Remove access to legacy time zone support in gettimeofday etc.zack/gtod-no-timezone

gettimeofday and ftime are not quite fully implementable on systems
that only provide a primitive equivalent to clock_gettime, because
they can also report information about a system-wide time zone.  This
mechanism has been deprecated for many years because it can only be
configured on a system-wide basis, and because it only supports the
simplest kinds of daylight-savings rules, but we’ve supported it on a
best-effort basis until now.  This patch removes our support for it:

 * The type 'struct timezone' is still declared as a complete type in
   <sys/time.h>, but code that uses its fields (tz_minuteswest and
   tz_dsttime) will not compile.

 * Similarly, code that uses the 'timezone' and 'dstflag' fields of
   struct timeb will not compile anymore.  (This is a willful
   violation of the older iterations of XPG that included
   sys/timeb.h; the relevant conformance tests are XFAILed.)

 * Old binaries that pass a non-NULL 'tzp' pointer to gettimeofday
   will always receive a 'struct timezone' whose tz_minuteswest and
   tz_dsttime fields are zero (as if the system were operating on UTC).

 * Similarly, old binaries that call ftime will always receive a
   'struct timeb' whose timezone and dstflag fields are zero.

 * If the 'tzp' argument to settimeofday is not NULL, the call will fail
   and set errno to ENOSYS.  (This was already the case on the Hurd.)

 * glibc will always pass a second argument of NULL when invoking a
   kernel-provided gettimeofday.

 * On Alpha, the compat symbols gettimeofday@GLIBC_2.0 and
   settimeofday@GLIBC_2.0 (which used 32-bit time_t) now convert
   their arguments and call system primitives that use 64-bit time_t,
   instead of invoking legacy “osf” system calls.

ChangeLog:

	* time/sys/time.h (struct timezone): Remove tz_minuteswest
	and tz_dsttime fields; replace with padding to preserve the size.
	* time/sys/timeb.h (struct timeb): Remove timezone and dstflag
	fields; replace with padding to preserve the size.
	* conform/Makefile: XFAIL tests because struct timeb is no longer
	fully conformant with Unix98.

	* sysdeps/posix/gettimeofday.c
	* sysdeps/unix/sysv/linux/gettimeofday.c
	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
	* sysdeps/unix/sysv/linux/x86/gettimeofday.c
	(gettimeofday): When ‘tz’ argument is not NULL, just clear it.
	Always pass a null pointer as the second argument to a
	gettimeofday (v)syscall.

	* sysdeps/unix/bsd/ftime.c: Unconditionally clear the memory that
	was formerly the ‘timezone’ and ‘dstflag’ fields of struct timeb.

	* sysdeps/unix/syscalls.list: Remove entry for settimeofday.
	* sysdeps/unix/settimeofday.c: New file.
	(settimeofday): Fail with ENOSYS if ‘tz’ argument is not NULL.

	* sysdeps/unix/sysv/linux/alpha/syscalls.list: Remove entries for
        osf_gettimeofday, osf_settimeofday, and settimeofday.
	* sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c:
	New file.  Call the 64-bit gettimeofday, then convert to a
	32-bit struct timeval.  On overflow, saturate the struct timeval
	and fail with EOVERFLOW.
	* sysdeps/unix/sysv/linux/alpha/osf_settimeofday.c: New file.
        Convert to a 64-bit struct timeval and call 64-bit settimeofday.
        Fail with ENOSYS if ‘tz’ argument is not NULL.

	* sunrpc/auth_des.c, sunrpc/auth_unix.c
	* sysdeps/posix/time.c, sysdeps/unix/stime.c:
	Remove unnecessary casts of NULL.

	* sysdeps/unix/sysv/linux/powerpc/time.c (time_syscall):
	Use (void *)0 instead of NULL when passing a null pointer
	as an untyped argument.

	* manual/time.texi: Remove documentation of fields of
	struct timezone.  Revise text to further emphasize that
	the second argument to gettimeofday/settimeofday should
	always be a null pointer.

12 files changed, 183 insertions, 18 deletions

diff --git a/sysdeps/unix/bsd/ftime.c b/sysdeps/unix/bsd/ftime.c
index 3a1c6e9..32ce84e 100644
--- a/sysdeps/unix/bsd/ftime.c
+++ b/sysdeps/unix/bsd/ftime.c
@@ -17,14 +17,14 @@
 
 #include <sys/timeb.h>
 #include <sys/time.h>
+#include <string.h>
 
 int
 ftime (struct timeb *timebuf)
 {
   struct timeval tv;
-  struct timezone tz;
 
