y2038: Introduce struct __timespec64 - new internal glibc type

This type is a glibc's "internal" type similar to struct timespec but
whose tv_sec field is a __time64_t rather than a time_t, which makes it
Y2038-proof and usable to pass syscalls between user code and Y2038-proof
kernel.

To support passing this structure to the kernel - the unnamed 32 bit
padding bit-field has been introduced. The placement of it depends on
the endianness of the SoC.

Tested on x86_64 and ARM.
This commit is contained in:
Lukasz Majewski 2019-03-22 11:53:45 +01:00
parent 8b45cac079
commit 464cd3a9d5
2 changed files with 28 additions and 0 deletions

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@ -1,3 +1,7 @@
2019-09-26 Lukasz Majewski <lukma@denx.de>
* include/time.h: Add struct __timespec64 definition
2019-09-26 Siddhesh Poyarekar <siddhesh@gotplt.org>
* scripts/vcs_to_changelog/misc_util.py (decode): Remove latin1

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@ -5,6 +5,7 @@
# include <bits/types/locale_t.h>
# include <stdbool.h>
# include <time/mktime-internal.h>
# include <endian.h>
extern __typeof (strftime_l) __strftime_l;
libc_hidden_proto (__strftime_l)
@ -49,6 +50,29 @@ extern void __tzset_parse_tz (const char *tz) attribute_hidden;
extern void __tz_compute (__time64_t timer, struct tm *tm, int use_localtime)
__THROW attribute_hidden;
#if __TIMESIZE == 64
# define __timespec64 timespec
#else
/* The glibc Y2038-proof struct __timespec64 structure for a time value.
To keep things Posix-ish, we keep the nanoseconds field a 32-bit
signed long, but since the Linux field is a 64-bit signed int, we
pad our tv_nsec with a 32-bit unnamed bit-field padding.
As a general rule the Linux kernel is ignoring upper 32 bits of
tv_nsec field. */
struct __timespec64
{
__time64_t tv_sec; /* Seconds */
# if BYTE_ORDER == BIG_ENDIAN
__int32_t :32; /* Padding */
__int32_t tv_nsec; /* Nanoseconds */
# else
__int32_t tv_nsec; /* Nanoseconds */
__int32_t :32; /* Padding */
# endif
};
#endif
#if __TIMESIZE == 64
# define __ctime64 ctime
#else