[PATCH 00/23] y2038 cleanups

[PATCH 00/23] y2038 cleanups

[Arnd Bergmann]

This is a series of cleanups for the y2038 work, mostly intended
for namespace cleaning: the kernel defines the traditional
time_t, timeval and timespec types that often lead to y2038-unsafe
code. Even though the unsafe usage is mostly gone from the kernel,
having the types and associated functions around means that we
can still grow new users, and that we may be missing conversions
to safe types that actually matter.

As there is no rush on any of these patches, I would either
queue them up in linux-next through my y2038 branch, or
Thomas could add them to the tip tree if he wants.

As mentioned in another series, this is part of a larger
effort to fix all the remaining bits and pieces that are
not completed yet from the y2038 conversion, and the full
set can be found at:

https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y2038-endgame

Maintainers, please review and provide Acks.

Let me know if you have any opinion on whether we should do
the include last two patches of this series or not.

     Arnd

Arnd Bergmann (23):
  y2038: remove CONFIG_64BIT_TIME
  y2038: add __kernel_old_timespec and __kernel_old_time_t
  y2038: vdso: change timeval to __kernel_old_timeval
  y2038: vdso: change timespec to __kernel_old_timespec
  y2038: vdso: change time_t to __kernel_old_time_t
  y2038: vdso: nds32: open-code timespec_add_ns()
  y2038: vdso: powerpc: avoid timespec references
  y2038: ipc: remove __kernel_time_t reference from headers
  y2038: stat: avoid 'time_t' in 'struct stat'
  y2038: uapi: change __kernel_time_t to __kernel_old_time_t
  y2038: rusage: use __kernel_old_timeval
  y2038: syscalls: change remaining timeval to __kernel_old_timeval
  y2038: socket: remove timespec reference in timestamping
  y2038: make ns_to_compat_timeval use __kernel_old_timeval
  y2038: elfcore: Use __kernel_old_timeval for process times
  y2038: timerfd: Use timespec64 internally
  y2038: time: avoid timespec usage in settimeofday()
  y2038: itimer: compat handling to itimer.c
  y2038: use compat_{get,set}_itimer on alpha
  y2038: move itimer reset into itimer.c
  y2038: itimer: change implementation to timespec64
  [RFC] y2038: itimer: use ktime_t internally
  y2038: allow disabling time32 system calls

 arch/Kconfig                              |  11 +-
 arch/alpha/kernel/osf_sys.c               |  67 +-----
 arch/alpha/kernel/syscalls/syscall.tbl    |   4 +-
 arch/ia64/kernel/asm-offsets.c            |   2 +-
 arch/mips/include/uapi/asm/msgbuf.h       |   6 +-
 arch/mips/include/uapi/asm/sembuf.h       |   4 +-
 arch/mips/include/uapi/asm/shmbuf.h       |   6 +-
 arch/mips/include/uapi/asm/stat.h         |  16 +-
 arch/mips/kernel/binfmt_elfn32.c          |   4 +-
 arch/mips/kernel/binfmt_elfo32.c          |   4 +-
 arch/nds32/kernel/vdso/gettimeofday.c     |  61 +++--
 arch/parisc/include/uapi/asm/msgbuf.h     |   6 +-
 arch/parisc/include/uapi/asm/sembuf.h     |   4 +-
 arch/parisc/include/uapi/asm/shmbuf.h     |   6 +-
 arch/powerpc/include/asm/asm-prototypes.h |   3 +-
 arch/powerpc/include/asm/vdso_datapage.h  |   6 +-
 arch/powerpc/include/uapi/asm/msgbuf.h    |   6 +-
 arch/powerpc/include/uapi/asm/sembuf.h    |   4 +-
 arch/powerpc/include/uapi/asm/shmbuf.h    |   6 +-
 arch/powerpc/include/uapi/asm/stat.h      |   2 +-
 arch/powerpc/kernel/asm-offsets.c         |  18 +-
 arch/powerpc/kernel/syscalls.c            |   4 +-
 arch/powerpc/kernel/time.c                |   5 +-
 arch/powerpc/kernel/vdso32/gettimeofday.S |   6 +-
 arch/powerpc/kernel/vdso64/gettimeofday.S |   8 +-
 arch/sparc/include/uapi/asm/msgbuf.h      |   6 +-
 arch/sparc/include/uapi/asm/sembuf.h      |   4 +-
 arch/sparc/include/uapi/asm/shmbuf.h      |   6 +-
 arch/sparc/include/uapi/asm/stat.h        |  24 +-
 arch/sparc/vdso/vclock_gettime.c          |  36 +--
 arch/x86/entry/vdso/vclock_gettime.c      |   6 +-
 arch/x86/entry/vsyscall/vsyscall_64.c     |   4 +-
 arch/x86/include/uapi/asm/msgbuf.h        |   6 +-
 arch/x86/include/uapi/asm/sembuf.h        |   4 +-
 arch/x86/include/uapi/asm/shmbuf.h        |   6 +-
 arch/x86/um/vdso/um_vdso.c                |  12 +-
 fs/aio.c                                  |   2 +-
 fs/binfmt_elf.c                           |  12 +-
 fs/binfmt_elf_fdpic.c                     |  12 +-
 fs/compat_binfmt_elf.c                    |   4 +-
 fs/select.c                               |  10 +-
 fs/timerfd.c                              |  14 +-
 fs/utimes.c                               |   8 +-
 include/linux/compat.h                    |  19 +-
 include/linux/syscalls.h                  |  16 +-
 include/linux/time.h                      |   9 +-
 include/linux/time32.h                    |   2 +-
 include/linux/types.h                     |   2 +-
 include/trace/events/timer.h              |  29 +--
 include/uapi/asm-generic/msgbuf.h         |  12 +-
 include/uapi/asm-generic/posix_types.h    |   1 +
 include/uapi/asm-generic/sembuf.h         |   7 +-
 include/uapi/asm-generic/shmbuf.h         |  12 +-
 include/uapi/linux/cyclades.h             |   6 +-
 include/uapi/linux/elfcore.h              |   8 +-
 include/uapi/linux/errqueue.h             |   7 +
 include/uapi/linux/msg.h                  |   6 +-
 include/uapi/linux/ppp_defs.h             |   4 +-
 include/uapi/linux/resource.h             |   4 +-
 include/uapi/linux/sem.h                  |   4 +-
 include/uapi/linux/shm.h                  |   6 +-
 include/uapi/linux/time.h                 |   6 +-
 include/uapi/linux/time_types.h           |   5 +
 include/uapi/linux/utime.h                |   4 +-
 ipc/syscall.c                             |   2 +-
 kernel/compat.c                           |  24 --
 kernel/power/power.h                      |   2 +-
 kernel/sys.c                              |   4 +-
 kernel/sys_ni.c                           |  23 ++
 kernel/time/hrtimer.c                     |   2 +-
 kernel/time/itimer.c                      | 280 ++++++++++++++--------
 kernel/time/time.c                        |  32 ++-
 lib/vdso/gettimeofday.c                   |   4 +-
 net/core/scm.c                            |   6 +-
 net/socket.c                              |   2 +-
 security/selinux/hooks.c                  |  10 +-
 76 files changed, 501 insertions(+), 504 deletions(-)

