[glibc/azanella/y2038] login: Move gnu utmpx to default implementation

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8569f443b5bdf0d6c46154e8106c3df6ae0d196a

commit 8569f443b5bdf0d6c46154e8106c3df6ae0d196a
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue Jul 28 12:14:27 2020 -0300

    login: Move gnu utmpx to default implementation
    
    It removes one indirection where generic implementation assumes that
    utmp and utmpx might differ and allows the optimize the symbol alias
    where getutmp is the same as getumpx.
    
    Checked with make check run-built-tests=no on all afftected ABIs.

Diff:
---
 {sysdeps/gnu/bits => bits/types}/struct_utmpx.h |  0
 {sysdeps/gnu/bits => bits}/utmpx.h              |  2 +-
 include/utmpx.h                                 |  1 +
 login/Makefile                                  |  2 +-
 login/getutmp.c                                 | 34 ++++++++++++++++++++++--
 login/getutmpx.c                                | 35 +------------------------
 login/updwtmp.c                                 | 11 +++++++-
 {sysdeps/gnu => login}/utmpx.h                  |  0
 sysdeps/gnu/getutmp.c                           | 34 ------------------------
 sysdeps/gnu/getutmpx.c                          |  1 -
 sysdeps/gnu/updwtmp.c                           | 31 ----------------------
 sysdeps/unix/sysv/linux/s390/s390-32/getutmp.c  | 21 +++++----------
 sysdeps/unix/sysv/linux/s390/s390-32/updwtmp.c  |  2 +-
 13 files changed, 54 insertions(+), 120 deletions(-)

diff --git a/sysdeps/gnu/bits/struct_utmpx.h b/bits/types/struct_utmpx.h
similarity index 100%
rename from sysdeps/gnu/bits/struct_utmpx.h
rename to bits/types/struct_utmpx.h
diff --git a/sysdeps/gnu/bits/utmpx.h b/bits/utmpx.h
similarity index 98%
rename from sysdeps/gnu/bits/utmpx.h
rename to bits/utmpx.h
index 26ec95603f..b2947b1c13 100644
--- a/sysdeps/gnu/bits/utmpx.h
+++ b/bits/utmpx.h
@@ -51,7 +51,7 @@ struct __exit_status
   };
 
 
-#include <bits/struct_utmpx.h>
+#include <bits/types/struct_utmpx.h>
 
 
 /* Values for the `ut_type' field of a `struct utmpx'.  */
diff --git a/include/utmpx.h b/include/utmpx.h
new file mode 100644
index 0000000000..cfe9b7c054
--- /dev/null
+++ b/include/utmpx.h
@@ -0,0 +1 @@
+#include <login/utmpx.h>
diff --git a/login/Makefile b/login/Makefile
index f7059ac660..5e2cb1da06 100644
--- a/login/Makefile
+++ b/login/Makefile
@@ -26,7 +26,7 @@ include ../Makeconfig
 headers	:= utmp.h bits/utmp.h lastlog.h pty.h \
 	   bits/types/struct_lastlog.h \
 	   bits/types/struct_utmp.h \
-	   bits/struct_utmpx.h
+	   bits/types/struct_utmpx.h
 
 routines := getlogin getlogin_r setlogin getlogin_r_chk \
 	    getutent getutent_r getutid getutline getutid_r getutline_r \
diff --git a/login/getutmp.c b/login/getutmp.c
index 0401e041dd..60aafb5067 100644
--- a/login/getutmp.c
+++ b/login/getutmp.c
@@ -17,17 +17,47 @@
 
