linux: Use long time_t for wait4/getrusage

The Linux kernel expects rusage to use a 32-bit time_t, even on archs
with a 64-bit time_t (like RV32). To address this let's convert
rusage 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.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

include/sys/resource.h

@@ -134,5 +134,16 @@ extern int __getrusage (enum __rusage_who __who, struct rusage *__usage)
 extern int __setrlimit (enum __rlimit_resource __resource,
 			const struct rlimit *__rlimits);
 libc_hidden_proto (__setrlimit);
+
+#if __TIMESIZE == 64
+# define __getrusage64 __getrusage
+# define __wait4_time64 __wait4
+#else
+extern int __getrusage64 (enum __rusage_who who, struct __rusage64 *usage);
+libc_hidden_proto (__getrusage64)
+extern pid_t __wait4_time64 (pid_t pid, int *stat_loc, int options,
+                             struct __rusage64 *usage);
+libc_hidden_proto (__wait4_time64)
+#endif
 #endif
 #endif

sysdeps/unix/syscalls.list

@@ -29,7 +29,6 @@ getpeername	-	getpeername	i:ibN	__getpeername	getpeername
 getpid		-	getpid		Ei:	__getpid	getpid
 getpriority	-	getpriority	i:ii	__getpriority	getpriority
 getrlimit	-	getrlimit	i:ip	__getrlimit	getrlimit
-getrusage	-	getrusage	i:ip	__getrusage	getrusage
 getsockname	-	getsockname	i:ibN	__getsockname	getsockname
 getsockopt	-	getsockopt	i:iiiBN	getsockopt
 getuid		-	getuid		Ei:	__getuid	getuid

sysdeps/unix/sysv/linux/getrusage.c

@@ -0,0 +1,58 @@
+/* getrusage -- get the rusage struct.  Linux 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 <sys/time.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sysdep.h>
+#include <tv32-compat.h>
+
+int
+__getrusage64 (enum __rusage_who who, struct __rusage64 *usage)
+{
+#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
+  return INLINE_SYSCALL_CALL (getrusage, who, usage);
+#else
+  struct __rusage32 usage32;
+  if (INLINE_SYSCALL_CALL (getrusage, who, &usage32) == -1)
+    return -1;
+
+  rusage32_to_rusage64 (&usage32, usage);
+  return 0;
+#endif
+}
+
+#if __TIMESIZE != 64
+libc_hidden_def (__getrusage64)
+int
+__getrusage (enum __rusage_who who, struct rusage *usage)
+{
+  int ret ;
+  struct __rusage64 usage64;
+
+  ret = __getrusage64 (who, &usage64);
+
+  if (ret != 0)
+    return ret;
+
+  rusage64_to_rusage (&usage64, usage);
+
+  return ret;
+}
+#endif
+weak_alias (__getrusage, getrusage)

sysdeps/unix/sysv/linux/tv32-compat.h

@@ -20,6 +20,7 @@
 #define _TV32_COMPAT_H 1
 
 #include <bits/types/time_t.h>
+#include <sys/resource.h>
 
 /* Structures containing 'struct timeval' with 32-bit time_t.  */
 struct __itimerval32
@@ -28,4 +29,50 @@ struct __itimerval32
   struct __timeval32 it_value;
 };
 