-- 
2.20.0

Cc: rth@twiddle.net
Cc: tony.luck@intel.com
Cc: paul.burton@mips.com
Cc: green.hu@gmail.com
Cc: deller@gmx.de
Cc: mpe@ellerman.id.au
Cc: davem@davemloft.net
Cc: tglx@linutronix.de
Cc: x86@kernel.org
Cc: jdike@addtoit.com
Cc: richard@nod.at
Cc: viro@zeniv.linux.org.uk
Cc: bcrl@kvack.org
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: rostedt@goodmis.org
Cc: arnd@arndb.de
Cc: vincenzo.frascino@arm.com
Cc: paul@paul-moore.com
Cc: sds@tycho.nsa.gov
Cc: eparis@parisplace.org
Cc: peterz@infradead.org
Cc: will@kernel.org
Cc: deepa.kernel@gmail.com
Cc: christian@brauner.io
Cc: heiko.carstens@de.ibm.com
Cc: christophe.leroy@c-s.fr
Cc: ebiederm@xmission.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-alpha@vger.kernel.org>
Cc: linux-ia64@vger.kernel.org>
Cc: linux-mips@vger.kernel.org>
Cc: linux-parisc@vger.kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org>
Cc: sparclinux@vger.kernel.org>
Cc: linux-um@lists.infradead.org>
Cc: linux-fsdevel@vger.kernel.org>
Cc: linux-aio@kvack.org>
Cc: linux-api@vger.kernel.org>
Cc: linux-arch@vger.kernel.org>
Cc: netdev@vger.kernel.org>
Cc: selinux@vger.kernel.org>

[PATCH 08/23] y2038: ipc: remove __kernel_time_t reference from headers

[Arnd Bergmann]

There are two structures based on time_t that conflict between libc and
kernel: timeval and timespec. Both are now renamed to __kernel_old_timeval
and __kernel_old_timespec.

For time_t, the old typedef is still __kernel_time_t. There is nothing
wrong with that name, but it would be nice to not use that going forward
as this type is used almost only in deprecated interfaces because of
the y2038 overflow.

In the IPC headers (msgbuf.h, sembuf.h, shmbuf.h), __kernel_time_t is only
used for the 64-bit variants, which are not deprecated.

Change these to a plain 'long', which is the same type as __kernel_time_t
on all 64-bit architectures anyway, to reduce the number of users of the
old type.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/include/uapi/asm/msgbuf.h    |  6 +++---
 arch/mips/include/uapi/asm/sembuf.h    |  4 ++--
 arch/mips/include/uapi/asm/shmbuf.h    |  6 +++---
 arch/parisc/include/uapi/asm/msgbuf.h  |  6 +++---
 arch/parisc/include/uapi/asm/sembuf.h  |  4 ++--
 arch/parisc/include/uapi/asm/shmbuf.h  |  6 +++---
 arch/powerpc/include/uapi/asm/msgbuf.h |  6 +++---
 arch/powerpc/include/uapi/asm/sembuf.h |  4 ++--
 arch/powerpc/include/uapi/asm/shmbuf.h |  6 +++---
 arch/sparc/include/uapi/asm/msgbuf.h   |  6 +++---
 arch/sparc/include/uapi/asm/sembuf.h   |  4 ++--
 arch/sparc/include/uapi/asm/shmbuf.h   |  6 +++---
 arch/x86/include/uapi/asm/msgbuf.h     |  6 +++---
 arch/x86/include/uapi/asm/sembuf.h     |  4 ++--
 arch/x86/include/uapi/asm/shmbuf.h     |  6 +++---
 include/uapi/asm-generic/msgbuf.h      | 12 ++++++------
 include/uapi/asm-generic/sembuf.h      |  7 +++----
 include/uapi/asm-generic/shmbuf.h      | 12 ++++++------
 18 files changed, 55 insertions(+), 56 deletions(-)

