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

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e1ca9dea05d879c69cc9772253382f77efe627ef

commit e1ca9dea05d879c69cc9772253382f77efe627ef
Author: Michael Kelly <[email protected]>
Date:   Wed Apr 15 22:18:52 2026 +0200

    hurd: __adjtime(): struct timeval and time_value_t are not identical.
    
    '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.
    Message-ID: <[email protected]>

Diff:
---
 sysdeps/mach/hurd/adjtime.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/sysdeps/mach/hurd/adjtime.c b/sysdeps/mach/hurd/adjtime.c
index 915b86da13..9d01533b23 100644
--- a/sysdeps/mach/hurd/adjtime.c
+++ b/sysdeps/mach/hurd/adjtime.c
@@ -28,31 +28,36 @@ __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)
     {
       if (delta->tv_usec >=  TIME_MICROS_MAX ||
           delta->tv_usec <= -TIME_MICROS_MAX)
        return EINVAL;
+
+      rpc_delta.seconds = delta->tv_sec;
+      rpc_delta.microseconds = delta->tv_usec;
     }
+  else
+    return EINVAL;
 
-  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);
+  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;
 }