Merge tag 'y2038-timekeeping' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground into timers/core

Pull y2038 timekeeping syscall changes from Arnd Bergmann:

This is the first set of system call entry point changes to enable 32-bit
architectures to have variants on both 32-bit and 64-bit time_t. Typically
these system calls take a 'struct timespec' argument, but that structure
is defined in user space by the C library and its layout will change.

The kernel already supports handling the 32-bit time_t on 64-bit
architectures through the CONFIG_COMPAT mechanism. As there are a total
of 51 system calls suffering from this problem, reusing that mechanism
on 32-bit architectures.

We already have patches for most of the remaining system calls, but this
set contains most of the complexity and is best tested.  There was one
last-minute regression that prevented it from going into 4.17, but that
is fixed now.

More details from Deepa's patch series description:

   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.

57 files changed, 201 insertions, 176 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 8e0d665c8d53..4377b0cec976 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -870,6 +870,21 @@ config OLD_SIGACTION
 config COMPAT_OLD_SIGACTION
 	bool
 
+config 64BIT_TIME
+	def_bool ARCH_HAS_64BIT_TIME
+	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 && 64BIT_TIME) || COMPAT
+	help
+	  This enables 32 bit time_t support in addition to 64 bit time_t support.
+	  This is relevant on all 32-bit architectures, and 64-bit architectures
+	  as part of compat syscall handling.
+
 config ARCH_NO_COHERENT_DMA_MMAP
 	bool
 
diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index 9b68790013e2..0580cb8c84b2 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 
+generic-y += compat.h
 generic-y += exec.h
 generic-y += export.h
 generic-y += fb.h
diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild
index 4bd5d4369e05..d51bc22e8795 100644
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 generic-y += bugs.h
+generic-y += compat.h
 generic-y += device.h
 generic-y += div64.h
 generic-y += emergency-restart.h
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index 873e3c189279..1d66db9c9db5 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -1,3 +1,4 @@
+generic-y += compat.h
 generic-y += current.h
 generic-y += early_ioremap.h
 generic-y += emergency-restart.h
diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index c00c62e1a4a3..0030f79808b3 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 74bb56f656ef..413dbe530da8 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -30,7 +30,6 @@
 #include <linux/smp.h>
 #include <linux/uaccess.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..0bbac612146e 100644
--- a/arch/arm64/kernel/perf_regs.c
+++ b/arch/arm64/kernel/perf_regs.c
@@ -1,11 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/compat.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/perf_event.h>
 #include <linux/bug.h>
 #include <linux/sched/task_stack.h>
 
-#include <asm/compat.h>
 #include <asm/perf_regs.h>
 #include <asm/ptrace.h>
 
diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild
index fd4c840de837..24037486317c 100644
--- a/arch/c6x/include/asm/Kbuild
+++ b/arch/c6x/include/asm/Kbuild
@@ -1,6 +1,7 @@
 generic-y += atomic.h
 generic-y += barrier.h
 generic-y += bugs.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h
diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild
index 14bac06b7116..a5d0b2991f47 100644
--- a/arch/h8300/include/asm/Kbuild
+++ b/arch/h8300/include/asm/Kbuild
@@ -3,6 +3,7 @@ generic-y += barrier.h
 generic-y += bugs.h
 generic-y += cacheflush.h
 generic-y += checksum.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += delay.h
 generic-y += device.h
diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild
index e9743f689fb8..dd2fd9c0d292 100644
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -2,6 +2,7 @@
 generic-y += barrier.h
 generic-y += bug.h
 generic-y += bugs.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h
diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild
index 6dd867873364..557bbc8ba9f5 100644
--- a/arch/ia64/include/asm/Kbuild
+++ b/arch/ia64/include/asm/Kbuild
@@ -1,3 +1,4 @@
+generic-y += compat.h
 generic-y += exec.h
 generic-y += irq_work.h
 generic-y += mcs_spinlock.h
diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild
index 88a9d27df1ac..4d8d68c4e3dd 100644
--- a/arch/m68k/include/asm/Kbuild
+++ b/arch/m68k/include/asm/Kbuild
@@ -1,4 +1,5 @@
 generic-y += barrier.h
+generic-y += compat.h
 generic-y += device.h
 generic-y += emergency-restart.h
 generic-y += exec.h
diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild
index 3c80a5a308ed..fe6a6c6e5003 100644
--- a/arch/microblaze/include/asm/Kbuild
+++ b/arch/microblaze/include/asm/Kbuild
@@ -2,6 +2,7 @@ generic-y += barrier.h
 generic-y += bitops.h
 generic-y += bug.h
 generic-y += bugs.h
+generic-y += compat.h
 generic-y += device.h
 generic-y += div64.h
 generic-y += emergency-restart.h
diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index 9a0fa66b81ac..3e548ee99a2f 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 c4db910a8794..b5d9e1784aff 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -8,13 +8,13 @@
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  * Copyright (C) 2016, Imagination Technologies Ltd.
  */
+#include <linux/compat.h>
 #include <linux/compiler.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/syscalls.h>
 