diff --git a/arch/mips/include/uapi/asm/msgbuf.h b/arch/mips/include/uapi/asm/msgbuf.h
index 46aa15b13e4e..9e0c2e230274 100644
--- a/arch/mips/include/uapi/asm/msgbuf.h
+++ b/arch/mips/include/uapi/asm/msgbuf.h
@@ -15,9 +15,9 @@
 #if defined(__mips64)
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
+	long msg_stime;			/* last msgsnd time */
+	long msg_rtime;			/* last msgrcv time */
+	long msg_ctime;			/* last change time */
 	unsigned long  msg_cbytes;	/* current number of bytes on queue */
 	unsigned long  msg_qnum;	/* number of messages in queue */
 	unsigned long  msg_qbytes;	/* max number of bytes on queue */
diff --git a/arch/mips/include/uapi/asm/sembuf.h b/arch/mips/include/uapi/asm/sembuf.h
index 60c89e6cb25b..43e1b4a2f68a 100644
--- a/arch/mips/include/uapi/asm/sembuf.h
+++ b/arch/mips/include/uapi/asm/sembuf.h
@@ -14,8 +14,8 @@
 #ifdef __mips64
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
-	__kernel_time_t sem_otime;		/* last semop time */
-	__kernel_time_t sem_ctime;		/* last change time */
+	long		 sem_otime;		/* last semop time */
+	long		 sem_ctime;		/* last change time */
 	unsigned long	sem_nsems;		/* no. of semaphores in array */
 	unsigned long	__unused1;
 	unsigned long	__unused2;
diff --git a/arch/mips/include/uapi/asm/shmbuf.h b/arch/mips/include/uapi/asm/shmbuf.h
index 9b9bba3401f2..680bb95b2240 100644
--- a/arch/mips/include/uapi/asm/shmbuf.h
+++ b/arch/mips/include/uapi/asm/shmbuf.h
@@ -17,9 +17,9 @@
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
+	long			shm_atime;	/* last attach time */
+	long			shm_dtime;	/* last detach time */
+	long			shm_ctime;	/* last change time */
 	__kernel_pid_t		shm_cpid;	/* pid of creator */
 	__kernel_pid_t		shm_lpid;	/* pid of last operator */
 	unsigned long		shm_nattch;	/* no. of current attaches */
diff --git a/arch/parisc/include/uapi/asm/msgbuf.h b/arch/parisc/include/uapi/asm/msgbuf.h
index 6a2e9ab2ef8d..3b877335da38 100644
--- a/arch/parisc/include/uapi/asm/msgbuf.h
+++ b/arch/parisc/include/uapi/asm/msgbuf.h
@@ -16,9 +16,9 @@
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
 #if __BITS_PER_LONG == 64
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
+	long		 msg_stime;	/* last msgsnd time */
+	long		 msg_rtime;	/* last msgrcv time */
+	long		 msg_ctime;	/* last change time */
 #else
 	unsigned long	msg_stime_high;
 	unsigned long	msg_stime;	/* last msgsnd time */
diff --git a/arch/parisc/include/uapi/asm/sembuf.h b/arch/parisc/include/uapi/asm/sembuf.h
index 3c31163b1241..8241cf126018 100644
--- a/arch/parisc/include/uapi/asm/sembuf.h
+++ b/arch/parisc/include/uapi/asm/sembuf.h
@@ -16,8 +16,8 @@
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
 #if __BITS_PER_LONG == 64
-	__kernel_time_t	sem_otime;		/* last semop time */
-	__kernel_time_t	sem_ctime;		/* last change time */
+	long		sem_otime;		/* last semop time */
+	long		sem_ctime;		/* last change time */
 #else
 	unsigned long	sem_otime_high;
 	unsigned long	sem_otime;		/* last semop time */
diff --git a/arch/parisc/include/uapi/asm/shmbuf.h b/arch/parisc/include/uapi/asm/shmbuf.h
index c89b3dd8db21..5da3089be65e 100644
--- a/arch/parisc/include/uapi/asm/shmbuf.h
+++ b/arch/parisc/include/uapi/asm/shmbuf.h
@@ -16,9 +16,9 @@
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 #if __BITS_PER_LONG == 64
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
+	long			shm_atime;	/* last attach time */
+	long			shm_dtime;	/* last detach time */
+	long			shm_ctime;	/* last change time */
 #else
 	unsigned long		shm_atime_high;
 	unsigned long		shm_atime;	/* last attach time */
diff --git a/arch/powerpc/include/uapi/asm/msgbuf.h b/arch/powerpc/include/uapi/asm/msgbuf.h
index 2b1b37797a47..969bd83e4d3d 100644
