[PATCH glibc 2/3] hurd: __adjtime(): struct timeval and time_value_t are not identical.

[Michael Kelly]

'struct timeval' and 'struct time_value' have different types for the
microseconds component: int and long int. Casting one to the other
leads to negative numbers not being preserved properly within the
called code.
---
 sysdeps/mach/hurd/adjtime.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/sysdeps/mach/hurd/adjtime.c b/sysdeps/mach/hurd/adjtime.c
index c25b666a22..e9c0851daa 100644
--- a/sysdeps/mach/hurd/adjtime.c
+++ b/sysdeps/mach/hurd/adjtime.c
@@ -28,24 +28,35 @@ __adjtime (const struct timeval *delta, struct timeval 
*olddelta)
 {
   error_t err;
   mach_port_t hostpriv;
-  struct timeval dummy;
+  time_value_t rpc_delta, rpc_olddelta;
 
   err = __get_privileged_ports (&hostpriv, NULL);
   if (err)
     return __hurd_fail (EPERM);
 
-  if (olddelta == NULL)
-    olddelta = &dummy;
+  if (delta != NULL)
+    {
+      rpc_delta.seconds = delta->tv_sec;
 
-  err = __host_adjust_time (hostpriv,
-                           /* `time_value_t' and `struct timeval' are in
-                               fact identical with the names changed.  */
-                           *(time_value_t *) delta,
-                           (time_value_t *) olddelta);
+      /* Handle overflow if microsecond types differ. */
+      rpc_delta.microseconds = (delta->tv_usec % TIME_MICROS_MAX);
+      rpc_delta.seconds += (delta->tv_usec / TIME_MICROS_MAX);
+    }
+  else
+    return EINVAL;
+
+  err = __host_adjust_time (hostpriv, rpc_delta, &rpc_olddelta);
   __mach_port_deallocate (__mach_task_self (), hostpriv);
 
   if (err)
     return __hurd_fail (err);
+
+  if (olddelta != NULL)
+    {
+      olddelta->tv_sec = rpc_olddelta.seconds;
+      olddelta->tv_usec = rpc_olddelta.microseconds;
+    }
+
   return 0;
 }
 
-- 
2.47.3