-#include <asm/compat.h>
 #include <asm/compat-signal.h>
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
diff --git a/arch/nds32/include/asm/Kbuild b/arch/nds32/include/asm/Kbuild
index 06bdf8167f5a..d1b1f89d44f6 100644
--- a/arch/nds32/include/asm/Kbuild
+++ b/arch/nds32/include/asm/Kbuild
@@ -9,6 +9,7 @@ generic-y += checksum.h
 generic-y += clkdev.h
 generic-y += cmpxchg.h
 generic-y += cmpxchg-local.h
+generic-y += compat.h
 generic-y += cputime.h
 generic-y += device.h
 generic-y += div64.h
diff --git a/arch/nios2/include/asm/Kbuild b/arch/nios2/include/asm/Kbuild
index d232da2cbb38..64ed3d656956 100644
--- a/arch/nios2/include/asm/Kbuild
+++ b/arch/nios2/include/asm/Kbuild
@@ -4,6 +4,7 @@ generic-y += bitops.h
 generic-y += bug.h
 generic-y += bugs.h
 generic-y += cmpxchg.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h
diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild
index f05c722a21f8..65964d390b10 100644
--- a/arch/openrisc/include/asm/Kbuild
+++ b/arch/openrisc/include/asm/Kbuild
@@ -2,6 +2,7 @@ generic-y += barrier.h
 generic-y += bug.h
 generic-y += bugs.h
 generic-y += checksum.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index 57b8b2a2fd4e..0cdfec8857bd 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 62168e1158f1..b4773c81f7d5 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 6bee65f3cfd3..a77528db474c 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -13,6 +13,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include <linux/compat.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
@@ -42,7 +43,6 @@
 #include <asm/paca.h>
 #include <asm/lppaca.h>
 #include <asm/cache.h>
-#include <asm/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..ad054dd0d666 100644
--- a/arch/powerpc/oprofile/backtrace.c
+++ b/arch/powerpc/oprofile/backtrace.c
@@ -7,6 +7,7 @@
  * 2 of the License, or (at your option) any later version.
 **/
 
+#include <linux/compat_time.h>
 #include <linux/oprofile.h>
 #include <linux/sched.h>
 #include <asm/processor.h>
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 9830fb6b076e..501aaff85304 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..7d22a474a040 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -125,8 +125,9 @@
  * ELF register definitions..
  */
 
+#include <linux/compat.h>
+
 #include <asm/ptrace.h>
-#include <asm/compat.h>
 #include <asm/syscall.h>
 #include <asm/user.h>
 
@@ -136,7 +137,6 @@ 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 ebfa0442e569..a3bce0e84346 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -26,7 +26,6 @@
 #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/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild
index 1efcce74997b..46dd82ab2c29 100644
--- a/arch/sh/include/asm/Kbuild
+++ b/arch/sh/include/asm/Kbuild
@@ -1,3 +1,4 @@
+generic-y += compat.h
 generic-y += current.h
 generic-y += delay.h
 generic-y += div64.h
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index 615283e16f22..1910c44521e3 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;
@@ -168,6 +157,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
 	return (u32)(unsigned long)uptr;
 }
 
+#ifdef CONFIG_COMPAT
 static inline void __user *arch_compat_alloc_user_space(long len)
 {
 	struct pt_regs *regs = current_thread_info()->kregs;
@@ -184,6 +174,7 @@ static inline void __user *arch_compat_alloc_user_space(long len)
 
 	return (void __user *) usp;
 }
+#endif
 
 struct compat_ipc64_perm {
 	compat_key_t key;
@@ -243,6 +234,7 @@ struct compat_shmid64_ds {
 	unsigned int	__unused2;
 };
 
+#ifdef CONFIG_COMPAT
 static inline int is_compat_task(void)
 {
 	return test_thread_flag(TIF_32BIT);
@@ -254,5 +246,6 @@ static inline bool in_compat_syscall(void)
 	return pt_regs_trap_type(current_pt_regs()) == 0x110;
 }
 #define in_compat_syscall in_compat_syscall
+#endif
 
 #endif /* _ASM_SPARC64_COMPAT_H */
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
index bb5a196c3061..b10dde6cb793 100644
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -1,6 +1,7 @@
 generic-y += barrier.h
 generic-y += bpf_perf_event.h
 generic-y += bug.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += delay.h
 generic-y += device.h
diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild
index 6f70c76c81fc..bfc7abe77905 100644
--- a/arch/unicore32/include/asm/Kbuild
+++ b/arch/unicore32/include/asm/Kbuild
@@ -1,5 +1,6 @@
 generic-y += atomic.h
 generic-y += bugs.h
+generic-y += compat.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index a6006e7bb729..7a987e6c7c35 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 e1c8dab86670..7cd314b71c51 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -17,7 +17,6 @@
 
 typedef u32		compat_size_t;