[glibc] y2038: linux: Provide __clock_settime64 implementation
Lukasz Majewski
lukma@sourceware.org
Wed Oct 9 22:20:00 GMT 2019
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=7ce198e1235215df15545a704d6bded4ea728da8
commit 7ce198e1235215df15545a704d6bded4ea728da8
Author: Lukasz Majewski <lukma@denx.de>
Date: Tue Sep 24 14:22:42 2019 +0200
y2038: linux: Provide __clock_settime64 implementation
This patch provides new __clock_settime64 explicit 64 bit function for
setting the time. Moreover, a 32 bit version - __clock_settime - has been
refactored to internally use __clock_settime64.
The __clock_settime is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit
struct timespec.
The new clock_settime64 syscall available from Linux 5.1+ has been used,
when applicable.
In this patch the internal padding (tv_pad) of struct __timespec64 is
left untouched (on systems with __WORDSIZE == 32) as Linux kernel ignores
upper 32 bits of tv_nsec.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with clock_settime64) and glibc build with v5.1 as minimal
kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
__clock_settime64 syscalls.
- Linux v4.19 (no clock_settime64 support) with default minimal kernel
version for contemporary glibc
This kernel doesn't support __clock_settime64 syscalls, so the fallback
to clock_settime is tested.
The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
* include/time.h (__clock_settime64):
Add __clock_settime alias according to __TIMESIZE define
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime):
Refactor this function to be used only on 32 bit machines as a wrapper
on __clock_settime64.
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Add
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64):
Use clock_settime64 kernel syscall (available from 5.1+ Linux)
Diff:
---
ChangeLog | 11 ++++++++++
include/time.h | 8 ++++++++
sysdeps/unix/sysv/linux/clock_settime.c | 36 +++++++++++++++++++++++++++++----
3 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 2e34b2d..edcf1af 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2019-10-10 Ã…Âukasz Majewski <lukma@denx.de>
+
+ * include/time.h (__clock_settime64):
+ Add __clock_settime alias according to __TIMESIZE define
+ * sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime):
+ Refactor this function to be used only on 32 bit machines as a
+ wrapper on __clock_settime64.
+ * sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Add
+ * sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64):
+ Use clock_settime64 kernel syscall (available from 5.1+ Linux)
+
2019-10-09 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* include/spawn.h (__posix_spawn_file_actions_addopen): New
diff --git a/include/time.h b/include/time.h
index f6dc731..d93b16a 100644
--- a/include/time.h
+++ b/include/time.h
@@ -125,6 +125,14 @@ extern __time64_t __timegm64 (struct tm *__tp) __THROW;
libc_hidden_proto (__timegm64)
#endif
+#if __TIMESIZE == 64
+# define __clock_settime64 __clock_settime
+#else
+extern int __clock_settime64 (clockid_t clock_id,
+ const struct __timespec64 *tp);
+libc_hidden_proto (__clock_settime64)
+#endif
+
/* Compute the `struct tm' representation of T,
offset OFFSET seconds east of UTC,
and store year, yday, mon, mday, wday, hour, min, sec into *TP.
diff --git a/sysdeps/unix/sysv/linux/clock_settime.c b/sysdeps/unix/sysv/linux/clock_settime.c
index f76178e..fb48de5 100644
--- a/sysdeps/unix/sysv/linux/clock_settime.c
+++ b/sysdeps/unix/sysv/linux/clock_settime.c
@@ -20,11 +20,9 @@
#include <time.h>
#include <shlib-compat.h>
-#include "kernel-posix-cpu-timers.h"
-
/* Set CLOCK to value TP. */
int
-__clock_settime (clockid_t clock_id, const struct timespec *tp)
+__clock_settime64 (clockid_t clock_id, const struct __timespec64 *tp)
{
/* Make sure the time cvalue is OK. */
if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)
@@ -33,8 +31,38 @@ __clock_settime (clockid_t clock_id, const struct timespec *tp)
return -1;
}
- return INLINE_SYSCALL_CALL (clock_settime, clock_id, tp);
+#ifdef __ASSUME_TIME64_SYSCALLS
+# ifndef __NR_clock_settime64
+# define __NR_clock_settime64 __NR_clock_settime
+# endif
+ return INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp);
+#else
+# ifdef __NR_clock_settime64
+ int ret = INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp);
+ if (ret == 0 || errno != ENOSYS)
+ return ret;
+# endif
+ if (! in_time_t_range (tp->tv_sec))
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+
+ struct timespec ts32 = valid_timespec64_to_timespec (*tp);
+ return INLINE_SYSCALL_CALL (clock_settime, clock_id, &ts32);
+#endif
}
+
+#if __TIMESIZE != 64
+int
+__clock_settime (clockid_t clock_id, const struct timespec *tp)
+{
+ struct __timespec64 ts64 = valid_timespec_to_timespec64 (*tp);
+
+ return __clock_settime64 (clock_id, &ts64);
+}
+#endif
+
libc_hidden_def (__clock_settime)
versioned_symbol (libc, __clock_settime, clock_settime, GLIBC_2_17);
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