[PATCH v2 4/6] linux: Use long time_t __getitimer/__setitimer

[Alistair Francis <alistair dot francis at wdc dot com>]

The Linux kernel expects itimerval to use a 32-bit time_t, even on archs
with a 64-bit time_t (like RV32). To address this let's convert
itimerval to/from 32-bit and 64-bit to ensure the kernel always gets
a 32-bit time_t.

While we are converting these functions let's also convert them to be
the y2038 safe versions. This means there is a *64 function that is
called by a backwards compatible wrapper.
---
 include/time.h                        | 12 ++++
 sysdeps/unix/sysv/linux/getitimer.c   | 54 ++++++++++++++++
 sysdeps/unix/sysv/linux/setitimer.c   | 89 +++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/tv32-compat.h | 35 +++++++++++
 4 files changed, 190 insertions(+)
 create mode 100644 sysdeps/unix/sysv/linux/getitimer.c
 create mode 100644 sysdeps/unix/sysv/linux/setitimer.c
 create mode 100644 sysdeps/unix/sysv/linux/tv32-compat.h

diff --git a/include/time.h b/include/time.h
index 684dabba9c..52b1aba70e 100644
--- a/include/time.h
+++ b/include/time.h
@@ -6,6 +6,7 @@
 # include <bits/types/locale_t.h>
 # include <stdbool.h>
 # include <time/mktime-internal.h>
+# include <sys/time.h>
 # include <endian.h>
 # include <time-clockid.h>
 # include <sys/time.h>
@@ -119,6 +120,17 @@ struct __itimerval64
 };
 #endif
 
+#if __TIMESIZE == 64
+# define __getitimer64 __getitimer
+# define __setitimer64 __setitimer
+#else
+extern int __getitimer64 (enum __itimer_which __which,
+                          struct __itimerval64 *__value);
+extern int __setitimer64 (enum __itimer_which __which,
+                          const struct __itimerval64 *__restrict __new,
+                          struct __itimerval64 *__restrict __old);
+#endif
+
 #if __TIMESIZE == 64
 # define __ctime64 ctime
 #else
diff --git a/sysdeps/unix/sysv/linux/getitimer.c b/sysdeps/unix/sysv/linux/getitimer.c
new file mode 100644
index 0000000000..28a3e31126
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/getitimer.c
@@ -0,0 +1,54 @@
+/* getitimer -- Get the state of an interval timer.  Linux/tv32 version.
+   Copyright (C) 2020 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 <time.h>
+#include <sys/time.h>
+#include <sysdep.h>
+#include <tv32-compat.h>
+
+int
+__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
+{
+  struct __itimerval32 curr_value_32;
+  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
+    return -1;
+
+  /* Write all fields of 'curr_value' regardless of overflow.  */
+  curr_value->it_interval
+    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
+  curr_value->it_value
+    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
+  return 0;
+}
+
+
+#if __TIMESIZE != 64
+int
+__getitimer (__itimer_which_t which, struct itimerval *curr_value)
+{
+  struct __itimerval64 val64;
+
+  val64.it_interval
+    = valid_timeval_to_timeval64 (curr_value->it_interval);
+  val64.it_value
+    = valid_timeval_to_timeval64 (curr_value->it_value);
+
+  return __getitimer64 (which, &val64);
+}
+#endif
+weak_alias (__getitimer, getitimer)
diff --git a/sysdeps/unix/sysv/linux/setitimer.c b/sysdeps/unix/sysv/linux/setitimer.c
new file mode 100644
index 0000000000..99b40b3db2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/setitimer.c
@@ -0,0 +1,89 @@
+/* setitimer -- Set the state of an interval timer.  Linux/tv32 version.
+   Copyright (C) 2020 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 <time.h>
+#include <sys/time.h>
+#include <sysdep.h>
+#include <tv32-compat.h>
+
+int
+__setitimer64 (__itimer_which_t which,
+               const struct __itimerval64 *restrict new_value,
+               struct __itimerval64 *restrict old_value)
+{
+  struct __itimerval32 new_value_32;
+
+  if (! in_time_t_range (new_value->it_interval.tv_sec))
+  {
+    __set_errno (EOVERFLOW);
+    return -1;
+  }
+  new_value_32.it_interval
+    = valid_timeval64_to_timeval32 (new_value->it_interval);
+
+  if (! in_time_t_range (new_value->it_value.tv_sec))
+  {
+    __set_errno (EOVERFLOW);
+    return -1;
+  }
+  new_value_32.it_value
+    = valid_timeval64_to_timeval32 (new_value->it_value);
+
+  if (old_value == NULL)
+    return INLINE_SYSCALL_CALL (setitimer, which, &new_value_32, NULL);
+
+  struct __itimerval32 old_value_32;
+  if (INLINE_SYSCALL_CALL (setitimer, which, &new_value_32, &old_value_32) == -1)
+    return -1;
+
+  /* Write all fields of 'old_value' regardless of overflow.  */
+  old_value->it_interval
+     = valid_timeval32_to_timeval64 (old_value_32.it_interval);
+  old_value->it_value
+     = valid_timeval32_to_timeval64 (old_value_32.it_value);
+  return 0;
+}
+
+#if __TIMESIZE != 64
+int
+__setitimer (__itimer_which_t which,
+             const struct itimerval *restrict new_value,
+             struct itimerval *restrict old_value)
+{
+  int ret;
+  struct __itimerval64 new64, old64;
+
+  new64.it_interval
+    = valid_timeval_to_timeval64 (new_value->it_interval);
+  new64.it_value
+    = valid_timeval_to_timeval64 (new_value->it_value);
+
+  ret = __setitimer64 (which, &new64, &old64);
+
+  if (ret != 0)
+    return ret;
+
+  old_value->it_interval
+    = valid_timeval64_to_timeval (old64.it_interval);
+  old_value->it_value
+    = valid_timeval64_to_timeval (old64.it_value);
+
+  return ret;
+}
+#endif
+weak_alias (__setitimer, setitimer)
diff --git a/sysdeps/unix/sysv/linux/tv32-compat.h b/sysdeps/unix/sysv/linux/tv32-compat.h
new file mode 100644
index 0000000000..4eb6f216ea
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tv32-compat.h
@@ -0,0 +1,35 @@
+/* Compatibility definitions for `struct timeval' with 32-bit time_t.
+   Copyright (C) 2020 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/>.  */
+
+#ifndef _TV32_COMPAT_H
+#define _TV32_COMPAT_H 1
+
+#include <features.h>
+
+#include <bits/types.h>
+#include <bits/types/time_t.h>
+#include <bits/types/struct_timeval.h>
+
+/* Structures containing 'struct timeval' with 32-bit time_t.  */
+struct __itimerval32
+{
+  struct __timeval32 it_interval;
+  struct __timeval32 it_value;
+};
+
+#endif /* tv32-compat.h */
-- 
2.25.0