[PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[Deepa Dinamani]

The series is a preparation series for individual architectures
to use 64 bit time_t syscalls in compat and 32 bit emulation modes.

This is a follow up to the series Arnd Bergmann posted:
https://sourceware.org/ml/libc-alpha/2015-05/msg00070.html [1]

Big picture is as per the lwn article:
https://lwn.net/Articles/643234/ [2]

The series is directed at converting posix clock syscalls:
clock_gettime, clock_settime, clock_getres and clock_nanosleep
to use a new data structure __kernel_timespec at syscall boundaries.
__kernel_timespec maintains 64 bit time_t across all execution modes.

vdso will be handled as part of each architecture when they enable
support for 64 bit time_t.

The compat syscalls are repurposed to provide backward compatibility
by using them as native syscalls as well for 32 bit architectures.
They will continue to use timespec at syscall boundaries.

CONFIG_64_BIT_TIME controls whether the syscalls use __kernel_timespec
or timespec at syscall boundaries.

The series does the following:
1. Enable compat syscalls on 32 bit architectures.
2. Add a new __kernel_timespec type to be used as the data structure
   for all the new syscalls.
3. Add new config CONFIG_64BIT_TIME(intead of the CONFIG_COMPAT_TIME in
   [1] and [2] to switch to new definition of __kernel_timespec. It is
   the same as struct timespec otherwise.
4. Add new CONFIG_32BIT_TIME to conditionally compile compat syscalls.

* Changes since v1:
 * Introduce CONFIG_32BIT_TIME
 * Fixed zeroing out of higher order bits of tv_nsec
 * Included Arnd's changes to fix up use of compat headers

I decided against using LEGACY_TIME_SYSCALLS to conditionally compile
legacy time syscalls such as sys_nanosleep because this will need to
enclose compat_sys_nanosleep as well. So, defining it as 

config LEGACY_TIME_SYSCALLS
     def_bool 64BIT || !64BIT_TIME

will not include compat_sys_nanosleep. We will instead need a new config to
exclusively mark legacy syscalls.

Deepa Dinamani (10):
  compat: Make compat helpers independent of CONFIG_COMPAT
  include: Move compat_timespec/ timeval to compat_time.h
  compat: enable compat_get/put_timespec64 always
  arch: introduce CONFIG_64BIT_TIME
  arch: Introduce CONFIG_COMPAT_32BIT_TIME
  posix-clocks: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME
  include: Add new y2038 safe __kernel_timespec
  fix get_timespec64() for y2038 safe compat interfaces
  change time types to new y2038 safe __kernel_* types
  nanosleep: change time types to safe __kernel_* types

 arch/Kconfig                           | 18 +++++++
 arch/arm64/include/asm/compat.h        | 11 ----
 arch/arm64/include/asm/stat.h          |  1 +
 arch/arm64/kernel/hw_breakpoint.c      |  1 -
 arch/arm64/kernel/perf_regs.c          |  2 +-
 arch/arm64/kernel/process.c            |  1 -
 arch/mips/include/asm/compat.h         | 11 ----
 arch/mips/kernel/signal32.c            |  2 +-
 arch/parisc/include/asm/compat.h       | 11 ----
 arch/powerpc/include/asm/compat.h      | 11 ----
 arch/powerpc/kernel/asm-offsets.c      |  2 +-
 arch/powerpc/oprofile/backtrace.c      |  2 +-
 arch/s390/hypfs/hypfs_sprp.c           |  1 -
 arch/s390/include/asm/compat.h         | 11 ----
 arch/s390/include/asm/elf.h            |  3 +-
 arch/s390/kvm/priv.c                   |  1 -
 arch/s390/pci/pci_clp.c                |  1 -
 arch/sparc/include/asm/compat.h        | 11 ----
 arch/tile/include/asm/compat.h         | 11 ----
 arch/x86/events/core.c                 |  2 +-
 arch/x86/include/asm/compat.h          | 11 ----
 arch/x86/include/asm/ftrace.h          |  2 +-
 arch/x86/include/asm/sys_ia32.h        |  2 +-
 arch/x86/kernel/sys_x86_64.c           |  2 +-
 drivers/s390/block/dasd_ioctl.c        |  1 -
 drivers/s390/char/fs3270.c             |  1 -
 drivers/s390/char/sclp_ctl.c           |  1 -
 drivers/s390/char/vmcp.c               |  1 -
 drivers/s390/cio/chsc_sch.c            |  1 -
 drivers/s390/net/qeth_core_main.c      |  2 +-
 drivers/staging/pi433/pi433_if.c       |  2 +-
 include/linux/compat.h                 | 11 ++--
 include/linux/compat_time.h            | 23 +++++++++
 include/linux/restart_block.h          |  7 +--
 include/linux/syscalls.h               | 12 ++---
 include/linux/time.h                   |  4 +-
 include/linux/time64.h                 | 10 +++-
 include/uapi/asm-generic/posix_types.h |  1 +
 include/uapi/linux/time.h              |  7 +++
 kernel/Makefile                        |  2 +-
 kernel/compat.c                        | 92 ++++++++++++++++++----------------
 kernel/time/hrtimer.c                  | 10 ++--
 kernel/time/posix-stubs.c              | 12 +++--
 kernel/time/posix-timers.c             | 24 ++++++---
 kernel/time/time.c                     | 10 +++-
 45 files changed, 175 insertions(+), 190 deletions(-)
 create mode 100644 include/linux/compat_time.h