 #include <string.h>
 #include <utmp.h>
+#include <stddef.h>
+#define getutmpx __redirect_getutmpx
 #include <utmpx.h>
+#undef getutmpx
+
+#define CHECK_SIZE_AND_OFFSET(field) \
+  _Static_assert (sizeof ((struct utmp){0}.field)		\
+		  == sizeof ((struct utmpx){0}.field),		\
+		  "sizeof ((struct utmp){0}." #field " != "	\
+		  "sizeof ((struct utmpx){0}" #field);	\
+  _Static_assert (offsetof (struct utmp, field)			\
+		  == offsetof (struct utmpx, field),		\
+		  "offsetof (struct utmp, " #field ") != "	\
+		  "offsetof (struct utmpx, " #field ")");
+
+/* This ensure the getutmp to getutmpx alias is valid.  */
+_Static_assert (sizeof (struct utmp) == sizeof (struct utmpx),
+		"sizeof (struct utmp) != sizeof (struct utmpx)");
+CHECK_SIZE_AND_OFFSET (ut_type)
+CHECK_SIZE_AND_OFFSET (ut_pid)
+CHECK_SIZE_AND_OFFSET (ut_line)
+CHECK_SIZE_AND_OFFSET (ut_user)
+CHECK_SIZE_AND_OFFSET (ut_id)
+CHECK_SIZE_AND_OFFSET (ut_host)
+CHECK_SIZE_AND_OFFSET (ut_tv)
+
 
 /* Copy the information in UTMPX to UTMP. */
 void
-getutmp (const struct utmpx *utmpx, struct utmp *utmp)
+__getutmp (const struct utmpx *utmpx, struct utmp *utmp)
 {
+  memset (utmp, 0, sizeof (struct utmpx));
   utmp->ut_type = utmpx->ut_type;
   utmp->ut_pid = utmpx->ut_pid;
   memcpy (utmp->ut_line, utmpx->ut_line, sizeof (utmp->ut_line));
   memcpy (utmp->ut_user, utmpx->ut_user, sizeof (utmp->ut_user));
   memcpy (utmp->ut_id, utmpx->ut_id, sizeof (utmp->ut_id));
   memcpy (utmp->ut_host, utmpx->ut_host, sizeof (utmp->ut_host));
-  utmp->ut_tv = utmpx->ut_tv;
+  utmp->ut_tv.tv_sec = utmpx->ut_tv.tv_sec;
+  utmp->ut_tv.tv_usec = utmpx->ut_tv.tv_usec;
 }
+
+weak_alias (__getutmp, getutmp)
+strong_alias (__getutmp, getutmpx)
diff --git a/login/getutmpx.c b/login/getutmpx.c
index 228726a05a..839eb6826e 100644
--- a/login/getutmpx.c
+++ b/login/getutmpx.c
@@ -1,34 +1 @@
-/* Copyright (C) 1999-2021 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/>.  */
-
-#include <string.h>
-#include <utmp.h>
-#include <utmpx.h>
-
-/* Copy the information in UTMP to UTMPX. */
-void
-getutmpx (const struct utmp *utmp, struct utmpx *utmpx)
-{
-  memset (utmpx, 0, sizeof (struct utmpx));
-  utmpx->ut_type = utmp->ut_type;
-  utmpx->ut_pid = utmp->ut_pid;
-  memcpy (utmpx->ut_line, utmp->ut_line, sizeof (utmp->ut_line));
-  memcpy (utmpx->ut_user, utmp->ut_user, sizeof (utmp->ut_user));
-  memcpy (utmpx->ut_id, utmp->ut_id, sizeof (utmp->ut_id));
-  memcpy (utmpx->ut_host, utmp->ut_host, sizeof (utmp->ut_host));
-  utmpx->ut_tv = utmp->ut_tv;
-}
+/* Implemented by getutmp.c. */
diff --git a/login/updwtmp.c b/login/updwtmp.c
index 0558198464..ae67cfc10a 100644
--- a/login/updwtmp.c
+++ b/login/updwtmp.c
@@ -17,11 +17,20 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include <utmp.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "utmp-private.h"
 
