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| author | Arnd Bergmann <arnd@arndb.de> | 2019-04-29 15:19:37 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-04-29 21:07:10 +0200 |
| commit | f3d964673b2f1c5d5c68c77273efcf7103eed03b (patch) | |
| tree | 60e92616157ebaf5d0223573ac1f5c0904d8a4fb /arch/Kconfig | |
| parent | x86: make ZERO_PAGE() at least parse its argument (diff) | |
| download | linux-f3d964673b2f1c5d5c68c77273efcf7103eed03b.tar.xz linux-f3d964673b2f1c5d5c68c77273efcf7103eed03b.zip | |
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
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
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 |