base-commit: b0a84f19a5161418d4360cd57603e94ed489915e
-- 
2.14.1

Cc: acme@kernel.org
Cc: benh@kernel.crashing.org
Cc: borntraeger@de.ibm.com
Cc: catalin.marinas@arm.com
Cc: cmetcalf@mellanox.com
Cc: cohuck@redhat.com
Cc: davem@davemloft.net
Cc: deller@gmx.de
Cc: devel@driverdev.osuosl.org
Cc: gerald.schaefer@de.ibm.com
Cc: gregkh@linuxfoundation.org
Cc: heiko.carstens@de.ibm.com
Cc: hoeppner@linux.vnet.ibm.com
Cc: hpa@zytor.com
Cc: jejb@parisc-linux.org
Cc: jwi@linux.vnet.ibm.com
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: mark.rutland@arm.com
Cc: mingo@redhat.com
Cc: mpe@ellerman.id.au
Cc: oberpar@linux.vnet.ibm.com
Cc: oprofile-list@lists.sf.net
Cc: paulus@samba.org
Cc: peterz@infradead.org
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: rric@kernel.org
Cc: schwidefsky@de.ibm.com
Cc: sebott@linux.vnet.ibm.com
Cc: sparclinux@vger.kernel.org
Cc: sth@linux.vnet.ibm.com
Cc: ubraun@linux.vnet.ibm.com
Cc: will.deacon@arm.com
Cc: x86@kernel.org

[PATCH v2 02/10] include: Move compat_timespec/ timeval to compat_time.h

[Deepa Dinamani]

All the current architecture specific defines for these
are the same. Refactor these common defines to a common
header file.

The new common linux/compat_time.h is also useful as it
will eventually be used to hold all the defines that
are needed for compat time types that support non y2038
safe types. New architectures need not have to define these
new types as they will only use new y2038 safe syscalls.
This file can be deleted after y2038 when we stop supporting
non y2038 safe syscalls.

The patch also requires an operation similar to:

git grep "asm/compat\.h" | cut -d ":" -f 1 |  xargs -n 1 sed -i -e "s%asm/compat.h%linux/compat.h%g"

Cc: acme@kernel.org
Cc: benh@kernel.crashing.org
Cc: borntraeger@de.ibm.com
Cc: catalin.marinas@arm.com
Cc: cmetcalf@mellanox.com
Cc: cohuck@redhat.com
Cc: davem@davemloft.net
Cc: deller@gmx.de
Cc: devel@driverdev.osuosl.org
Cc: gerald.schaefer@de.ibm.com
Cc: gregkh@linuxfoundation.org
Cc: heiko.carstens@de.ibm.com
Cc: hoeppner@linux.vnet.ibm.com
Cc: hpa@zytor.com
Cc: jejb@parisc-linux.org
Cc: jwi@linux.vnet.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: mark.rutland@arm.com
Cc: mingo@redhat.com
Cc: mpe@ellerman.id.au
Cc: oberpar@linux.vnet.ibm.com
Cc: oprofile-list@lists.sf.net
Cc: paulus@samba.org
Cc: peterz@infradead.org
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: rric@kernel.org
Cc: schwidefsky@de.ibm.com
Cc: sebott@linux.vnet.ibm.com
Cc: sparclinux@vger.kernel.org
Cc: sth@linux.vnet.ibm.com
Cc: ubraun@linux.vnet.ibm.com
Cc: will.deacon@arm.com
Cc: x86@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/arm64/include/asm/compat.h   | 11 -----------
 arch/arm64/include/asm/stat.h     |  1 +
 arch/arm64/kernel/hw_breakpoint.c |  1 -
 arch/arm64/kernel/perf_regs.c     |  2 +-
 arch/arm64/kernel/process.c       |  1 -
 arch/mips/include/asm/compat.h    | 11 -----------
 arch/mips/kernel/signal32.c       |  2 +-
 arch/parisc/include/asm/compat.h  | 11 -----------
 arch/powerpc/include/asm/compat.h | 11 -----------
 arch/powerpc/kernel/asm-offsets.c |  2 +-
 arch/powerpc/oprofile/backtrace.c |  2 +-
 arch/s390/hypfs/hypfs_sprp.c      |  1 -
 arch/s390/include/asm/compat.h    | 11 -----------
 arch/s390/include/asm/elf.h       |  3 +--
 arch/s390/kvm/priv.c              |  1 -
 arch/s390/pci/pci_clp.c           |  1 -
 arch/sparc/include/asm/compat.h   | 11 -----------
 arch/tile/include/asm/compat.h    | 11 -----------
 arch/x86/events/core.c            |  2 +-
 arch/x86/include/asm/compat.h     | 11 -----------
 arch/x86/include/asm/ftrace.h     |  2 +-
 arch/x86/include/asm/sys_ia32.h   |  2 +-
 arch/x86/kernel/sys_x86_64.c      |  2 +-
 drivers/s390/block/dasd_ioctl.c   |  1 -
 drivers/s390/char/fs3270.c        |  1 -
 drivers/s390/char/sclp_ctl.c      |  1 -
 drivers/s390/char/vmcp.c          |  1 -
 drivers/s390/cio/chsc_sch.c       |  1 -
 drivers/s390/net/qeth_core_main.c |  2 +-
 drivers/staging/pi433/pi433_if.c  |  2 +-
 include/linux/compat.h            |  1 +
 include/linux/compat_time.h       | 19 +++++++++++++++++++
 32 files changed, 32 insertions(+), 110 deletions(-)
 create mode 100644 include/linux/compat_time.h

diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index a3c7f271ad4c..977b5064afc1 100644
--- a/arch/arm64/include/asm/compat.h
+++ b/arch/arm64/include/asm/compat.h
@@ -34,7 +34,6 @@
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef s32		compat_pid_t;
 typedef u16		__compat_uid_t;
@@ -66,16 +65,6 @@ typedef u32		compat_ulong_t;
 typedef u64		compat_u64;
 typedef u32		compat_uptr_t;
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 struct compat_stat {
 #ifdef __AARCH64EB__
 	short		st_dev;
diff --git a/arch/arm64/include/asm/stat.h b/arch/arm64/include/asm/stat.h
index 15e35598ac40..eab738019707 100644
--- a/arch/arm64/include/asm/stat.h
+++ b/arch/arm64/include/asm/stat.h
@@ -20,6 +20,7 @@
 
 #ifdef CONFIG_COMPAT
 
+#include <linux/compat_time.h>
 #include <asm/compat.h>
 
 /*
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index 749f81779420..bfa2b78cf0e3 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -29,7 +29,6 @@
 #include <linux/ptrace.h>
 #include <linux/smp.h>
 
-#include <asm/compat.h>
 #include <asm/current.h>
 #include <asm/debug-monitors.h>
 #include <asm/hw_breakpoint.h>
diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c
index 1d091d048d04..929fc369d0be 100644
--- a/arch/arm64/kernel/perf_regs.c
+++ b/arch/arm64/kernel/perf_regs.c
@@ -5,7 +5,7 @@
 #include <linux/bug.h>
 #include <linux/sched/task_stack.h>
 
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/perf_regs.h>
 #include <asm/ptrace.h>
 
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index b2adcce7bc18..1acb3097d35b 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -52,7 +52,6 @@
 #include <linux/thread_info.h>
 
 #include <asm/alternative.h>
-#include <asm/compat.h>
 #include <asm/cacheflush.h>
 #include <asm/exec.h>
 #include <asm/fpsimd.h>
diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index 49691331ada4..ccbf14e33282 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -14,7 +14,6 @@
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef s32		compat_suseconds_t;
 
@@ -46,16 +45,6 @@ typedef u32		compat_ulong_t;
 typedef u64		compat_u64;
 typedef u32		compat_uptr_t;
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 struct compat_stat {
 	compat_dev_t	st_dev;
 	s32		st_pad1[3];
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index cf5c7c05e5a3..a6b04c70a8cb 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -14,7 +14,7 @@
 #include <linux/signal.h>
 #include <linux/syscalls.h>
 
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/compat-signal.h>
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index acf8aa07cbe0..90f844b16beb 100644
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -13,7 +13,6 @@
 
 typedef u32	compat_size_t;
 typedef s32	compat_ssize_t;
-typedef s32	compat_time_t;
 typedef s32	compat_clock_t;
 typedef s32	compat_pid_t;
 typedef u32	__compat_uid_t;
@@ -40,16 +39,6 @@ typedef u32	compat_ulong_t;
 typedef u64	compat_u64;
 typedef u32	compat_uptr_t;
 