--- a/arch/powerpc/include/uapi/asm/msgbuf.h
+++ b/arch/powerpc/include/uapi/asm/msgbuf.h
@@ -11,9 +11,9 @@
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
 #ifdef __powerpc64__
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
+	long		 msg_stime;	/* last msgsnd time */
+	long		 msg_rtime;	/* last msgrcv time */
+	long		 msg_ctime;	/* last change time */
 #else
 	unsigned long  msg_stime_high;
 	unsigned long  msg_stime;	/* last msgsnd time */
diff --git a/arch/powerpc/include/uapi/asm/sembuf.h b/arch/powerpc/include/uapi/asm/sembuf.h
index 3f60946f77e3..008ae77c6746 100644
--- a/arch/powerpc/include/uapi/asm/sembuf.h
+++ b/arch/powerpc/include/uapi/asm/sembuf.h
@@ -26,8 +26,8 @@ struct semid64_ds {
 	unsigned long	sem_ctime_high;
 	unsigned long	sem_ctime;	/* last change time */
 #else
-	__kernel_time_t	sem_otime;	/* last semop time */
-	__kernel_time_t	sem_ctime;	/* last change time */
+	long		sem_otime;	/* last semop time */
+	long		sem_ctime;	/* last change time */
 #endif
 	unsigned long	sem_nsems;	/* no. of semaphores in array */
 	unsigned long	__unused3;
diff --git a/arch/powerpc/include/uapi/asm/shmbuf.h b/arch/powerpc/include/uapi/asm/shmbuf.h
index b591c4d7e4c5..00422b2f3c63 100644
--- a/arch/powerpc/include/uapi/asm/shmbuf.h
+++ b/arch/powerpc/include/uapi/asm/shmbuf.h
@@ -22,9 +22,9 @@
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 #ifdef __powerpc64__
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
+	long		shm_atime;	/* last attach time */
+	long		shm_dtime;	/* last detach time */
+	long		shm_ctime;	/* last change time */
 #else
 	unsigned long		shm_atime_high;
 	unsigned long		shm_atime;	/* last attach time */
diff --git a/arch/sparc/include/uapi/asm/msgbuf.h b/arch/sparc/include/uapi/asm/msgbuf.h
index ffc46c211d6d..eeeb91933280 100644
--- a/arch/sparc/include/uapi/asm/msgbuf.h
+++ b/arch/sparc/include/uapi/asm/msgbuf.h
@@ -13,9 +13,9 @@
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
 #if defined(__sparc__) && defined(__arch64__)
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
+	long msg_stime;			/* last msgsnd time */
+	long msg_rtime;			/* last msgrcv time */
+	long msg_ctime;			/* last change time */
 #else
 	unsigned long msg_stime_high;
 	unsigned long msg_stime;	/* last msgsnd time */
diff --git a/arch/sparc/include/uapi/asm/sembuf.h b/arch/sparc/include/uapi/asm/sembuf.h
index f3d309c2e1cd..cbcbaa4e7128 100644
--- a/arch/sparc/include/uapi/asm/sembuf.h
+++ b/arch/sparc/include/uapi/asm/sembuf.h
@@ -14,8 +14,8 @@
 struct semid64_ds {
 	struct ipc64_perm sem_perm;		/* permissions .. see ipc.h */
 #if defined(__sparc__) && defined(__arch64__)
-	__kernel_time_t	sem_otime;		/* last semop time */
-	__kernel_time_t	sem_ctime;		/* last change time */
+	long		sem_otime;		/* last semop time */
+	long		sem_ctime;		/* last change time */
 #else
 	unsigned long	sem_otime_high;
 	unsigned long	sem_otime;		/* last semop time */
diff --git a/arch/sparc/include/uapi/asm/shmbuf.h b/arch/sparc/include/uapi/asm/shmbuf.h
index 06618b84822d..a5d7d8d681c4 100644
--- a/arch/sparc/include/uapi/asm/shmbuf.h
+++ b/arch/sparc/include/uapi/asm/shmbuf.h
@@ -14,9 +14,9 @@
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 #if defined(__sparc__) && defined(__arch64__)
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
+	long			shm_atime;	/* last attach time */
+	long			shm_dtime;	/* last detach time */
+	long			shm_ctime;	/* last change time */
 #else
 	unsigned long		shm_atime_high;
 	unsigned long		shm_atime;	/* last attach time */
diff --git a/arch/x86/include/uapi/asm/msgbuf.h b/arch/x86/include/uapi/asm/msgbuf.h
index 90ab9a795b49..7c5bb43ed8af 100644
--- a/arch/x86/include/uapi/asm/msgbuf.h
+++ b/arch/x86/include/uapi/asm/msgbuf.h
@@ -15,9 +15,9 @@
 
