login: Check default sizes of structs utmp, utmpx, lastlog

The default <utmp-size.h> is for ports with a 64-bit time_t.
Ports with a 32-bit time_t or with __WORDSIZE_TIME64_COMPAT32=1
need to override it.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

login/Makefile

@@ -44,7 +44,7 @@ subdir-dirs = programs
 vpath %.c programs
 
 tests := tst-utmp tst-utmpx tst-grantpt tst-ptsname tst-getlogin tst-updwtmpx \
-  tst-pututxline-lockfail tst-pututxline-cache
+  tst-pututxline-lockfail tst-pututxline-cache tst-utmp-size
 
 # Empty compatibility library for old binaries.
 extra-libs      := libutil

login/tst-utmp-size.c

@@ -0,0 +1,33 @@
+/* Check expected sizes of struct utmp, struct utmpx, struct lastlog.
+   Copyright (C) 2024 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 <utmp.h>
+#include <utmpx.h>
+#include <utmp-size.h>
+
+static int
+do_test (void)
+{
+  _Static_assert (sizeof (struct utmp) == UTMP_SIZE, "struct utmp size");
+  _Static_assert (sizeof (struct utmpx) == UTMP_SIZE, "struct utmpx size");
+  _Static_assert (sizeof (struct lastlog) == LASTLOG_SIZE,
+                  "struct lastlog size");
+  return 0;
+}
+
+#include <support/test-driver.c>

sysdeps/arc/utmp-size.h

@@ -0,0 +1,3 @@
+/* arc has less padding than other architectures with 64-bit time_t.  */
+#define UTMP_SIZE 392
+#define LASTLOG_SIZE 296

sysdeps/arm/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/csky/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/generic/utmp-size.h

@@ -0,0 +1,23 @@
+/* Expected sizes of utmp-related structures stored in files.  64-bit version.
+   Copyright (C) 2024 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/>.  */
+
+/* Expected size, in bytes, of struct utmp and struct utmpx.  */
+#define UTMP_SIZE 400
+
+/* Expected size, in bytes, of struct lastlog.  */
+#define LASTLOG_SIZE 296

sysdeps/hppa/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/m68k/utmp-size.h

@@ -0,0 +1,3 @@
+/* m68k has 2-byte alignment.  */
+#define UTMP_SIZE 382
+#define LASTLOG_SIZE 292

sysdeps/microblaze/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/mips/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/nios2/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/or1k/utmp-size.h

@@ -0,0 +1,3 @@
+/* or1k has less padding than other architectures with 64-bit time_t.  */
+#define UTMP_SIZE 392
+#define LASTLOG_SIZE 296

sysdeps/powerpc/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/riscv/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/sh/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/sparc/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292

sysdeps/x86/utmp-size.h

@@ -0,0 +1,2 @@
+#define UTMP_SIZE 384
+#define LASTLOG_SIZE 292