-struct compat_timespec {
-	compat_time_t		tv_sec;
-	s32			tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t		tv_sec;
-	s32			tv_usec;
-};
-
 struct compat_stat {
 	compat_dev_t		st_dev;	/* dev_t is 32 bits on parisc */
 	compat_ino_t		st_ino;	/* 32 bits */
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index 8a2aecfe9b02..517dbcfc2240 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -17,7 +17,6 @@
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef s32		compat_pid_t;
 typedef u32		__compat_uid_t;
@@ -45,16 +44,6 @@ typedef u32		compat_ulong_t;
 typedef u64		compat_u64;
 typedef u32		compat_uptr_t;
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 struct compat_stat {
 	compat_dev_t	st_dev;
 	compat_ino_t	st_ino;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 6b958414b4e0..a25cbe6482e2 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -42,7 +42,7 @@
 #include <asm/paca.h>
 #include <asm/lppaca.h>
 #include <asm/cache.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/mmu.h>
 #include <asm/hvcall.h>
 #include <asm/xics.h>
diff --git a/arch/powerpc/oprofile/backtrace.c b/arch/powerpc/oprofile/backtrace.c
index ecc66d5f02c9..11ff763c03ad 100644
--- a/arch/powerpc/oprofile/backtrace.c
+++ b/arch/powerpc/oprofile/backtrace.c
@@ -11,7 +11,7 @@
 #include <linux/sched.h>
 #include <asm/processor.h>
 #include <linux/uaccess.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/oprofile_impl.h>
 
 #define STACK_SP(STACK)		*(STACK)
diff --git a/arch/s390/hypfs/hypfs_sprp.c b/arch/s390/hypfs/hypfs_sprp.c
index ae0ed8dd5f1b..5d85a039391c 100644
--- a/arch/s390/hypfs/hypfs_sprp.c
+++ b/arch/s390/hypfs/hypfs_sprp.c
@@ -13,7 +13,6 @@
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>
-#include <asm/compat.h>
 #include <asm/diag.h>
 #include <asm/sclp.h>
 #include "hypfs.h"
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 5e6a63641a5f..7e587eb9fb58 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -53,7 +53,6 @@
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef s32		compat_pid_t;
 typedef u16		__compat_uid_t;
@@ -97,16 +96,6 @@ typedef struct {
 	u32 gprs_high[NUM_GPRS];
 } s390_compat_regs_high;
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 struct compat_stat {
 	compat_dev_t	st_dev;
 	u16		__pad1;
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index 1a61b1b997f2..3e15c77c7c9a 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -126,7 +126,7 @@
  */
 
 #include <asm/ptrace.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/syscall.h>
 #include <asm/user.h>
 
@@ -136,7 +136,6 @@ typedef s390_regs elf_gregset_t;
 typedef s390_fp_regs compat_elf_fpregset_t;
 typedef s390_compat_regs compat_elf_gregset_t;
 
-#include <linux/compat.h>
 #include <linux/sched/mm.h>	/* for task_struct */
 #include <asm/mmu_context.h>
 
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index c954ac49eee4..07eebba4bd37 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -29,7 +29,6 @@
 #include <asm/gmap.h>
 #include <asm/io.h>
 #include <asm/ptrace.h>
-#include <asm/compat.h>
 #include <asm/sclp.h>
 #include "gaccess.h"
 #include "kvm-s390.h"
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 93cd0f1ca12b..19b2d2a9b43d 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -19,7 +19,6 @@
 #include <linux/uaccess.h>
 #include <asm/pci_debug.h>
 #include <asm/pci_clp.h>
-#include <asm/compat.h>
 #include <asm/clp.h>
 #include <uapi/asm/clp.h>
 
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index fa38c78de0f0..5b49b6a66cdb 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -11,7 +11,6 @@
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef s32		compat_pid_t;
 typedef u16		__compat_uid_t;
@@ -39,16 +38,6 @@ typedef u32		compat_ulong_t;
 typedef u64		compat_u64;
 typedef u32		compat_uptr_t;
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 struct compat_stat {
 	compat_dev_t	st_dev;
 	compat_ino_t	st_ino;
diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h
index 62a7b83025dd..21ab5b80f5c7 100644
--- a/arch/tile/include/asm/compat.h
+++ b/arch/tile/include/asm/compat.h
@@ -29,7 +29,6 @@ typedef u32		compat_ulong_t;
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
 typedef s32		compat_off_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef u32		compat_ino_t;
 typedef u32		compat_caddr_t;
@@ -59,16 +58,6 @@ typedef unsigned long compat_elf_greg_t;
 #define COMPAT_ELF_NGREG (sizeof(struct pt_regs) / sizeof(compat_elf_greg_t))
 typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG];
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 #define compat_stat stat
 #define compat_statfs statfs
 
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 140d33288e78..6b8961912781 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2391,7 +2391,7 @@ static unsigned long get_segment_base(unsigned int segment)
 
 #ifdef CONFIG_IA32_EMULATION
 
-#include <asm/compat.h>
+#include <linux/compat.h>
 
 static inline int
 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 2cbd75dd2fd3..160804ed875e 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -17,7 +17,6 @@
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
-typedef s32		compat_time_t;
 typedef s32		compat_clock_t;
 typedef s32		compat_pid_t;
 typedef u16		__compat_uid_t;
@@ -46,16 +45,6 @@ typedef u32		compat_u32;
 typedef u64 __attribute__((aligned(4))) compat_u64;
 typedef u32		compat_uptr_t;
 