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
+	__kernel_long_t msg_stime;	/* last msgsnd time */
+	__kernel_long_t msg_rtime;	/* last msgrcv time */
+	__kernel_long_t msg_ctime;	/* last change time */
 	__kernel_ulong_t msg_cbytes;	/* current number of bytes on queue */
 	__kernel_ulong_t msg_qnum;	/* number of messages in queue */
 	__kernel_ulong_t msg_qbytes;	/* max number of bytes on queue */
diff --git a/arch/x86/include/uapi/asm/sembuf.h b/arch/x86/include/uapi/asm/sembuf.h
index 89de6cd9f0a7..7c1b156695ba 100644
--- a/arch/x86/include/uapi/asm/sembuf.h
+++ b/arch/x86/include/uapi/asm/sembuf.h
@@ -21,9 +21,9 @@ struct semid64_ds {
 	unsigned long	sem_ctime;	/* last change time */
 	unsigned long	sem_ctime_high;
 #else
-	__kernel_time_t	sem_otime;	/* last semop time */
+	long		sem_otime;	/* last semop time */
 	__kernel_ulong_t __unused1;
-	__kernel_time_t	sem_ctime;	/* last change time */
+	long		sem_ctime;	/* last change time */
 	__kernel_ulong_t __unused2;
 #endif
 	__kernel_ulong_t sem_nsems;	/* no. of semaphores in array */
diff --git a/arch/x86/include/uapi/asm/shmbuf.h b/arch/x86/include/uapi/asm/shmbuf.h
index 644421f3823b..f0305dc660c9 100644
--- a/arch/x86/include/uapi/asm/shmbuf.h
+++ b/arch/x86/include/uapi/asm/shmbuf.h
@@ -16,9 +16,9 @@
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 	size_t			shm_segsz;	/* size of segment (bytes) */
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
+	__kernel_long_t		shm_atime;	/* last attach time */
+	__kernel_long_t		shm_dtime;	/* last detach time */
+	__kernel_long_t		shm_ctime;	/* last change time */
 	__kernel_pid_t		shm_cpid;	/* pid of creator */
 	__kernel_pid_t		shm_lpid;	/* pid of last operator */
 	__kernel_ulong_t	shm_nattch;	/* no. of current attaches */
diff --git a/include/uapi/asm-generic/msgbuf.h b/include/uapi/asm-generic/msgbuf.h
index 9fe4881557cb..af95aa89012e 100644
--- a/include/uapi/asm-generic/msgbuf.h
+++ b/include/uapi/asm-generic/msgbuf.h
@@ -13,9 +13,9 @@
  * everyone just ended up making identical copies without specific
  * optimizations, so we may just as well all use the same one.
  *
- * 64 bit architectures typically define a 64 bit __kernel_time_t,
- * so they do not need the first three padding words.
- * On big-endian systems, the padding is in the wrong place.
+ * 64 bit architectures use a 64-bit long time field here, while
+ * 32 bit architectures have a pair of unsigned long values.
+ * On big-endian systems, the lower half is in the wrong place.
  *
  * Pad space is left for:
  * - 2 miscellaneous 32-bit values
@@ -24,9 +24,9 @@
 struct msqid64_ds {
 	struct ipc64_perm msg_perm;
 #if __BITS_PER_LONG == 64
-	__kernel_time_t msg_stime;	/* last msgsnd time */
-	__kernel_time_t msg_rtime;	/* last msgrcv time */
-	__kernel_time_t msg_ctime;	/* last change time */
+	long		 msg_stime;	/* last msgsnd time */
+	long		 msg_rtime;	/* last msgrcv time */
+	long		 msg_ctime;	/* last change time */
 #else
 	unsigned long	msg_stime;	/* last msgsnd time */
 	unsigned long	msg_stime_high;
diff --git a/include/uapi/asm-generic/sembuf.h b/include/uapi/asm-generic/sembuf.h
index 0bae010f1b64..137606018c6a 100644
--- a/include/uapi/asm-generic/sembuf.h
+++ b/include/uapi/asm-generic/sembuf.h
@@ -13,9 +13,8 @@
  * everyone just ended up making identical copies without specific
  * optimizations, so we may just as well all use the same one.
  *
- * 64 bit architectures use a 64-bit __kernel_time_t here, while
+ * 64 bit architectures use a 64-bit long time field here, while
  * 32 bit architectures have a pair of unsigned long values.
- * so they do not need the first two padding words.
  *
  * On big-endian systems, the padding is in the wrong place for
  * historic reasons, so user space has to reconstruct a time_t
@@ -29,8 +28,8 @@
 struct semid64_ds {
 	struct ipc64_perm sem_perm;	/* permissions .. see ipc.h */
 #if __BITS_PER_LONG == 64
-	__kernel_time_t	sem_otime;	/* last semop time */
-	__kernel_time_t	sem_ctime;	/* last change time */
+	long		sem_otime;	/* last semop time */
+	long		sem_ctime;	/* last change time */
 #else
 	unsigned long	sem_otime;	/* last semop time */
 	unsigned long	sem_otime_high;
diff --git a/include/uapi/asm-generic/shmbuf.h b/include/uapi/asm-generic/shmbuf.h
index e504422fc501..2bab955e0fed 100644
--- a/include/uapi/asm-generic/shmbuf.h
+++ b/include/uapi/asm-generic/shmbuf.h
@@ -13,9 +13,9 @@
  * everyone just ended up making identical copies without specific
  * optimizations, so we may just as well all use the same one.
  *
- * 64 bit architectures typically define a 64 bit __kernel_time_t,
- * so they do not need the first two padding words.
- * On big-endian systems, the padding is in the wrong place.
+ * 64 bit architectures use a 64-bit long time field here, while
+ * 32 bit architectures have a pair of unsigned long values.
+ * On big-endian systems, the lower half is in the wrong place.
  *
  *
  * Pad space is left for:
@@ -26,9 +26,9 @@ struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
 	size_t			shm_segsz;	/* size of segment (bytes) */
 #if __BITS_PER_LONG == 64
-	__kernel_time_t		shm_atime;	/* last attach time */
-	__kernel_time_t		shm_dtime;	/* last detach time */
-	__kernel_time_t		shm_ctime;	/* last change time */
+	long			shm_atime;	/* last attach time */
+	long			shm_dtime;	/* last detach time */
+	long			shm_ctime;	/* last change time */
 #else
 	unsigned long		shm_atime;	/* last attach time */
 	unsigned long		shm_atime_high;
-- 
2.20.0

