* sysdeps/unix/sysv/linux/adjtime.c: Use ADJ_OFFSET_SS_READ if

	possible.
	* sysdeps/unix/sysv/linux/kernel-features.h
	(__ASSUME_ADJ_OFFSET_SS_READ): Define for 2.6.24.
	* sysdeps/unix/sysv/linux/sys/timex.h (ADJ_OFFSET_SS_READ): Define.

diff --git a/ChangeLog b/ChangeLog
index 560a6e6..c94d0e4 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2007-12-10  Ulrich Drepper  <drepper@redhat.com>
+
+       * sysdeps/unix/sysv/linux/adjtime.c: Use ADJ_OFFSET_SS_READ if
+       possible.
+       * sysdeps/unix/sysv/linux/kernel-features.h
+       (__ASSUME_ADJ_OFFSET_SS_READ): Define for 2.6.24.
+       * sysdeps/unix/sysv/linux/sys/timex.h (ADJ_OFFSET_SS_READ): Define.
+
 2007-12-08  Ulrich Drepper  <drepper@redhat.com>
 
        [BZ #5424]

diff --git a/sysdeps/unix/sysv/linux/adjtime.c b/sysdeps/unix/sysv/linux/adjtime.c
index 38ef805..202bb14 100644 (file)
--- a/sysdeps/unix/sysv/linux/adjtime.c
+++ b/sysdeps/unix/sysv/linux/adjtime.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995, 1996, 1997, 1998, 2002, 2004
+/* Copyright (C) 1995, 1996, 1997, 1998, 2002, 2004, 2007
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -22,6 +22,8 @@
 #include <sys/time.h>
 #include <sys/timex.h>
 
+#include <kernel-features.h>
+
 #define MAX_SEC        (INT_MAX / 1000000L - 2)
 #define MIN_SEC        (INT_MIN / 1000000L + 2)
 
@@ -69,13 +71,29 @@ ADJTIME (const struct TIMEVAL *itv, struct TIMEVAL *otv)
          return -1;
        }
       tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
+#ifdef ADJ_OFFSET_SS_READ
+      tntx.modes = ADJ_OFFSET_SS_READ;
+#else
       tntx.modes = ADJ_OFFSET_SINGLESHOT;
+#endif
     }
   else
     tntx.modes = 0;
 
-  if (ADJTIMEX (&tntx) < 0)
-    return -1;
+#if defined ADJ_OFFSET_SS_READ && !defined __ASSUME_ADJ_OFFSET_SS_READ
+ again:
+#endif
+  if (__builtin_expect (ADJTIMEX (&tntx) < 0, 0))
+    {
+#if defined ADJ_OFFSET_SS_READ && !defined __ASSUME_ADJ_OFFSET_SS_READ
+      if (itv && errno == EINVAL && tntx.modes == ADJ_OFFSET_SS_READ)
+       {
+         tntx.modes = ADJ_OFFSET_SINGLESHOT;
+         goto again;
+       }
+#endif
+      return -1;
+    }
 
   if (otv)
     {

diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index aab3df3..01baab0 100644 (file)
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -487,3 +487,8 @@
        || (__LINUX_KERNEL_VERSION >= 0x020618 && defined __s390__))
 # define __ASSUME_FALLOCATE    1
 #endif
+
+/* Support for ADJ_OFFSET_SS_READ was added in 2.6.24.  */
+#if __LINUX_KERNEL_VERSION >= 0x020618
+# define __ASSUME_ADJ_OFFSET_SS_READ   1
+#endif

diff --git a/sysdeps/unix/sysv/linux/sys/timex.h b/sysdeps/unix/sysv/linux/sys/timex.h
index 773a5ab..f7bd6e7 100644 (file)
--- a/sysdeps/unix/sysv/linux/sys/timex.h
+++ b/sysdeps/unix/sysv/linux/sys/timex.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995, 1996, 1997, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996, 1997, 1999, 2007 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -69,6 +69,7 @@ struct timex
 #define ADJ_TIMECONST          0x0020  /* pll time constant */
 #define ADJ_TICK               0x4000  /* tick value */
 #define ADJ_OFFSET_SINGLESHOT  0x8001  /* old-fashioned adjtime */
+#define ADJ_OFFSET_SS_READ     0xa001  /* read-only adjtime */
 
 /* xntp 3.4 compatibility names */
 #define MOD_OFFSET     ADJ_OFFSET