-struct compat_timespec {
-	compat_time_t	tv_sec;
-	s32		tv_nsec;
-};
-
-struct compat_timeval {
-	compat_time_t	tv_sec;
-	s32		tv_usec;
-};
-
 struct compat_stat {
 	compat_dev_t	st_dev;
 	u16		__pad1;
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 09ad88572746..db25aa15b705 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -49,7 +49,7 @@ int ftrace_int3_handler(struct pt_regs *regs);
 #if !defined(__ASSEMBLY__) && !defined(COMPILE_OFFSETS)
 
 #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION)
-#include <asm/compat.h>
+#include <linux/compat.h>
 
 /*
  * Because ia32 syscalls do not map to x86_64 syscall numbers
diff --git a/arch/x86/include/asm/sys_ia32.h b/arch/x86/include/asm/sys_ia32.h
index 82c34ee25a65..8527b26ad36f 100644
--- a/arch/x86/include/asm/sys_ia32.h
+++ b/arch/x86/include/asm/sys_ia32.h
@@ -16,7 +16,7 @@
 #include <linux/linkage.h>
 #include <linux/types.h>
 #include <linux/signal.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/ia32.h>
 
 /* ia32/sys_ia32.c */
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 676774b9bb8d..9d8ea652e31c 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -19,7 +19,7 @@
 #include <linux/elf.h>
 
 #include <asm/elf.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/ia32.h>
 #include <asm/syscalls.h>
 #include <asm/mpx.h>
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 7bdc6aaa0ba3..2016e0ed5865 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -18,7 +18,6 @@
 #include <linux/fs.h>
 #include <linux/blkpg.h>
 #include <linux/slab.h>
-#include <asm/compat.h>
 #include <asm/ccwdev.h>
 #include <asm/schid.h>
 #include <asm/cmb.h>
diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 61822480a2a0..16a4e8528bbc 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -19,7 +19,6 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 
-#include <asm/compat.h>
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
 #include <asm/ebcdic.h>
diff --git a/drivers/s390/char/sclp_ctl.c b/drivers/s390/char/sclp_ctl.c
index a78cea0c3a09..248b5db3eaa8 100644
--- a/drivers/s390/char/sclp_ctl.c
+++ b/drivers/s390/char/sclp_ctl.c
@@ -14,7 +14,6 @@
 #include <linux/init.h>
 #include <linux/ioctl.h>
 #include <linux/fs.h>
-#include <asm/compat.h>
 #include <asm/sclp_ctl.h>
 #include <asm/sclp.h>
 
diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c
index 17e411c57576..948ce82a7725 100644
--- a/drivers/s390/char/vmcp.c
+++ b/drivers/s390/char/vmcp.c
@@ -23,7 +23,6 @@
 #include <linux/mutex.h>
 #include <linux/cma.h>
 #include <linux/mm.h>
-#include <asm/compat.h>
 #include <asm/cpcmd.h>
 #include <asm/debug.h>
 #include <asm/vmcp.h>
diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index 0015729d917d..8d9f36625ba5 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -16,7 +16,6 @@
 #include <linux/miscdevice.h>
 #include <linux/kernel_stat.h>
 
-#include <asm/compat.h>
 #include <asm/cio.h>
 #include <asm/chsc.h>
 #include <asm/isc.h>
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 98a7f84540ab..a93591c6c9b0 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -27,7 +27,7 @@
 #include <asm/chpid.h>
 #include <asm/io.h>
 #include <asm/sysinfo.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/diag.h>
 #include <asm/cio.h>
 #include <asm/ccwdev.h>
diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
index 2a205c6173dc..473831ff8745 100644
--- a/drivers/staging/pi433/pi433_if.c
+++ b/drivers/staging/pi433/pi433_if.c
@@ -48,7 +48,7 @@
 #include <linux/wait.h>
 #include <linux/spi/spi.h>
 #ifdef CONFIG_COMPAT
-#include <asm/compat.h>
+#include <linux/compat.h>
 #endif
 
 #include "pi433_if.h"
diff --git a/include/linux/compat.h b/include/linux/compat.h
index b24aaf66feb4..2f79dac5ed65 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -7,6 +7,7 @@
  */
 
 #include <linux/types.h>
+#include <linux/compat_time.h>
 
 #include <linux/stat.h>
 #include <linux/param.h>	/* for HZ */
diff --git a/include/linux/compat_time.h b/include/linux/compat_time.h
new file mode 100644
index 000000000000..56a54a1e4355
--- /dev/null
+++ b/include/linux/compat_time.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_COMPAT_TIME_H
+#define _LINUX_COMPAT_TIME_H
+
+#include <linux/types.h>
+
+typedef s32		compat_time_t;
+
+struct compat_timespec {
+	compat_time_t	tv_sec;
+	s32		tv_nsec;
+};
+
+struct compat_timeval {
+	compat_time_t	tv_sec;
+	s32		tv_usec;
+};
+
+#endif /* _LINUX_COMPAT_TIME_H */
-- 
2.14.1

Re: [PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[Arnd Bergmann]