+struct __rusage32
+{
+  struct __timeval32 ru_utime;	/* user time used */
+  struct __timeval32 ru_stime;	/* system time used */
+  long ru_maxrss;		/* maximum resident set size */
+  long ru_ixrss;		/* integral shared memory size */
+  long ru_idrss;		/* integral unshared data size */
+  long ru_isrss;		/* integral unshared stack size */
+  long ru_minflt;		/* page reclaims */
+  long ru_majflt;		/* page faults */
+  long ru_nswap;		/* swaps */
+  long ru_inblock;		/* block input operations */
+  long ru_oublock;		/* block output operations */
+  long ru_msgsnd;		/* messages sent */
+  long ru_msgrcv;		/* messages received */
+  long ru_nsignals;		/* signals received */
+  long ru_nvcsw;		/* voluntary context switches */
+  long ru_nivcsw;		/* involuntary " */
+};
+
+static inline void
+rusage32_to_rusage64 (const struct __rusage32 *restrict r32,
+                    struct __rusage64 *restrict r64)
+{
+  /* Make sure the entire output structure is cleared, including
+     padding and reserved fields.  */
+  memset (r64, 0, sizeof *r64);
+
+  r64->ru_utime    = valid_timeval32_to_timeval64 (r32->ru_utime);
+  r64->ru_stime    = valid_timeval32_to_timeval64 (r32->ru_stime);
+  r64->ru_maxrss   = r32->ru_maxrss;
+  r64->ru_ixrss    = r32->ru_ixrss;
+  r64->ru_idrss    = r32->ru_idrss;
+  r64->ru_isrss    = r32->ru_isrss;
+  r64->ru_minflt   = r32->ru_minflt;
+  r64->ru_majflt   = r32->ru_majflt;
+  r64->ru_nswap    = r32->ru_nswap;
+  r64->ru_inblock  = r32->ru_inblock;
+  r64->ru_oublock  = r32->ru_oublock;
+  r64->ru_msgsnd   = r32->ru_msgsnd;
+  r64->ru_msgrcv   = r32->ru_msgrcv;
+  r64->ru_nsignals = r32->ru_nsignals;
+  r64->ru_nvcsw    = r32->ru_nvcsw;
+  r64->ru_nivcsw   = r32->ru_nivcsw;
+}
+
 #endif /* tv32-compat.h */

sysdeps/unix/sysv/linux/wait4.c

@@ -18,13 +18,28 @@
 
 #include <sys/wait.h>
 #include <sys/resource.h>
+#include <sys/types.h>
 #include <sysdep-cancel.h>
+#include <tv32-compat.h>
 
 pid_t
-__wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
+__wait4_time64 (pid_t pid, int *stat_loc, int options, struct __rusage64 *usage)
 {
 #ifdef __NR_wait4
+# if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
   return SYSCALL_CANCEL (wait4, pid, stat_loc, options, usage);
+# else
+  struct __rusage32 usage32;
+  pid_t ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, &usage32);
+
+  if (ret != 0)
+    return ret;
+
+  if (usage != NULL)
+    rusage32_to_rusage64 (&usage32, usage);
+
+  return ret;
+# endif
 #elif defined (__ASSUME_WAITID_PID0_P_PGID)
   idtype_t idtype = P_PID;
 
@@ -41,8 +56,19 @@ __wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
   options |= WEXITED;
 
   siginfo_t infop;
+
+# if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
   if (SYSCALL_CANCEL (waitid, idtype, pid, &infop, options, usage) < 0)
     return -1;
+# else
+  {
+    struct __rusage32 usage32;
+    if (SYSCALL_CANCEL (waitid, idtype, pid, &infop, options, &usage32) < 0)
+      return -1;
+    if (usage != NULL)
+      rusage32_to_rusage64 (&usage32, usage);
+  }
+# endif
 
   if (stat_loc)
     {
@@ -81,5 +107,25 @@ __wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
 # error "The kernel ABI does not provide a way to implement wait4"
 #endif
 }
+
+#if __TIMESIZE != 64
+libc_hidden_def (__wait4_time64)
+
+pid_t
+__wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
+{
+  pid_t ret ;
+  struct __rusage64 usage64;
+
+  ret = __wait4_time64 (pid, stat_loc, options, &usage64);
+
+  if (ret != 0)
+    return ret;
+
+  rusage64_to_rusage (&usage64, usage);
+
+  return ret;
+}
+#endif
 libc_hidden_def (__wait4);
 weak_alias (__wait4, wait4)