 #ifndef TRANSFORM_UTMP_FILE_NAME
-# define TRANSFORM_UTMP_FILE_NAME(file_name) (file_name)
+# define TRANSFORM_UTMP_FILE_NAME(file_name)	\
+  ((strcmp (file_name, _PATH_UTMP "x") == 0	\
+    && __access (_PATH_UTMP "x", F_OK) != 0)	\
+   ? _PATH_UTMP					\
+   : ((strcmp (file_name, _PATH_WTMP "x") == 0	\
+       && __access (_PATH_WTMP "x", F_OK) != 0)	\
+      ? _PATH_WTMP				\
+      : file_name))
 #endif
 
 void
diff --git a/sysdeps/gnu/utmpx.h b/login/utmpx.h
similarity index 100%
rename from sysdeps/gnu/utmpx.h
rename to login/utmpx.h
diff --git a/sysdeps/gnu/getutmp.c b/sysdeps/gnu/getutmp.c
deleted file mode 100644
index 4ce9d65ce0..0000000000
--- a/sysdeps/gnu/getutmp.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/* Copyright (C) 1999-2021 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/>.  */
-
-#include <assert.h>
-#include <string.h>
-#include <utmp.h>
-#ifndef _UTMPX_H
-/* This is an ugly hack but we must not see the getutmpx declaration.  */
-# define getutmpx XXXgetutmpx
-# include <utmpx.h>
-# undef getutmpx
-#endif
-
-void
-getutmp (const struct utmpx *utmpx, struct utmp *utmp)
-{
-  assert (sizeof (struct utmp) == sizeof (struct utmpx));
-  memcpy (utmp, utmpx, sizeof (struct utmp));
-}
-strong_alias (getutmp, getutmpx)
diff --git a/sysdeps/gnu/getutmpx.c b/sysdeps/gnu/getutmpx.c
deleted file mode 100644
index f393734a63..0000000000
--- a/sysdeps/gnu/getutmpx.c
+++ /dev/null
@@ -1 +0,0 @@
-/* We don't need a separate version.  it is the same as getutmp().  */
diff --git a/sysdeps/gnu/updwtmp.c b/sysdeps/gnu/updwtmp.c
deleted file mode 100644
index a1cb93d75d..0000000000
--- a/sysdeps/gnu/updwtmp.c
+++ /dev/null
@@ -1,31 +0,0 @@
-/* Copyright (C) 1998-2021 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1998.
-
-   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/>.  */
-
-#include <string.h>
-#include <unistd.h>
-
-#define TRANSFORM_UTMP_FILE_NAME(file_name)	\
-  ((strcmp (file_name, _PATH_UTMP "x") == 0	\
-    && __access (_PATH_UTMP "x", F_OK) != 0)	\
-   ? _PATH_UTMP					\
-   : ((strcmp (file_name, _PATH_WTMP "x") == 0	\
-       && __access (_PATH_WTMP "x", F_OK) != 0)	\
-      ? _PATH_WTMP				\
-      : file_name))
-
-#include <login/updwtmp.c>
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/getutmp.c b/sysdeps/unix/sysv/linux/s390/s390-32/getutmp.c
index 5820701f21..6ffea2a553 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/getutmp.c
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/getutmp.c
@@ -16,22 +16,15 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <string.h>
-#include <utmp.h>
-/* This is an ugly hack but we must not see the getutmpx declaration.  */
-#define getutmpx XXXgetutmpx
-#include <utmpx.h>
-#undef getutmpx
+#undef weak_alias
+#define weak_alias(a, b)
+#undef strong_alias
+#define strong_alias(a, b)
 
-#include "utmp-compat.h"
+#include <login/getutmp.c>
 
-#undef weak_alias
-#define weak_alias(n,a)
-#define getutmp __getutmp
-#define getutmpx __getutmpx
-#include "sysdeps/gnu/getutmp.c"
-#undef getutmp
-#undef getutmpx
+#include "utmp-compat.h"
 
 default_symbol_version (__getutmp, getutmp, UTMP_COMPAT_BASE);
+_strong_alias (__getutmp, __getutmpx)
 default_symbol_version (__getutmpx, getutmpx, UTMP_COMPAT_BASE);
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/updwtmp.c b/sysdeps/unix/sysv/linux/s390/s390-32/updwtmp.c
index d4aa0ce2ac..7ef8e85c00 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/updwtmp.c
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/updwtmp.c
@@ -25,7 +25,7 @@
 # undef weak_alias
 # define weak_alias(n,a)
 #endif
-#include "sysdeps/gnu/updwtmp.c"
+#include <login/updwtmp.c>
 
 #if defined SHARED
 default_symbol_version (__updwtmp, updwtmp, UTMP_COMPAT_BASE);