[PATCH 09/23] y2038: stat: avoid 'time_t' in 'struct stat'

[Arnd Bergmann]

The time_t definition may differ between user space and kernel space,
so replace time_t with an unambiguous 'long' for the mips and sparc.

The same structures also contain 'off_t', which has the same problem,
so replace that as well on those two architectures and powerpc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/include/uapi/asm/stat.h    | 16 ++++++++--------
 arch/powerpc/include/uapi/asm/stat.h |  2 +-
 arch/sparc/include/uapi/asm/stat.h   | 24 ++++++++++++------------
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/arch/mips/include/uapi/asm/stat.h b/arch/mips/include/uapi/asm/stat.h
index 95416f366d7f..3d2a3b71845c 100644
--- a/arch/mips/include/uapi/asm/stat.h
+++ b/arch/mips/include/uapi/asm/stat.h
@@ -26,17 +26,17 @@ struct stat {
 	gid_t		st_gid;
 	unsigned	st_rdev;
 	long		st_pad2[2];
-	off_t		st_size;
+	long		st_size;
 	long		st_pad3;
 	/*
 	 * Actually this should be timestruc_t st_atime, st_mtime and st_ctime
 	 * but we don't have it under Linux.
 	 */
-	time_t		st_atime;
+	long		st_atime;
 	long		st_atime_nsec;
-	time_t		st_mtime;
+	long		st_mtime;
 	long		st_mtime_nsec;
-	time_t		st_ctime;
+	long		st_ctime;
 	long		st_ctime_nsec;
 	long		st_blksize;
 	long		st_blocks;
@@ -70,13 +70,13 @@ struct stat64 {
 	 * Actually this should be timestruc_t st_atime, st_mtime and st_ctime
 	 * but we don't have it under Linux.
 	 */
-	time_t		st_atime;
+	long		st_atime;
 	unsigned long	st_atime_nsec;	/* Reserved for st_atime expansion  */
 
-	time_t		st_mtime;
+	long		st_mtime;
 	unsigned long	st_mtime_nsec;	/* Reserved for st_mtime expansion  */
 
-	time_t		st_ctime;
+	long		st_ctime;
 	unsigned long	st_ctime_nsec;	/* Reserved for st_ctime expansion  */
 
 	unsigned long	st_blksize;
@@ -105,7 +105,7 @@ struct stat {
 	unsigned int		st_rdev;
 	unsigned int		st_pad1[3]; /* Reserved for st_rdev expansion */
 
-	off_t			st_size;
+	long			st_size;
 
 	/*
 	 * Actually this should be timestruc_t st_atime, st_mtime and st_ctime
diff --git a/arch/powerpc/include/uapi/asm/stat.h b/arch/powerpc/include/uapi/asm/stat.h
index afd25f2ff4e8..7871055e5e32 100644
--- a/arch/powerpc/include/uapi/asm/stat.h
+++ b/arch/powerpc/include/uapi/asm/stat.h
@@ -40,7 +40,7 @@ struct stat {
 	uid_t		st_uid;
 	gid_t		st_gid;
 	unsigned long	st_rdev;
-	off_t		st_size;
+	long		st_size;
 	unsigned long	st_blksize;
 	unsigned long	st_blocks;
 	unsigned long	st_atime;
diff --git a/arch/sparc/include/uapi/asm/stat.h b/arch/sparc/include/uapi/asm/stat.h
index b6ec4eb217f7..732c41720e24 100644
--- a/arch/sparc/include/uapi/asm/stat.h
+++ b/arch/sparc/include/uapi/asm/stat.h
@@ -14,12 +14,12 @@ struct stat {
 	uid_t   st_uid;
 	gid_t   st_gid;
 	unsigned int st_rdev;
-	off_t   st_size;
-	time_t  st_atime;
-	time_t  st_mtime;
-	time_t  st_ctime;
-	off_t   st_blksize;
-	off_t   st_blocks;
+	long    st_size;
+	long    st_atime;
+	long    st_mtime;
+	long    st_ctime;
+	long    st_blksize;
+	long    st_blocks;
 	unsigned long  __unused4[2];
 };
 
@@ -57,15 +57,15 @@ struct stat {
 	unsigned short	st_uid;
 	unsigned short	st_gid;
 	unsigned short	st_rdev;
-	off_t		st_size;
-	time_t		st_atime;
+	long		st_size;
+	long		st_atime;
 	unsigned long	st_atime_nsec;
-	time_t		st_mtime;
+	long		st_mtime;
 	unsigned long	st_mtime_nsec;
-	time_t		st_ctime;
+	long		st_ctime;
 	unsigned long	st_ctime_nsec;
-	off_t		st_blksize;
-	off_t		st_blocks;
+	long		st_blksize;
+	long		st_blocks;
 	unsigned long	__unused4[2];
 };
 
-- 
2.20.0

[PATCH 15/23] y2038: elfcore: Use __kernel_old_timeval for process times

[Arnd Bergmann]

We store elapsed time for a crashed process in struct elf_prstatus using
'timeval' structures. Once glibc starts using 64-bit time_t, this becomes
incompatible with the kernel's idea of timeval since the structure layout
no longer matches on 32-bit architectures.

This changes the definition of the elf_prstatus structure to use
__kernel_old_timeval instead, which is hardcoded to the currently used
binary layout. There is no risk of overflow in y2038 though, because
the time values are all relative times, and can store up to 68 years
of process elapsed time.

