syscall.h>
-#include <time.h>
-#include <sys/time.h>
 
 #ifdef __USE_SVID
-#ifdef __NR_stime
+# include <time.h>
+# ifdef __NR_stime
 _syscall1(int, stime, const time_t *, t)
-#else
-
-int stime(const time_t * when)
+# elif defined __USE_BSD && defined __NR_settimeofday
+#  define __need_NULL
+#  include <stddef.h>
+#  include <errno.h>
+#  include <sys/time.h>
+int stime(const time_t *when)
 {
 	struct timeval tv;
 
@@ -28,5 +30,8 @@ int stime(const time_t * when)
 	tv.tv_usec = 0;
 	return settimeofday(&tv, (struct timezone *) 0);
 }
-#endif
+# endif
+# if defined __NR_stime || (defined __USE_BSD && defined __NR_settimeofday)
+libc_hidden_def(stime)
+# endif
 #endif