On Mon, Nov 27, 2017 at 8:30 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> The series is a preparation series for individual architectures
> to use 64 bit time_t syscalls in compat and 32 bit emulation modes.
>
> This is a follow up to the series Arnd Bergmann posted:
> https://sourceware.org/ml/libc-alpha/2015-05/msg00070.html [1]
>
> Big picture is as per the lwn article:
> https://lwn.net/Articles/643234/ [2]
>
> The series is directed at converting posix clock syscalls:
> clock_gettime, clock_settime, clock_getres and clock_nanosleep
> to use a new data structure __kernel_timespec at syscall boundaries.
> __kernel_timespec maintains 64 bit time_t across all execution modes.
>
> vdso will be handled as part of each architecture when they enable
> support for 64 bit time_t.
>
> The compat syscalls are repurposed to provide backward compatibility
> by using them as native syscalls as well for 32 bit architectures.
> They will continue to use timespec at syscall boundaries.
>
> CONFIG_64_BIT_TIME controls whether the syscalls use __kernel_timespec
> or timespec at syscall boundaries.
>
> The series does the following:
> 1. Enable compat syscalls on 32 bit architectures.
> 2. Add a new __kernel_timespec type to be used as the data structure
>    for all the new syscalls.
> 3. Add new config CONFIG_64BIT_TIME(intead of the CONFIG_COMPAT_TIME in
>    [1] and [2] to switch to new definition of __kernel_timespec. It is
>    the same as struct timespec otherwise.
> 4. Add new CONFIG_32BIT_TIME to conditionally compile compat syscalls.
>
> * Changes since v1:
>  * Introduce CONFIG_32BIT_TIME
>  * Fixed zeroing out of higher order bits of tv_nsec
>  * Included Arnd's changes to fix up use of compat headers

Very nice. I think it would be good to get this into linux-next soon so we
can build on top of this. I have submitted most other y2038 patches today
that don't depend on either this or one of my other patches.

There is one patch that I want to do but haven't imlpemented yet, to merge
get_timespec64() and compat_get_timespec() into one function that
take a bunch of flags (check nanosecond, nano/microsecond,
zero upper half of nanoseconds, 32-bit or 64-bit wide), since I found
a few functions that need more than one of these, and they don't
all need the same combinations. My patch will certainly conflict
with yours, as your touch the same functions, but that's fine.

If you end up doing another version of the series though, it might
be better to move the compat accessors into kernel/time/time.c
along with the native functions, that should make it easier to
consolidate them later.

> I decided against using LEGACY_TIME_SYSCALLS to conditionally compile
> legacy time syscalls such as sys_nanosleep because this will need to
> enclose compat_sys_nanosleep as well. So, defining it as
>
> config LEGACY_TIME_SYSCALLS
>      def_bool 64BIT || !64BIT_TIME
>
> will not include compat_sys_nanosleep. We will instead need a new config to
> exclusively mark legacy syscalls.

Do you mean we would need to do this separately for native and compat
syscalls, and have yet another option, like LEGACY_TIME_SYSCALLS
and LEGACY_TIME_COMPAT_SYSCALLS, to cover all cases? I would
think that CONFIG_COMPAT_32BIT_TIME handles all the compat versions,
while CONFIG_LEGACY_TIME_SYSCALLS handles all the native ones.

       Arnd

Re: [PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[Deepa Dinamani]

>> I decided against using LEGACY_TIME_SYSCALLS to conditionally compile
>> legacy time syscalls such as sys_nanosleep because this will need to
>> enclose compat_sys_nanosleep as well. So, defining it as
>>
>> config LEGACY_TIME_SYSCALLS
>>      def_bool 64BIT || !64BIT_TIME
>>
>> will not include compat_sys_nanosleep. We will instead need a new config to
>> exclusively mark legacy syscalls.
>
> Do you mean we would need to do this separately for native and compat
> syscalls, and have yet another option, like LEGACY_TIME_SYSCALLS
> and LEGACY_TIME_COMPAT_SYSCALLS, to cover all cases? I would
> think that CONFIG_COMPAT_32BIT_TIME handles all the compat versions,
> while CONFIG_LEGACY_TIME_SYSCALLS handles all the native ones.

I meant sys_nanosleep would be covered by LEGACY_TIME_SYSCALLS, but
compat_sys_nanosleep would be covered by CONFIG_COMPAT_32BIT_TIME
along with other compat syscalls.
So, if we define the LEGACY_TIME_SYSCALLS as


        "This controls the compilation of the following system calls:
        time, stime, gettimeofday, settimeofday, adjtimex, nanosleep,
alarm, getitimer,
        setitimer, select, utime, utimes, futimesat, and
{old,new}{l,f,}stat{,64}.
        These all pass 32-bit time_t arguments on 32-bit architectures and
        are replaced by other interfaces (e.g. posix timers and clocks, statx).
        C libraries implementing 64-bit time_t in 32-bit architectures have to
        implement the handles by wrapping around the newer interfaces.
        New architectures should not explicitly enable this."

