Change most internal uses of time to __clock_gettime.

As for gettimeofday, time will be implemented based on clock_gettime
on all platforms and internal code should use clock_gettime
directly.  In addition to removing a layer of indirection, this will
allow us to remove the PLT-bypass gunk for gettimeofday.

The changed code always assumes __clock_gettime (CLOCK_REALTIME)
or __clock_gettime (CLOCK_REALTIME_COARSE) (for Linux case) cannot
fail, using the same rationale for gettimeofday change.  And internal
helper was added (time_now).

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, and powerpc-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>

include/time.h

@@ -7,12 +7,12 @@
 # include <stdbool.h>
 # include <time/mktime-internal.h>
 # include <endian.h>
+# include <time-clockid.h>
 
 extern __typeof (strftime_l) __strftime_l;
 libc_hidden_proto (__strftime_l)
 extern __typeof (strptime_l) __strptime_l;
 
-libc_hidden_proto (time)
 libc_hidden_proto (asctime)
 libc_hidden_proto (mktime)
 libc_hidden_proto (timelocal)
@@ -252,5 +252,15 @@ valid_nanoseconds (__syscall_slong_t ns)
 {
   return __glibc_likely (0 <= ns && ns < 1000000000);
 }
+
+/* Helper function to get time in seconds, similar to time.  */
+static inline time_t
+time_now (void)
+{
+  struct timespec ts;
+  __clock_gettime (TIME_CLOCK_GETTIME_CLOCKID, &ts);
+  return ts.tv_sec;
+}
 #endif
+
 #endif

misc/syslog.c

@@ -205,7 +205,7 @@ __vsyslog_internal(int pri, const char *fmt, va_list ap,
 	  {
 	    __fsetlocking (f, FSETLOCKING_BYCALLER);
 	    fprintf (f, "<%d>", pri);
-	    now = time (NULL);
+	    now = time_now ();
 	    f->_IO_write_ptr += __strftime_l (f->_IO_write_ptr,
 					      f->_IO_write_end
 					      - f->_IO_write_ptr,

nscd/nscd_gethst_r.c

@@ -113,7 +113,7 @@ __nscd_get_nl_timestamp (void)
   if (map == NULL
       || (map != NO_MAPPING
 	  && map->head->nscd_certainly_running == 0
-	  && map->head->timestamp + MAPPING_TIMEOUT < time (NULL)))
+	  && map->head->timestamp + MAPPING_TIMEOUT < time_now ()))
     map = __nscd_get_mapping (GETFDHST, "hosts", &__hst_map_handle.mapped);
 
   if (map == NO_MAPPING)

nscd/nscd_helper.c

@@ -348,7 +348,7 @@ __nscd_get_mapping (request_type type, const char *key,
 	     thread got stuck.  */
 	  || __builtin_expect (! head->nscd_certainly_running
 			       && (head->timestamp + MAPPING_TIMEOUT
-				   < time (NULL)), 0))
+				   < time_now ()), 0))
 	{
 	out_unmap:
 	  __munmap (mapping, mapsize);
@@ -414,7 +414,7 @@ __nscd_get_map_ref (request_type type, const char *name,
       /* If not mapped or timestamp not updated, request new map.  */
       if (cur == NULL
 	  || (cur->head->nscd_certainly_running == 0
-	      && cur->head->timestamp + MAPPING_TIMEOUT < time (NULL))
+	      && cur->head->timestamp + MAPPING_TIMEOUT < time_now ())
 	  || cur->head->data_size > cur->datasize)
 	cur = __nscd_get_mapping (type, name,
 				  (struct mapped_database **) &mapptr->mapped);

string/strfry.c

@@ -17,7 +17,7 @@
 
 #include <string.h>
 #include <stdlib.h>
-#include <time.h>
+#include <random-bits.h>
 #include <unistd.h>
 
 char *
@@ -30,7 +30,7 @@ strfry (char *string)
     {
       static char state[32];
       rdata.state = NULL;
-      __initstate_r (time (NULL) ^ getpid (),
+      __initstate_r (random_bits (),
 		     state, sizeof (state), &rdata);
       init = 1;
     }

sysdeps/unix/sysv/linux/check_native.c

@@ -69,7 +69,7 @@ __check_native (uint32_t a1_index, int *a1_native,
   req.nlh.nlmsg_type = RTM_GETLINK;
   req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
   req.nlh.nlmsg_pid = 0;
-  req.nlh.nlmsg_seq = time (NULL);
+  req.nlh.nlmsg_seq = time_now ();
   req.g.rtgen_family = AF_UNSPEC;
 
   assert (sizeof (req) - offsetof (struct req, pad) == 3);

sysdeps/unix/sysv/linux/check_pf.c

@@ -126,7 +126,7 @@ make_request (int fd, pid_t pid)
   req.nlh.nlmsg_type = RTM_GETADDR;
   req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
   req.nlh.nlmsg_pid = 0;
-  req.nlh.nlmsg_seq = time (NULL);
+  req.nlh.nlmsg_seq = time_now ();
   req.g.rtgen_family = AF_UNSPEC;
 
   assert (sizeof (req) - offsetof (struct req, pad) == 3);

sysdeps/unix/sysv/linux/getsysstats.c

@@ -128,7 +128,7 @@ __get_nprocs (void)
   static int cached_result = -1;
   static time_t timestamp;
 
