time: Add new y2038 safe __kernel_timespec

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>

diff --git a/include/linux/time64.h b/include/linux/time64.h
index 93d39499838e06d168dbcefb970d23b047a288ad..0d96887ba4e0bfc95d0523f01aa20117fd8ef3ab 100644 (file)
--- a/include/linux/time64.h
+++ b/include/linux/time64.h
@@ -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

diff --git a/include/uapi/asm-generic/posix_types.h b/include/uapi/asm-generic/posix_types.h
index 5e6ea22bd525ff1772ef278d40f5baa350e8387b..f0733a26ebfc220c163d0fee11f637fedc40e033 100644 (file)
--- a/include/uapi/asm-generic/posix_types.h
+++ b/include/uapi/asm-generic/posix_types.h
@@ -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;

diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h
index 16a296612ba4b0df2359c67aa9c899bec6f719c6..94adfae599e0179c990675d611dc26cab2f9f567 100644 (file)
--- a/include/uapi/linux/time.h
+++ b/include/uapi/linux/time.h
@@ -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