[glibc] y2038: Provide conversion helpers for struct __timex64

[glibc] y2038: Provide conversion helpers for struct __timex64

[Lukasz Majewski]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=898f3793164c0e811b28a37827f4bedce334066f

commit 898f3793164c0e811b28a37827f4bedce334066f
Author: Lukasz Majewski <lukma@denx.de>
Date:   Tue Apr 21 19:12:17 2020 +0200

    y2038: Provide conversion helpers for struct __timex64
    
    Those functions allow easy conversion between Y2038 safe, glibc internal
    struct __timex64 and struct timex.
    
    Those functions are put in Linux specific sys/timex.h file, as putting
    them into glibc's local include/time.h would cause build break on HURD as
    it doesn't support struct timex related syscalls.
    
    Build tests:
    ./src/scripts/build-many-glibcs.py glibcs
    
    Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 sysdeps/unix/sysv/linux/include/sys/timex.h | 61 +++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/include/sys/timex.h b/sysdeps/unix/sysv/linux/include/sys/timex.h
index c555509c82..3efe7cd306 100644
--- a/sysdeps/unix/sysv/linux/include/sys/timex.h
+++ b/sysdeps/unix/sysv/linux/include/sys/timex.h
@@ -25,6 +25,7 @@
 
 libc_hidden_proto (__adjtimex)
 
+#  include <time.h>
 #  include <struct___timeval64.h>
 /* Local definition of 64 bit time supporting timex struct */
 #  if __TIMESIZE == 64
@@ -71,5 +72,65 @@ struct __timex64
   int  :32;
 };
 #  endif
+
+/* Convert a known valid struct timex into a struct __timex64.  */
+static inline struct __timex64
+valid_timex_to_timex64 (const struct timex tx)
+{
+  struct __timex64 tx64;
+
+  tx64.modes = tx.modes;
+  tx64.offset = tx.offset;
+  tx64.freq = tx.freq;
+  tx64.maxerror = tx.maxerror;
+  tx64.esterror = tx.esterror;
+  tx64.status = tx.status;
+  tx64.constant = tx.constant;
+  tx64.precision = tx.precision;
+  tx64.tolerance = tx.tolerance;
+  tx64.time = valid_timeval_to_timeval64 (tx.time);
+  tx64.tick = tx.tick;
+  tx64.ppsfreq = tx.ppsfreq;
+  tx64.jitter = tx.jitter;
+  tx64.shift = tx.shift;
+  tx64.stabil = tx.stabil;
+  tx64.jitcnt = tx.jitcnt;
+  tx64.calcnt = tx.calcnt;
+  tx64.errcnt = tx.errcnt;
+  tx64.stbcnt = tx.stbcnt;
+  tx64.tai = tx.tai;
+
+  return tx64;
+}
+
+/* Convert a known valid struct __timex64 into a struct timex.  */
+static inline struct timex
+valid_timex64_to_timex (const struct __timex64 tx64)
+{
+  struct timex tx;
+
+  tx.modes = tx64.modes;
+  tx.offset = tx64.offset;
+  tx.freq = tx64.freq;
+  tx.maxerror = tx64.maxerror;
+  tx.esterror = tx64.esterror;
+  tx.status = tx64.status;
+  tx.constant = tx64.constant;
+  tx.precision = tx64.precision;
+  tx.tolerance = tx64.tolerance;
+  tx.time = valid_timeval64_to_timeval (tx64.time);
+  tx.tick = tx64.tick;
+  tx.ppsfreq = tx64.ppsfreq;
+  tx.jitter = tx64.jitter;
+  tx.shift = tx64.shift;
+  tx.stabil = tx64.stabil;
+  tx.jitcnt = tx64.jitcnt;
+  tx.calcnt = tx64.calcnt;
+  tx.errcnt = tx64.errcnt;
+  tx.stbcnt = tx64.stbcnt;
+  tx.tai = tx64.tai;
+
+  return tx;
+}
 # endif /* _ISOMAC */
 #endif /* sys/timex.h */