-  if (__gettimeofday (&tv, &tz) < 0)
+  if (__gettimeofday (&tv, 0) < 0)
     return -1;
 
   timebuf->time = tv.tv_sec;
@@ -34,7 +34,9 @@ ftime (struct timeb *timebuf)
       ++timebuf->time;
       timebuf->millitm = 0;
     }
-  timebuf->timezone = tz.tz_minuteswest;
-  timebuf->dstflag = tz.tz_dsttime;
+
+  memset (timebuf->__preserve_historic_size, 0,
+          sizeof timebuf->__preserve_historic_size);
+
   return 0;
 }
diff --git a/sysdeps/unix/settimeofday.c b/sysdeps/unix/settimeofday.c
new file mode 100644
index 0000000..741493b
--- /dev/null
+++ b/sysdeps/unix/settimeofday.c
@@ -0,0 +1,36 @@
+/* settimeofday -- Set the current time of day.  Unix version.
+   Copyright (C) 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sys/time.h>
+#include <sysdep.h>
+#include <libc-symbols.h>
+
+/* Set the current time of day and timezone information.
+   This call is restricted to the super-user.  */
+int
+__settimeofday (const struct timeval *tv, const struct timezone *tz)
+{
+  if (tz)
+    {
+      __set_errno (ENOSYS);
+      return -1;
+    }
+  return INLINE_SYSCALL_CALL (settimeofday, tv, (void *)0);
+}
+weak_alias (__settimeofday, settimeofday);
diff --git a/sysdeps/unix/stime.c b/sysdeps/unix/stime.c
index b0809be..554b3ef 100644
--- a/sysdeps/unix/stime.c
+++ b/sysdeps/unix/stime.c
@@ -35,5 +35,5 @@ stime (const time_t *when)
 
   tv.tv_sec = *when;
   tv.tv_usec = 0;
-  return __settimeofday (&tv, (struct timezone *) 0);
+  return __settimeofday (&tv, 0);
 }
diff --git a/sysdeps/unix/syscalls.list b/sysdeps/unix/syscalls.list
index 61e5360..5fedd57 100644
--- a/sysdeps/unix/syscalls.list
+++ b/sysdeps/unix/syscalls.list
@@ -76,7 +76,6 @@ setreuid	-	setreuid	i:ii	__setreuid	setreuid
 setrlimit	-	setrlimit	i:ip	__setrlimit setrlimit
 setsid		-	setsid		i:	__setsid	setsid
 setsockopt	-	setsockopt	i:iiibn	setsockopt	__setsockopt
-settimeofday	-	settimeofday	i:PP	__settimeofday	settimeofday
 setuid		-	setuid		i:i	__setuid	setuid
 shutdown	-	shutdown	i:ii	shutdown
 sigaction	-	sigaction	i:ipp	__sigaction	sigaction
diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
index 9180b50..47330e2 100644
--- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
@@ -35,7 +35,9 @@
 static int
 __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_VSYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 
 /* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
@@ -61,7 +63,9 @@ __hidden_ver1 (__gettimeofday_vsyscall, __GI___gettimeofday,
 int
 __gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_SYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 libc_hidden_def (__gettimeofday)
 
diff --git a/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c b/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c
new file mode 100644
index 0000000..8e57727
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/osf_gettimeofday.c
@@ -0,0 +1,62 @@
+/* gettimeofday -- Get the current time of day.  Linux/Alpha/tv32 version.
+   Copyright (C) 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <limits.h>
+#include <sys/time.h>
+#include <sysdep.h>
+#include <shlib-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+
+struct timeval32
+{
+    int tv_sec, tv_usec;
+};
+
+/* Get the current time of day and timezone information.  */
+int
+attribute_compat_text_section
+__gettimeofday_tv32 (struct timeval32 *tv32,
+                     struct timezone *tz)
+{
+  struct timeval tv64;
+  if (__gettimeofday (&tv64, tz))
+    return -1;
+
+  /* The tv_sec field of a 64-bit struct timeval will overflow the
+     range representable by 'int' at 2038-01-19 03:14:07 +0000.  */
+  if (tv64.tv_sec > (time_t)INT_MAX)
+    {
+      tv32.tv_sec = INT_MAX;
+      tv32.tv_usec = 0;
+      __set_errno (EOVERFLOW);
+      return -1;
+    }
+  tv32.tv_sec = (int)tv64.tv_sec;
+
+  /* The tv_usec field of a 64-bit struct timeval may be a 64-bit
+     type, but it never contains a value outside the range [0, 999999],
+     so this cast is guaranteed not to lose information.  */
+  tv32.tv_usec = (int)tv64.tv_usec;
+
+  return 0;
+}
+
+compat_symbol (libc, __gettimeofday_tv32, gettimeofday, GLIBC_2_0);
+#endif
diff --git a/sysdeps/unix/sysv/linux/alpha/osf_settimeofday.c b/sysdeps/unix/sysv/linux/alpha/osf_settimeofday.c
new file mode 100644
index 0000000..2ab2f81
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/osf_settimeofday.c
@@ -0,0 +1,51 @@
+/* settimeofday -- Set the current time of day.  Linux/Alpha/tv32 version.
+   Copyright (C) 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sys/time.h>
+#include <sysdep.h>
+#include <shlib-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+
+struct timeval32
+{
+    int tv_sec, tv_usec;
+};
+
+/* Set the current time of day and timezone information.
+   This call is restricted to the super-user.  */
+int
+attribute_compat_text_section
+__settimeofday_tv32 (const struct timeval32 *tv32,
+                     const struct timezone *tz)
+{
+  if (tz)
+    {
+      __set_errno (ENOSYS);
+      return -1;
+    }
+
+  struct timeval tv64;
+  tv64.tv_sec = tv32.tv_sec;
+  tv64.tv_usec = tv32.tv_usec;
+  return INLINE_SYSCALL_CALL (settimeofday, tv, (void *)0);
+}
+
+compat_symbol (libc, __settimeofday_tv32, settimeofday, GLIBC_2_0);
+#endif
diff --git a/sysdeps/unix/sysv/linux/alpha/syscalls.list b/sysdeps/unix/sysv/linux/alpha/syscalls.list
index 12cd021..8244f94 100644
--- a/sysdeps/unix/sysv/linux/alpha/syscalls.list
+++ b/sysdeps/unix/sysv/linux/alpha/syscalls.list
@@ -23,8 +23,6 @@ pciconfig_write	EXTRA	pciconfig_write	5	pciconfig_write
 pciconfig_iobase EXTRA	pciconfig_iobase 3	__pciconfig_iobase pciconfig_iobase
 
