[PATCH 1/2] y2038: make CONFIG_64BIT_TIME unconditional

[PATCH 1/2] y2038: make CONFIG_64BIT_TIME unconditional

[Arnd Bergmann]

As Stepan Golosunov points out, we made a small mistake in the
get_timespec64() function in the kernel. It was originally added under
the assumption that CONFIG_64BIT_TIME would get enabled on all 32-bit
and 64-bit architectures, but when I did the conversion, I only turned
it on for 32-bit ones.

The effect is that the get_timespec64() function never clears the upper
half of the tv_nsec field for 32-bit tasks in compat mode. Clearing this
is required for POSIX compliant behavior of functions that pass a
'timespec' structure with a 64-bit tv_sec and a 32-bit tv_nsec, plus
uninitialized padding.

The easiest fix for linux-5.1 is to just make the Kconfig symbol
unconditional, as it was originally intended. As a follow-up,
we should remove any #ifdef CONFIG_64BIT_TIME completely.

Note: for native 32-bit mode, no change is needed, this works as
designed and user space should never need to clear the upper 32
bits of the tv_nsec field, in or out of the kernel.

Fixes: 00bf25d693e7 ("y2038: use time32 syscall names on 32-bit")
Link: https://lore.kernel.org/lkml/20190422090710.bmxdhhankurhafxq@sghpc.golosunov.pp.ru/
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Stepan Golosunov <stepan@golosunov.pp.ru>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Please apply this one as a bugfix for 5.1
---
 arch/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 33687dddd86a..9092e0ffe4d3 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -764,7 +764,7 @@ config COMPAT_OLD_SIGACTION
 	bool
 
 config 64BIT_TIME
-	def_bool ARCH_HAS_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
-- 
2.20.0

[PATCH 2/2] y2038: remove CONFIG_64BIT_TIME

[Arnd Bergmann]

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>
---
This would make sense for 5.2, or could be part of a later
cleanup series when I have more patches for the remaining
y2038 bits
---
 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 9092e0ffe4d3..23ee740182aa 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -763,14 +763,6 @@ 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 3490d1fa0e16..b1b949ae1a93 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -2057,7 +2057,7 @@ 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 41dfff23c1f9..61f03faf783a 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1749,7 +1749,7 @@ 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 74105fa3ce80..a4c72577aa92 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -264,7 +264,7 @@ 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 */
@@ -871,7 +871,7 @@ 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 a180e1a9ff23..2ff80e03d97b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2787,7 +2787,7 @@ 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

[tip:timers/urgent] y2038: Make CONFIG_64BIT_TIME unconditional

[tip-bot for Arnd Bergmann]

Commit-ID:  f3d964673b2f1c5d5c68c77273efcf7103eed03b
Gitweb:     https://git.kernel.org/tip/f3d964673b2f1c5d5c68c77273efcf7103eed03b
Author:     Arnd Bergmann <arnd@arndb.de>
AuthorDate: Mon, 29 Apr 2019 15:19:37 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 29 Apr 2019 21:07:10 +0200

y2038: Make CONFIG_64BIT_TIME unconditional

As Stepan Golosunov points out, there is a small mistake in the
get_timespec64() function in the kernel. It was originally added under the
assumption that CONFIG_64BIT_TIME would get enabled on all 32-bit and
64-bit architectures, but when the conversion was done, it was only turned
on for 32-bit ones.

The effect is that the get_timespec64() function never clears the upper
half of the tv_nsec field for 32-bit tasks in compat mode. Clearing this is
required for POSIX compliant behavior of functions that pass a 'timespec'
structure with a 64-bit tv_sec and a 32-bit tv_nsec, plus uninitialized
padding.

The easiest fix for linux-5.1 is to just make the Kconfig symbol
unconditional, as it was originally intended. As a follow-up, the #ifdef
CONFIG_64BIT_TIME can be removed completely..

Note: for native 32-bit mode, no change is needed, this works as
designed and user space should never need to clear the upper 32
bits of the tv_nsec field, in or out of the kernel.

Fixes: 00bf25d693e7 ("y2038: use time32 syscall names on 32-bit")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joseph Myers <joseph@codesourcery.com>
Cc: libc-alpha@sourceware.org
Cc: linux-api@vger.kernel.org
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Stepan Golosunov <stepan@golosunov.pp.ru>
Link: https://lore.kernel.org/lkml/20190422090710.bmxdhhankurhafxq@sghpc.golosunov.pp.ru/
Link: https://lkml.kernel.org/r/20190429131951.471701-1-arnd@arndb.de

---
 arch/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 33687dddd86a..9092e0ffe4d3 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -764,7 +764,7 @@ config COMPAT_OLD_SIGACTION
 	bool
 
 config 64BIT_TIME
-	def_bool ARCH_HAS_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

[PATCH 2/2] y2038: remove CONFIG_64BIT_TIME

[Arnd Bergmann]

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>
---
This would make sense for 5.2, or could be part of a later
cleanup series when I have more patches for the remaining
y2038 bits
---
 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 9092e0ffe4d3..23ee740182aa 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -763,14 +763,6 @@ 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 3490d1fa0e16..b1b949ae1a93 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -2057,7 +2057,7 @@ 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 41dfff23c1f9..61f03faf783a 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1749,7 +1749,7 @@ 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 74105fa3ce80..a4c72577aa92 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -264,7 +264,7 @@ 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 */
@@ -871,7 +871,7 @@ 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 a180e1a9ff23..2ff80e03d97b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2787,7 +2787,7 @@ 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

[PATCH 2/2] y2038: remove CONFIG_64BIT_TIME

[Arnd Bergmann]

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>
---
This would make sense for 5.2, or could be part of a later
cleanup series when I have more patches for the remaining
y2038 bits
---
 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 9092e0ffe4d3..23ee740182aa 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -763,14 +763,6 @@ 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 3490d1fa0e16..b1b949ae1a93 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -2057,7 +2057,7 @@ 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 41dfff23c1f9..61f03faf783a 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1749,7 +1749,7 @@ 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 74105fa3ce80..a4c72577aa92 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -264,7 +264,7 @@ 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 */
@@ -871,7 +871,7 @@ 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 a180e1a9ff23..2ff80e03d97b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2787,7 +2787,7 @@ 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

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