There is a risk of applications breaking at build time when they
use the new kernel headers and expect the type to be exactly 'timeval'
rather than a structure that has the same fields as before. Those
applications have to be modified to deal with 64-bit time_t anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/kernel/binfmt_elfn32.c |  4 ++--
 arch/mips/kernel/binfmt_elfo32.c |  4 ++--
 fs/binfmt_elf.c                  | 12 ++++++------
 fs/binfmt_elf_fdpic.c            | 12 ++++++------
 fs/compat_binfmt_elf.c           |  4 ++--
 include/uapi/linux/elfcore.h     |  8 ++++----
 6 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 7a12763d553a..6ee3f7218c67 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -100,7 +100,7 @@ jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
 #undef TASK_SIZE
 #define TASK_SIZE TASK_SIZE32
 
-#undef ns_to_timeval
-#define ns_to_timeval ns_to_old_timeval32
+#undef ns_to_kernel_old_timeval
+#define ns_to_kernel_old_timeval ns_to_old_timeval32
 
 #include "../../../fs/binfmt_elf.c"
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index e6db06a1d31a..6dd103d3cebb 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -103,7 +103,7 @@ jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
 #undef TASK_SIZE
 #define TASK_SIZE TASK_SIZE32
 
-#undef ns_to_timeval
-#define ns_to_timeval ns_to_old_timeval32
+#undef ns_to_kernel_old_timeval
+#define ns_to_kernel_old_timeval ns_to_old_timeval32
 
 #include "../../../fs/binfmt_elf.c"
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index c5642bcb6b46..5372eabd276a 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1489,18 +1489,18 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 		 * group-wide total, not its individual thread total.
 		 */
 		thread_group_cputime(p, &cputime);
-		prstatus->pr_utime = ns_to_timeval(cputime.utime);
-		prstatus->pr_stime = ns_to_timeval(cputime.stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
 	} else {
 		u64 utime, stime;
 
 		task_cputime(p, &utime, &stime);
-		prstatus->pr_utime = ns_to_timeval(utime);
-		prstatus->pr_stime = ns_to_timeval(stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
 	}
 
-	prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
-	prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
+	prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
+	prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
 }
 
 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index d86ebd0dcc3d..240f66663543 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1359,17 +1359,17 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 		 * group-wide total, not its individual thread total.
 		 */
 		thread_group_cputime(p, &cputime);
-		prstatus->pr_utime = ns_to_timeval(cputime.utime);
-		prstatus->pr_stime = ns_to_timeval(cputime.stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
 	} else {
 		u64 utime, stime;
 
 		task_cputime(p, &utime, &stime);
-		prstatus->pr_utime = ns_to_timeval(utime);
-		prstatus->pr_stime = ns_to_timeval(stime);
+		prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
+		prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
 	}
-	prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
-	prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
+	prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
+	prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
 
 	prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
 	prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index b7f9ffa1d5f1..aaad4ca1217e 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -48,8 +48,8 @@
 #define elf_prstatus	compat_elf_prstatus
 #define elf_prpsinfo	compat_elf_prpsinfo
 
-#undef ns_to_timeval
-#define ns_to_timeval ns_to_old_timeval32
+#undef ns_to_kernel_old_timeval
+#define ns_to_kernel_old_timeval ns_to_old_timeval32
 
 /*
  * To use this file, asm/elf.h must define compat_elf_check_arch.
diff --git a/include/uapi/linux/elfcore.h b/include/uapi/linux/elfcore.h
index 0b2c9e16e345..baf03562306d 100644
--- a/include/uapi/linux/elfcore.h
+++ b/include/uapi/linux/elfcore.h
@@ -53,10 +53,10 @@ struct elf_prstatus
 	pid_t	pr_ppid;
 	pid_t	pr_pgrp;
 	pid_t	pr_sid;
-	struct timeval pr_utime;	/* User time */
-	struct timeval pr_stime;	/* System time */
-	struct timeval pr_cutime;	/* Cumulative user time */
-	struct timeval pr_cstime;	/* Cumulative system time */
+	struct __kernel_old_timeval pr_utime;	/* User time */
+	struct __kernel_old_timeval pr_stime;	/* System time */
+	struct __kernel_old_timeval pr_cutime;	/* Cumulative user time */
+	struct __kernel_old_timeval pr_cstime;	/* Cumulative system time */
 #if 0
 	long	pr_instr;		/* Current instruction */
 #endif
-- 
2.20.0

Re: [PATCH 00/23] y2038 cleanups

[Arnd Bergmann]

On Fri, Nov 8, 2019 at 10:04 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> This is a series of cleanups for the y2038 work, mostly intended
> for namespace cleaning: the kernel defines the traditional
> time_t, timeval and timespec types that often lead to y2038-unsafe
> code. Even though the unsafe usage is mostly gone from the kernel,
> having the types and associated functions around means that we
> can still grow new users, and that we may be missing conversions
> to safe types that actually matter.
>
> As there is no rush on any of these patches, I would either
> queue them up in linux-next through my y2038 branch, or
> Thomas could add them to the tip tree if he wants.
>
> As mentioned in another series, this is part of a larger
> effort to fix all the remaining bits and pieces that are
> not completed yet from the y2038 conversion, and the full
> set can be found at:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y2038-endgame
>
> Maintainers, please review and provide Acks.
>
> Let me know if you have any opinion on whether we should do
> the include last two patches of this series or not.
>
>      Arnd
>
> Arnd Bergmann (23):
>   y2038: remove CONFIG_64BIT_TIME
>   y2038: add __kernel_old_timespec and __kernel_old_time_t
>   y2038: vdso: change timeval to __kernel_old_timeval
>   y2038: vdso: change timespec to __kernel_old_timespec
>   y2038: vdso: change time_t to __kernel_old_time_t
>   y2038: vdso: nds32: open-code timespec_add_ns()
>   y2038: vdso: powerpc: avoid timespec references
>   y2038: ipc: remove __kernel_time_t reference from headers
>   y2038: stat: avoid 'time_t' in 'struct stat'
>   y2038: uapi: change __kernel_time_t to __kernel_old_time_t
>   y2038: rusage: use __kernel_old_timeval
>   y2038: syscalls: change remaining timeval to __kernel_old_timeval
>   y2038: socket: remove timespec reference in timestamping
>   y2038: make ns_to_compat_timeval use __kernel_old_timeval
>   y2038: elfcore: Use __kernel_old_timeval for process times
>   y2038: timerfd: Use timespec64 internally
>   y2038: time: avoid timespec usage in settimeofday()
>   y2038: itimer: compat handling to itimer.c
>   y2038: use compat_{get,set}_itimer on alpha
>   y2038: move itimer reset into itimer.c
>   y2038: itimer: change implementation to timespec64
>   [RFC] y2038: itimer: use ktime_t internally
>   y2038: allow disabling time32 system calls

