time: Add new y2038 safe __kernel_timespec (acf8870a) · Commits · 戴 / test

The new struct __kernel_timespec is similar to current internal kernel struct timespec64 on 64 bit architecture. The compat structure however is similar to below on little endian systems (padding and tv_nsec are switched for big endian systems): typedef s32 compat_long_t; typedef s64 compat_kernel_time64_t; struct compat_kernel_timespec { compat_kernel_time64_t tv_sec; compat_long_t tv_nsec; compat_long_t padding; }; This allows for both the native and compat representations to be the same and syscalls using this type as part of their ABI can have a single entry point to both. Note that the compat define is not included anywhere in the kernel explicitly to avoid confusion. These types will be used by the new syscalls that will be introduced in the consequent patches. Most of the new syscalls are just an update to the existing native ones with this new type. Hence, put this new type under an ifdef so that the architectures can define CONFIG_64BIT_TIME when they are ready to handle this switch. Cc: linux-arch@vger.kernel.org Signed-off-by:

Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by:

Arnd Bergmann <arnd@arndb.de>

include/linux/time64.h

+9 −1

Original line number	Diff line number	Diff line
		@@ -2,12 +2,20 @@
		#ifndef _LINUX_TIME64_H
		#define _LINUX_TIME64_H

		#include <uapi/linux/time.h>
		#include <linux/math64.h>

		typedef __s64 time64_t;
		typedef __u64 timeu64_t;

		/* CONFIG_64BIT_TIME enables new 64 bit time_t syscalls in the compat path
		* and 32-bit emulation.
		*/
		#ifndef CONFIG_64BIT_TIME
		#define __kernel_timespec timespec
		#endif

		#include <uapi/linux/time.h>

		#if __BITS_PER_LONG == 64
		/* this trick allows us to optimize out timespec64_to_timespec */
		# define timespec64 timespec

include/uapi/asm-generic/posix_types.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -87,6 +87,7 @@ typedef struct {
		typedef __kernel_long_t __kernel_off_t;
		typedef long long __kernel_loff_t;
		typedef __kernel_long_t __kernel_time_t;
		typedef long long __kernel_time64_t;
		typedef __kernel_long_t __kernel_clock_t;
		typedef int __kernel_timer_t;
		typedef int __kernel_clockid_t;

include/uapi/linux/time.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,13 @@ struct itimerval {
		struct timeval it_value; /* current value */
		};

		#ifndef __kernel_timespec
		struct __kernel_timespec {
		__kernel_time64_t tv_sec; /* seconds */
		long long tv_nsec; /* nanoseconds */
		};
		#endif

		/*
		* legacy timeval structure, only embedded in structures that
		* traditionally used 'timeval' to pass time intervals (not absolute

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