[PATCH 00/23] y2038 cleanups

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>

The CONFIG_64BIT_TIME option is defined on all architectures, and can
be removed for simplicity now.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/Kconfig          | 8 --------
 fs/aio.c              | 2 +-
 ipc/syscall.c         | 2 +-
 kernel/time/hrtimer.c | 2 +-
 kernel/time/time.c    | 4 ++--
 net/socket.c          | 2 +-
 6 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 5f8a5d84dbbe..0e1fded2940e 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig

@@ -796,14 +796,6 @@ config OLD_SIGACTION
 config COMPAT_OLD_SIGACTION
 	bool
 
-config 64BIT_TIME
-	def_bool y
-	help
-	  This should be selected by all architectures that need to support
-	  new system calls with a 64-bit time_t. This is relevant on all 32-bit
-	  architectures, and 64-bit architectures as part of compat syscall
-	  handling.
-
 config COMPAT_32BIT_TIME
 	def_bool !64BIT || COMPAT
 	help

diff --git a/fs/aio.c b/fs/aio.c
index 01e0fb9ae45a..447e3a0c572c 100644
--- a/fs/aio.c
+++ b/fs/aio.c

@@ -2056,7 +2056,7 @@ static long do_io_getevents(aio_context_t ctx_id,
  *	specifies an infinite timeout. Note that the timeout pointed to by
  *	timeout is relative.  Will fail with -ENOSYS if not implemented.
  */
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 
 SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
 		long, min_nr,

diff --git a/ipc/syscall.c b/ipc/syscall.c
index 581bdff4e7c5..dfb0e988d542 100644
--- a/ipc/syscall.c
+++ b/ipc/syscall.c

@@ -30,7 +30,7 @@ int ksys_ipc(unsigned int call, int first, unsigned long second,
 		return ksys_semtimedop(first, (struct sembuf __user *)ptr,
 				       second, NULL);
 	case SEMTIMEDOP:
-		if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
+		if (IS_ENABLED(CONFIG_64BIT))
 			return ksys_semtimedop(first, ptr, second,
 			        (const struct __kernel_timespec __user *)fifth);
 		else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 65605530ee34..9e20873148c6 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c

@@ -1940,7 +1940,7 @@ long hrtimer_nanosleep(const struct timespec64 *rqtp,
 	return ret;
 }
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 
 SYSCALL_DEFINE2(nanosleep, struct __kernel_timespec __user *, rqtp,
 		struct __kernel_timespec __user *, rmtp)

diff --git a/kernel/time/time.c b/kernel/time/time.c
index 45a358953f09..ddbddf504c23 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c

@@ -267,7 +267,7 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
 }
 #endif
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
 {
 	struct __kernel_timex txc;		/* Local copy of parameter */

@@ -884,7 +884,7 @@ int get_timespec64(struct timespec64 *ts,
 	ts->tv_sec = kts.tv_sec;
 
 	/* Zero out the padding for 32 bit systems or in compat mode */
-	if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall())
+	if (in_compat_syscall())
 		kts.tv_nsec &= 0xFFFFFFFFUL;
 
 	ts->tv_nsec = kts.tv_nsec;

diff --git a/net/socket.c b/net/socket.c
index 6a9ab7a8b1d2..98f6544b0096 100644
--- a/net/socket.c
+++ b/net/socket.c

@@ -2833,7 +2833,7 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
 				    a[2], true);
 		break;
 	case SYS_RECVMMSG:
-		if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
+		if (IS_ENABLED(CONFIG_64BIT))
 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
 					     a[2], a[3],
 					     (struct __kernel_timespec __user *)a[4],

-- 
2.20.0

On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
[...]

[...]

It's not a problem with this patch, but I noticed that this condition
doesn't match what the comment says.  It looks like it was broken by:

commit 98f76206b33504b934209d16196477dfa519a807
Author: Dmitry Safonov [off-list ref]
Date:   Fri Oct 12 14:42:53 2018 +0100

    compat: Cleanup in_compat_syscall() callers

Ben.

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

On 11/20/19 10:28 PM, Ben Hutchings wrote:

On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
[...]

quoted

--- a/kernel/time/time.c
+++ b/kernel/time/time.c

@@ -267,7 +267,7 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
 }
 #endif
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
 {
 	struct __kernel_timex txc;		/* Local copy of parameter */

@@ -884,7 +884,7 @@ int get_timespec64(struct timespec64 *ts,
 	ts->tv_sec = kts.tv_sec;
 
 	/* Zero out the padding for 32 bit systems or in compat mode */
-	if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall())
+	if (in_compat_syscall())
 		kts.tv_nsec &= 0xFFFFFFFFUL;
 
 	ts->tv_nsec = kts.tv_nsec;

[...]

It's not a problem with this patch, but I noticed that this condition
doesn't match what the comment says.  It looks like it was broken by:

commit 98f76206b33504b934209d16196477dfa519a807
Author: Dmitry Safonov [off-list ref]
Date:   Fri Oct 12 14:42:53 2018 +0100

    compat: Cleanup in_compat_syscall() callers

Ugh, you right. I've failed to read the condition and thought it's
related to CONFIG_COMPAT :(
I'll send a fix shortly, thanks for spotting this!

-- 
          Dmitry

In order to remove the 'struct timespec' definition and the
timespec64_to_timespec() helper function, change over the in-kernel
definition of 'struct scm_timestamping' to use the __kernel_old_timespec
replacement and open-code the assignment.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/uapi/linux/errqueue.h | 7 +++++++
 net/core/scm.c                | 6 ++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h
index 28491dac074b..0cca19670fd2 100644
--- a/include/uapi/linux/errqueue.h
+++ b/include/uapi/linux/errqueue.h

@@ -37,9 +37,16 @@ struct sock_extended_err {
  *	The timestamping interfaces SO_TIMESTAMPING, MSG_TSTAMP_*
  *	communicate network timestamps by passing this struct in a cmsg with
  *	recvmsg(). See Documentation/networking/timestamping.txt for details.
+ *	User space sees a timespec definition that matches either
+ *	__kernel_timespec or __kernel_old_timespec, in the kernel we
+ *	require two structure definitions to provide both.
  */
 struct scm_timestamping {
+#ifdef __KERNEL__
+	struct __kernel_old_timespec ts[3];
+#else
 	struct timespec ts[3];
+#endif
 };
 
 struct scm_timestamping64 {

diff --git a/net/core/scm.c b/net/core/scm.c
index 31a38239c92f..dc6fed1f221c 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c

@@ -268,8 +268,10 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter
 	struct scm_timestamping tss;
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(tss.ts); i++)
-		tss.ts[i] = timespec64_to_timespec(tss_internal->ts[i]);
+	for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
+		tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
+		tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
+	}
 
 	put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss);
 }

-- 
2.20.0

Acked-by: Deepa Dinamani <redacted>

On Fri, Nov 8, 2019 at 10:15 PM Arnd Bergmann [off-list ref] wrote:

The kbuild bot pointed out that the way I sent this series, the use of
__kernel_old_timespec
causes a build failure, because I introduce this in a separate submission. I'm
moving this patch over to the other series, and changing the subject to

y2038: socket: use __kernel_old_timespec instead of timespec

With the expectation of merging it along with the other core patches.

      Arnd

On Fri, Nov 8, 2019 at 10:04 PM Arnd Bergmann [off-list ref] 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