I've dropped the "[RFC] y2038: itimer: use ktime_t internally" patch
for the moment,
and added two other patches from other series:

y2038: remove CONFIG_64BIT_TIME
y2038: socket: use __kernel_old_timespec instead of timespec

Tentatively pushed out the patches with the Acks I have received so
far to my y2038 branch on git.kernel.org so it gets included in linux-next.

If I hear no complaints, I'll send a pull request for the merge window,
along with the compat-ioctl series I have already queued up in the same
branch.

    Arnd

Re: [Y2038] [PATCH 08/23] y2038: ipc: remove __kernel_time_t reference from headers

[Ben Hutchings]

On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
[...]
> --- a/arch/x86/include/uapi/asm/sembuf.h
> +++ b/arch/x86/include/uapi/asm/sembuf.h
> @@ -21,9 +21,9 @@ struct semid64_ds {
>  	unsigned long	sem_ctime;	/* last change time */
>  	unsigned long	sem_ctime_high;
>  #else
> -	__kernel_time_t	sem_otime;	/* last semop time */
> +	long		sem_otime;	/* last semop time */
>  	__kernel_ulong_t __unused1;
> -	__kernel_time_t	sem_ctime;	/* last change time */
> +	long		sem_ctime;	/* last change time */
>  	__kernel_ulong_t __unused2;
>  #endif
>  	__kernel_ulong_t sem_nsems;	/* no. of semaphores in array */
[...]

We need to use __kernel_long_t here to do the right thing on x32.

Ben.

-- 
Ben Hutchings, Software Developer                         Codethink Ltd
https://www.codethink.co.uk/                 Dale House, 35 Dale Street
                                     Manchester, M1 2HF, United Kingdom

Re: [Y2038] [PATCH 08/23] y2038: ipc: remove __kernel_time_t reference from headers

[Arnd Bergmann]

On Wed, Nov 20, 2019 at 11:49 PM Ben Hutchings
<ben.hutchings@codethink.co.uk> wrote:
>
> On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
> [...]
> > --- a/arch/x86/include/uapi/asm/sembuf.h
> > +++ b/arch/x86/include/uapi/asm/sembuf.h
> > @@ -21,9 +21,9 @@ struct semid64_ds {
> >       unsigned long   sem_ctime;      /* last change time */
> >       unsigned long   sem_ctime_high;
> >  #else
> > -     __kernel_time_t sem_otime;      /* last semop time */
> > +     long            sem_otime;      /* last semop time */
> >       __kernel_ulong_t __unused1;
> > -     __kernel_time_t sem_ctime;      /* last change time */
> > +     long            sem_ctime;      /* last change time */
> >       __kernel_ulong_t __unused2;
> >  #endif
> >       __kernel_ulong_t sem_nsems;     /* no. of semaphores in array */
> [...]
>
> We need to use __kernel_long_t here to do the right thing on x32.

Good catch, thanks for the review!

I applied the patch below now on top.

       Arnd

commit c7ebd8a1c1825c3197732ea692cf3dde34a644f5 (HEAD)
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Thu Nov 21 15:25:04 2019 +0100

    y2038: ipc: fix x32 ABI breakage

    The correct type on x32 is 64-bit wide, same as for the other struct
    members around it, so use  __kernel_long_t in place of the original
    __kernel_time_t here, corresponding to the rest of the structure.

    Fixes: caf5e32d4ea7 ("y2038: ipc: remove __kernel_time_t reference
from headers")
    Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
    Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/x86/include/uapi/asm/sembuf.h
b/arch/x86/include/uapi/asm/sembuf.h
index 7c1b156695ba..20cab43c4b15 100644
--- a/arch/x86/include/uapi/asm/sembuf.h
+++ b/arch/x86/include/uapi/asm/sembuf.h
@@ -21,9 +21,9 @@ struct semid64_ds {
        unsigned long   sem_ctime;      /* last change time */
        unsigned long   sem_ctime_high;
 #else
-       long            sem_otime;      /* last semop time */
+       __kernel_long_t sem_otime;      /* last semop time */
        __kernel_ulong_t __unused1;
-       long            sem_ctime;      /* last change time */
+       __kenrel_long_t sem_ctime;      /* last change time */
        __kernel_ulong_t __unused2;
 #endif
        __kernel_ulong_t sem_nsems;     /* no. of semaphores in array */