 # support old timeval32 entry points
-osf_gettimeofday -	osf_gettimeofday 2	__gettimeofday_tv32  __gettimeofday@GLIBC_2.0 gettimeofday@GLIBC_2.0
-osf_settimeofday -	osf_settimeofday 2	__settimeofday_tv32  settimeofday@GLIBC_2.0
 osf_getitimer	-	osf_getitimer	2	__getitimer_tv32  getitimer@GLIBC_2.0
 osf_setitimer	-	osf_setitimer	3	__setitimer_tv32  setitimer@GLIBC_2.0
 osf_utimes	-	osf_utimes	2	__utimes_tv32  utimes@GLIBC_2.0
@@ -33,7 +31,6 @@ osf_wait4	-	osf_wait4	4	__wait4_tv32  wait4@GLIBC_2.0
 
 # support new timeval64 entry points
 gettimeofday	-	gettimeofday	2	__GI___gettimeofday gettimeofday@@GLIBC_2.1 __gettimeofday@@GLIBC_2.1
-settimeofday	-	settimeofday	2	__settimeofday settimeofday@@GLIBC_2.1
 getitimer	-	getitimer	2	__getitimer getitimer@@GLIBC_2.1
 setitimer	-	setitimer	3	__setitimer setitimer@@GLIBC_2.1
 utimes		-	utimes		2	__utimes utimes@@GLIBC_2.1
diff --git a/sysdeps/unix/sysv/linux/gettimeofday.c b/sysdeps/unix/sysv/linux/gettimeofday.c
index a74f038..3509ca9 100644
--- a/sysdeps/unix/sysv/linux/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/gettimeofday.c
@@ -18,6 +18,7 @@
 
 #include <errno.h>
 #include <sys/time.h>
+#include <string.h>
 
 #undef __gettimeofday
 
@@ -32,7 +33,9 @@
 int
 __gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_VSYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 libc_hidden_def (__gettimeofday)
 weak_alias (__gettimeofday, gettimeofday)
diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
index 463b678..e798a80 100644
--- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
@@ -22,6 +22,7 @@
 #endif
 
 #include <sys/time.h>
+#include <string.h>
 
 #ifdef SHARED
 
@@ -35,7 +36,9 @@
 int
 __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_VSYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 
 /* __GI___gettimeofday is defined as hidden and for ppc32 it enables the
@@ -54,7 +57,9 @@ __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
 static int
 __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_SYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 
 # define INIT_ARCH()						\
@@ -76,7 +81,9 @@ libc_hidden_def (__gettimeofday)
 int
 __gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_SYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 libc_hidden_def (__gettimeofday)
 
diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c
index cb3e8b9..42b0d2d 100644
--- a/sysdeps/unix/sysv/linux/powerpc/time.c
+++ b/sysdeps/unix/sysv/linux/powerpc/time.c
@@ -56,7 +56,7 @@ time_syscall (time_t *t)
   struct timeval tv;
   time_t result;
 
-  if (INLINE_VSYSCALL (gettimeofday, 2, &tv, NULL) < 0)
+  if (INLINE_VSYSCALL (gettimeofday, 2, &tv, (void *)0) < 0)
     result = (time_t) -1;
   else
     result = (time_t) tv.tv_sec;
diff --git a/sysdeps/unix/sysv/linux/x86/gettimeofday.c b/sysdeps/unix/sysv/linux/x86/gettimeofday.c
index 8886ccd..58a8763 100644
--- a/sysdeps/unix/sysv/linux/x86/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/x86/gettimeofday.c
@@ -26,7 +26,9 @@
 static int
 __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_SYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 
 # ifndef __gettimeofday_type
@@ -52,7 +54,9 @@ libc_hidden_def (__gettimeofday)
 int
 __gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-  return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
+  if (tz)
+    memset (tz, 0, sizeof (struct timezone));
+  return INLINE_SYSCALL (gettimeofday, 2, tv, (void *)0);
 }
 libc_hidden_def (__gettimeofday)