This would not be really true as compat interfaces have nothing to do
with this config.

I was proposing that we could have LEGACY_TIME_SYSCALLS config, but
then have all these "deprecated" syscalls be enclosed within this,
compat or not.
This will also mean that we will have to come up representing these
syscalls in the syscall header files.
This can be a separate patch and this series can be merged as is if
everyone agrees.

-Deepa

Re: [PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[Arnd Bergmann]

On Mon, Nov 27, 2017 at 11:29 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
>>> I decided against using LEGACY_TIME_SYSCALLS to conditionally compile
>>> legacy time syscalls such as sys_nanosleep because this will need to
>>> enclose compat_sys_nanosleep as well. So, defining it as
>>>
>>> config LEGACY_TIME_SYSCALLS
>>>      def_bool 64BIT || !64BIT_TIME
>>>
>>> will not include compat_sys_nanosleep. We will instead need a new config to
>>> exclusively mark legacy syscalls.
>>
>> Do you mean we would need to do this separately for native and compat
>> syscalls, and have yet another option, like LEGACY_TIME_SYSCALLS
>> and LEGACY_TIME_COMPAT_SYSCALLS, to cover all cases? I would
>> think that CONFIG_COMPAT_32BIT_TIME handles all the compat versions,
>> while CONFIG_LEGACY_TIME_SYSCALLS handles all the native ones.
>
> I meant sys_nanosleep would be covered by LEGACY_TIME_SYSCALLS, but
> compat_sys_nanosleep would be covered by CONFIG_COMPAT_32BIT_TIME
> along with other compat syscalls.
> So, if we define the LEGACY_TIME_SYSCALLS as
>
>
>         "This controls the compilation of the following system calls:
>         time, stime, gettimeofday, settimeofday, adjtimex, nanosleep,
> alarm, getitimer,
>         setitimer, select, utime, utimes, futimesat, and
> {old,new}{l,f,}stat{,64}.
>         These all pass 32-bit time_t arguments on 32-bit architectures and
>         are replaced by other interfaces (e.g. posix timers and clocks, statx).
>         C libraries implementing 64-bit time_t in 32-bit architectures have to
>         implement the handles by wrapping around the newer interfaces.
>         New architectures should not explicitly enable this."
>
> This would not be really true as compat interfaces have nothing to do
> with this config.
>
> I was proposing that we could have LEGACY_TIME_SYSCALLS config, but
> then have all these "deprecated" syscalls be enclosed within this,
> compat or not.
> This will also mean that we will have to come up representing these
> syscalls in the syscall header files.
> This can be a separate patch and this series can be merged as is if
> everyone agrees.

I think doing this separately  would be good, I don't see any interdependency
with the other patches, we just need to decide what we want in the long
run.

I agree my text that you cited doesn't capture the situation correctly,
as this is really about the obsolete system calls that take 64-bit time_t
arguments on architectures that are converted to allow 64-bit time_t
for non-obsolete system calls.

Maybe it's better to just reword this to

      "This controls the compilation of the following system calls:
      time, stime, gettimeofday, settimeofday, adjtimex, nanosleep,
alarm, getitimer,
      setitimer, select, utime, utimes, futimesat, and {old,new}{l,f,}stat{,64}.
      These are all replaced by other interfaces (e.g. posix timers and clocks,
      statx) on architectures that got converted from 32-bit time_t to
64-bit time_t.
      C libraries implementing 64-bit time_t in 32-bit architectures have to
      implement the handles by wrapping around the newer interfaces.
      New architectures should not explicitly enable this."

That would clarify that it's not about the compat system calls, while
also allowing the two options to be set independently.

        Arnd

Re: [PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[Deepa Dinamani]

On Tue, Nov 28, 2017 at 6:17 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Mon, Nov 27, 2017 at 11:29 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
>>>> I decided against using LEGACY_TIME_SYSCALLS to conditionally compile
>>>> legacy time syscalls such as sys_nanosleep because this will need to
>>>> enclose compat_sys_nanosleep as well. So, defining it as
>>>>
>>>> config LEGACY_TIME_SYSCALLS
>>>>      def_bool 64BIT || !64BIT_TIME
>>>>
>>>> will not include compat_sys_nanosleep. We will instead need a new config to
>>>> exclusively mark legacy syscalls.
>>>
>>> Do you mean we would need to do this separately for native and compat
>>> syscalls, and have yet another option, like LEGACY_TIME_SYSCALLS
>>> and LEGACY_TIME_COMPAT_SYSCALLS, to cover all cases? I would
>>> think that CONFIG_COMPAT_32BIT_TIME handles all the compat versions,
>>> while CONFIG_LEGACY_TIME_SYSCALLS handles all the native ones.
>>
>> I meant sys_nanosleep would be covered by LEGACY_TIME_SYSCALLS, but
>> compat_sys_nanosleep would be covered by CONFIG_COMPAT_32BIT_TIME
>> along with other compat syscalls.
>> So, if we define the LEGACY_TIME_SYSCALLS as
>>
>>
>>         "This controls the compilation of the following system calls:
>>         time, stime, gettimeofday, settimeofday, adjtimex, nanosleep,
>> alarm, getitimer,
>>         setitimer, select, utime, utimes, futimesat, and
>> {old,new}{l,f,}stat{,64}.
>>         These all pass 32-bit time_t arguments on 32-bit architectures and
>>         are replaced by other interfaces (e.g. posix timers and clocks, statx).
>>         C libraries implementing 64-bit time_t in 32-bit architectures have to
>>         implement the handles by wrapping around the newer interfaces.
>>         New architectures should not explicitly enable this."
>>
>> This would not be really true as compat interfaces have nothing to do
>> with this config.
>>
>> I was proposing that we could have LEGACY_TIME_SYSCALLS config, but
>> then have all these "deprecated" syscalls be enclosed within this,
>> compat or not.
>> This will also mean that we will have to come up representing these
>> syscalls in the syscall header files.
>> This can be a separate patch and this series can be merged as is if
>> everyone agrees.
>
> I think doing this separately  would be good, I don't see any interdependency
> with the other patches, we just need to decide what we want in the long
> run.