-  time_t now = time (NULL);
+  time_t now = time_now ();
   time_t prev = timestamp;
   atomic_read_barrier ();
   if (now == prev && cached_result > -1)

sysdeps/unix/sysv/linux/i386/time.c

@@ -1,34 +0,0 @@
-/* time -- Get number of seconds since Epoch.  Linux/i386 version.
-   Copyright (C) 2015-2019 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
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#ifdef SHARED
-# define time __redirect_time
-#endif
-
-#include <time.h>
-
-#ifdef SHARED
-# undef time
-# define time_type __redirect_time
-
-# undef libc_hidden_def
-# define libc_hidden_def(name)  \
-  __hidden_ver1 (__time_syscall, __GI_time, __time_syscall);
-#endif
-
-#include <sysdeps/unix/sysv/linux/x86/time.c>

sysdeps/unix/sysv/linux/ifaddrs.c

@@ -102,7 +102,7 @@ __netlink_sendreq (struct netlink_handle *h, int type)
   struct sockaddr_nl nladdr;
 
   if (h->seq == 0)
-    h->seq = time (NULL);
+    h->seq = time_now ();
 
   req.nlh.nlmsg_len = sizeof (req);
   req.nlh.nlmsg_type = type;

sysdeps/unix/sysv/linux/powerpc/time.c

@@ -16,68 +16,37 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#ifdef SHARED
-# ifndef __powerpc64__
-#  define time __redirect_time
-# else
-#  define __redirect_time time
-# endif
-
 #include <time.h>
 #include <sysdep.h>
-# include <dl-vdso.h>
-# include <libc-vdso.h>
-# include <dl-machine.h>
 
-# ifndef __powerpc64__
-#  undef time
+#ifdef HAVE_TIME_VSYSCALL
+# define HAVE_VSYSCALL
+#endif
+#include <sysdep-vdso.h>
 
-time_t
-__time_vsyscall (time_t *t)
+static time_t
+time_vsyscall (time_t *t)
 {
   return INLINE_VSYSCALL (time, 1, t);
 }
 
-/* __GI_time is defined as hidden and for ppc32 it enables the
-   compiler make a local call (symbol@local) for internal GLIBC usage. It
-   means the PLT won't be used and the ifunc resolver will be called directly.
-   For ppc64 a call to a function in another translation unit might use a
-   different toc pointer thus disallowing direct branchess and making internal
-   ifuncs calls safe.  */
-#  undef libc_hidden_def
-#  define libc_hidden_def(name)					\
-  __hidden_ver1 (__time_vsyscall, __GI_time, __time_vsyscall);
-
-# endif /* !__powerpc64__  */
-
-static time_t
-time_syscall (time_t *t)
-{
-  struct timeval tv;
-  time_t result;
-
-  if (INLINE_VSYSCALL (gettimeofday, 2, &tv, NULL) < 0)
-    result = (time_t) -1;
-  else
-    result = (time_t) tv.tv_sec;
-
-  if (t != NULL)
-    *t = result;
-  return result;
-}
+#ifdef SHARED
+# include <dl-vdso.h>
+# include <libc-vdso.h>
 
 # define INIT_ARCH() \
   void *vdso_time = get_vdso_symbol (HAVE_TIME_VSYSCALL);
 
 /* If the vDSO is not available we fall back to the syscall.  */
-libc_ifunc_hidden (__redirect_time, time,
+libc_ifunc (time,
 	    vdso_time
 	    ? VDSO_IFUNC_RET (vdso_time)
-		   : (void *) time_syscall);
-libc_hidden_def (time)
+	    : (void *) time_vsyscall);
 
 #else
-
-#include <time/time.c>
-
+time_t
+time (time_t *t)
+{
+  return time_vsyscall (t);
+}
 #endif /* !SHARED */

sysdeps/unix/sysv/linux/x86/time.c

@@ -17,43 +17,31 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include <time.h>
+#include <sysdep.h>
 
-#ifdef SHARED
-
-#include <dl-vdso.h>
-#include <errno.h>
+#ifdef HAVE_TIME_VSYSCALL
+# define HAVE_VSYSCALL
+#endif
 #include <sysdep-vdso.h>
 
 static time_t
-__time_syscall (time_t *t)
+time_vsyscall (time_t *t)
 {
-  INTERNAL_SYSCALL_DECL (err);
-  return INTERNAL_SYSCALL (time, err, 1, t);
+  return INLINE_VSYSCALL (time, 1, t);
 }
 
-# ifndef time_type
-/* The i386 time.c includes this file with a defined time_type macro.
-   For x86_64 we have to define it to time as the internal symbol is the
-   ifunc'ed one.  */
-#  define time_type time
-# endif
+#ifdef SHARED
+# include <dl-vdso.h>
+# include <libc-vdso.h>
 
 #undef INIT_ARCH
 #define INIT_ARCH()
 /* If the vDSO is not available we fall back on the syscall.  */
-libc_ifunc_hidden (time_type, time,
-		   (get_vdso_symbol ("__vdso_time") ?: __time_syscall))
-libc_hidden_def (time)
-
+libc_ifunc (time, (get_vdso_symbol ("__vdso_time") ?: time_vsyscall))
 #else
-
-# include <sysdep.h>
-
 time_t
 time (time_t *t)
 {
-  INTERNAL_SYSCALL_DECL (err);
-  return INTERNAL_SYSCALL (time, err, 1, t);
+  return time_vsyscall (t);
 }
-
 #endif

time/getdate.c

@@ -219,7 +219,7 @@ __getdate_r (const char *string, struct tm *tp)
     return 7;
 
   /* Get current time.  */
-  timer = time (NULL);
+  timer = time_now ();
   __localtime_r (&timer, &tm);
 
   /* If only the weekday is given, today is assumed if the given day

time/time.c

@@ -29,4 +29,3 @@ time (time_t *timer)
     *timer = ts.tv_sec;
   return ts.tv_sec;
 }
-libc_hidden_def (time)