[GIT PULL, PATCH v4 00/16] y2038: IPC system call conversion

From: Arnd Bergmann
Date: Wed Apr 25 2018 - 09:25:01 EST

Hi Thomas,

This is a small update to last week's patch series, I hope I
have worked out all the remaining issues now. If nothing else
comes up, please pull into tip for 4.18. The commits are
based on top of what you already pulled into timers/core, so
you can either add these to the same branch or to a different

I'll be away for three weeks starting on Sunday, so if new
issues get found, I won't be able to address them until I get
back home. I'll post another set of simpler syscall patches for
review after this, and there is at last a fourth set of those
that are not ready yet, but is available for preview at [3],
which also contains unrelated y2038 patches for random


The following changes since commit 01909974b41036a6a8d3907c66cc7b41c9a73da9:

time: Change nanosleep to safe __kernel_* types (2018-04-19 13:32:03 +0200)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git y2038-ipc

for you to fetch changes up to 5dc0b1529d21b54aad4098874e334a52027fd16d:

y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop (2018-04-20 16:20:30 +0200)

y2038: IPC system call conversion

This is a follow-up to Deepa's work on the timekeeping system calls,
providing a y2038-safe syscall API for SYSVIPC. It uses a combination
of two strategies:

For sys_msgctl, sys_semctl and sys_shmctl, I do not introduce a completely
new set of replacement system calls, but instead extend the existing
ones to return data in the reserved fields of the normal data structure.

This should be completely transparent to any existing user space, and
only after the 32-bit time_t wraps, it will make a difference in the
returned data.

libc implementations will consequently have to provide their own data
structures when they move to 64-bit time_t, and convert the structures
in user space from the ones returned by the kernel.

In contrast, mq_timedsend, mq_timedreceive and and semtimedop all do
need to change because having a libc redefine the timespec type
breaks the ABI, so with this series there will be two separate entry
points for 32-bit architectures.

There are three cases here:

- little-endian architectures (except powerpc and mips) can use
the normal layout and just cast the data structure to the user space
type that contains 64-bit numbers.

- parisc and sparc can do the same thing with big-endian user space

- little-endian powerpc and most big-endian architectures have
to flip the upper and lower 32-bit halves of the time_t value in memory,
but can otherwise keep using the normal layout

- mips and big-endian xtensa need to be more careful because
they are not consistent in their definitions, and they have to provide
custom libc implementations for the system calls to use 64-bit time_t.

Changes to v3:
- reworked x86 portion after discovering an old bug, submitted
a fix for that separately.
- use consistent types in asm-generic based on feedback from
Jeffrey Walton

Changes to v2:
- added patches for mq_timedsend, mq_timedreceive and and semtimedop
system calls
- add asm-generic/compat.h changes to prepare for actually using those
on 32-bit.
- fix 'make headers_install' as reported by Heiko Carstens
- fix MIPS build as reported by build bot
- Cc everyone on all patches as originally intended, not just on the
cover letter.

Changes to v1 [1]:
- Rebased to the latest kernel (4.17-rc)
- Dropped changes for removed architectures
- Simplified the IPC code changes, based on prior work from
both Deepa and Eric
- Fixed a few bugs that I found during rebasing, in parcular the
sparc version was incorrect.

[1] https://lkml.org/lkml/2015/5/20/605
[2] https://lwn.net/Articles/751676/
[3] git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git y2038-next


Arnd Bergmann (16):
y2038: asm-generic: Extend sysvipc data structures
y2038: x86: Extend sysvipc data structures
y2038: alpha: Remove unneeded ipc uapi header files
y2038: ia64: Remove unneeded ipc uapi header files
y2038: s390: Remove unneeded ipc uapi header files
y2038: arm64: Extend sysvipc compat data structures
y2038: mips: Extend sysvipc data structures
y2038: parisc: Extend sysvipc data structures
y2038: sparc: Extend sysvipc data structures
y2038: powerpc: Extend sysvipc data structures
y2038: xtensa: Extend sysvipc data structures
y2038: ipc: Use ktime_get_real_seconds consistently
y2038: ipc: Report long times to user space
y2038: ipc: Use __kernel_timespec
y2038: ipc: Enable COMPAT_32BIT_TIME
y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop

Cc: linux-api@xxxxxxxxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: libc-alpha@xxxxxxxxxxxxxx
Cc: tglx@xxxxxxxxxxxxx
Cc: deepa.kernel@xxxxxxxxx
Cc: viro@xxxxxxxxxxxxxxxxxx
Cc: ebiederm@xxxxxxxxxxxx
Cc: albert.aribaud@xxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: schwidefsky@xxxxxxxxxx
Cc: x86@xxxxxxxxxx
Cc: catalin.marinas@xxxxxxx
Cc: will.deacon@xxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: jhogan@xxxxxxxxxx
Cc: ralf@xxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: sparclinux@xxxxxxxxxxxxxxx
Cc: Zack Weinberg <zackw@xxxxxxxxx>
Cc: Jeffrey Walton <noloader@xxxxxxxxx>

arch/alpha/include/uapi/asm/Kbuild | 4 ++
arch/alpha/include/uapi/asm/ipcbuf.h | 2 -
arch/alpha/include/uapi/asm/msgbuf.h | 28 -----------
arch/alpha/include/uapi/asm/sembuf.h | 23 ---------
arch/alpha/include/uapi/asm/shmbuf.h | 39 ---------------
arch/arm64/include/asm/compat.h | 32 ++++++-------
arch/ia64/include/uapi/asm/Kbuild | 4 ++
arch/ia64/include/uapi/asm/ipcbuf.h | 2 -
arch/ia64/include/uapi/asm/msgbuf.h | 28 -----------
arch/ia64/include/uapi/asm/sembuf.h | 23 ---------
arch/ia64/include/uapi/asm/shmbuf.h | 39 ---------------
arch/mips/include/asm/compat.h | 40 +++++++++-------
arch/mips/include/uapi/asm/msgbuf.h | 57 ++++++++++++++--------
arch/mips/include/uapi/asm/sembuf.h | 15 +++++-
arch/mips/include/uapi/asm/shmbuf.h | 23 ++++++++-
arch/parisc/include/asm/compat.h | 32 ++++++-------
arch/parisc/include/uapi/asm/msgbuf.h | 33 +++++++------
arch/parisc/include/uapi/asm/sembuf.h | 16 +++----
arch/parisc/include/uapi/asm/shmbuf.h | 19 ++++----
arch/powerpc/include/asm/compat.h | 32 ++++++-------
arch/powerpc/include/uapi/asm/msgbuf.h | 18 +++----
arch/powerpc/include/uapi/asm/sembuf.h | 14 +++---
arch/powerpc/include/uapi/asm/shmbuf.h | 19 ++++----
arch/s390/include/asm/compat.h | 32 ++++++-------
arch/s390/include/uapi/asm/Kbuild | 3 ++
arch/s390/include/uapi/asm/msgbuf.h | 38 ---------------
arch/s390/include/uapi/asm/sembuf.h | 30 ------------
arch/s390/include/uapi/asm/shmbuf.h | 49 -------------------
arch/sparc/include/asm/compat.h | 32 ++++++-------
arch/sparc/include/uapi/asm/msgbuf.h | 22 ++++-----
arch/sparc/include/uapi/asm/sembuf.h | 16 +++----
arch/sparc/include/uapi/asm/shmbuf.h | 21 ++++-----
arch/x86/include/asm/compat.h | 32 ++++++-------
arch/x86/include/uapi/asm/sembuf.h | 11 ++++-
arch/xtensa/include/uapi/asm/msgbuf.h | 25 +++++-----
arch/xtensa/include/uapi/asm/sembuf.h | 17 ++++---
arch/xtensa/include/uapi/asm/shmbuf.h | 37 ++++-----------
include/linux/syscalls.h | 6 +--
include/uapi/asm-generic/msgbuf.h | 27 +++++------
include/uapi/asm-generic/sembuf.h | 26 ++++++----
include/uapi/asm-generic/shmbuf.h | 41 ++++++++--------
ipc/mqueue.c | 86 +++++++++++++++++-----------------
ipc/msg.c | 20 +++++---
ipc/sem.c | 27 +++++++----
ipc/shm.c | 14 ++++--
ipc/syscall.c | 13 +++--
ipc/util.h | 4 +-
47 files changed, 471 insertions(+), 700 deletions(-)
elete mode 100644 arch/alpha/include/uapi/asm/ipcbuf.h
delete mode 100644 arch/alpha/include/uapi/asm/msgbuf.h
delete mode 100644 arch/alpha/include/uapi/asm/sembuf.h
delete mode 100644 arch/alpha/include/uapi/asm/shmbuf.h
delete mode 100644 arch/ia64/include/uapi/asm/ipcbuf.h
delete mode 100644 arch/ia64/include/uapi/asm/msgbuf.h
delete mode 100644 arch/ia64/include/uapi/asm/sembuf.h
delete mode 100644 arch/ia64/include/uapi/asm/shmbuf.h
delete mode 100644 arch/s390/include/uapi/asm/msgbuf.h
delete mode 100644 arch/s390/include/uapi/asm/sembuf.h
delete mode 100644 arch/s390/include/uapi/asm/shmbuf.h