Right. There are three options:

1. Use two configs to identify which syscalls need not be supported by
new architectures.
In this case it makes sense to say LEGACY_TIME_SYSCALLS and
COMPAT_32BIT_TIME both need to be disabled for new architectures. And,
I can reword the config to what you mention below.

2. Make the LEGACY_TIME_SYSCALLS eliminate non y2038 safe syscalls
mentioned below only.
In this case only the native and compat functions of the below
mentioned syscalls need to be identified by the config. I like this
option as this clearly identifies which syscalls are deprecated and do
not have a 64 bit counterpart. Not all architectures need to support
turning this off.

3. If we don't need either 1 or 2, then we could stick with what we
have today in the series as CONFIG_64BIT_TIME will be deleted and they
only need #ifdef CONFIG_64BIT.

Let me know if anyone prefers something else.

> I agree my text that you cited doesn't capture the situation correctly,
> as this is really about the obsolete system calls that take 64-bit time_t
> arguments on architectures that are converted to allow 64-bit time_t
> for non-obsolete system calls.
>
> Maybe it's better to just reword this to
>
>       "This controls the compilation of the following system calls:
>       time, stime, gettimeofday, settimeofday, adjtimex, nanosleep,
> alarm, getitimer,
>       setitimer, select, utime, utimes, futimesat, and {old,new}{l,f,}stat{,64}.
>       These are all replaced by other interfaces (e.g. posix timers and clocks,
>       statx) on architectures that got converted from 32-bit time_t to
> 64-bit time_t.
>       C libraries implementing 64-bit time_t in 32-bit architectures have to
>       implement the handles by wrapping around the newer interfaces.
>       New architectures should not explicitly enable this."
>
> That would clarify that it's not about the compat system calls, while
> also allowing the two options to be set independently.

-Deepa

Re: [PATCH v2 00/10] posix_clocks: Prepare syscalls for 64 bit time_t conversion

[Arnd Bergmann]

On Wed, Nov 29, 2017 at 12:17 AM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> On Tue, Nov 28, 2017 at 6:17 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>> On Mon, Nov 27, 2017 at 11:29 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> Right. There are three options:
>
> 1. Use two configs to identify which syscalls need not be supported by
> new architectures.
> In this case it makes sense to say LEGACY_TIME_SYSCALLS and
> COMPAT_32BIT_TIME both need to be disabled for new architectures. And,
> I can reword the config to what you mention below.
>
> 2. Make the LEGACY_TIME_SYSCALLS eliminate non y2038 safe syscalls
> mentioned below only.
> In this case only the native and compat functions of the below
> mentioned syscalls need to be identified by the config. I like this
> option as this clearly identifies which syscalls are deprecated and do
> not have a 64 bit counterpart. Not all architectures need to support
> turning this off.
>
> 3. If we don't need either 1 or 2, then we could stick with what we
> have today in the series as CONFIG_64BIT_TIME will be deleted and they
> only need #ifdef CONFIG_64BIT.
>
> Let me know if anyone prefers something else.

I think I prefer to have both LEGACY_TIME_SYSCALLS to guard
the native deprecated syscalls (disabled on 32-bit architectures after
the conversion, and enabled on 64-bit architectures until
we merge the next one), and COMPAT_32BIT_TIME to guard the
compat versions of both the deprecated and the non-deprecated
syscalls (enabled on all existing 32-bit architectures after the
conversion, and on 64-bit architectures if they provide a compat
mode for the former).

Those two are not symmetric, but I think those are the most
common combinations, and the Kconfig symbol helps document
what they are.

There is one more category for things like io_getevents() and
rt_sigtimedwait that also need two separate compat versions,
one for 32-bit time_t and one for 64-bit time_t, but it seems better
to deal with those case-by-case rather than introducing another
Kconfig symbol.

        Arnd