clock_getres: don't assume time_t is 32-bit on 32-bit archs

the time64 syscall for this is not necessary or useful, since clock
resolution is generally better than 68-year granularity. if there's a
32-bit syscall, use it and expand the result into timespec; otherwise
there is only one syscall and it does the right thing to store to
timespec directly.

on 64-bit archs, there is no change to the code after preprocessing.
This commit is contained in:
Rich Felker 2019-07-28 22:53:10 -04:00
parent a02bd52864
commit 244858553e
1 changed files with 14 additions and 0 deletions

View File

@ -3,5 +3,19 @@
int clock_getres(clockid_t clk, struct timespec *ts)
{
#ifdef SYS_clock_getres_time64
/* On a 32-bit arch, use the old syscall if it exists. */
if (SYS_clock_getres != SYS_clock_getres_time64) {
long ts32[2];
int r = __syscall(SYS_clock_getres, clk, ts32);
if (!r) {
ts->tv_sec = ts32[0];
ts->tv_nsec = ts32[1];
}
return __syscall_ret(r);
}
#endif
/* If reaching this point, it's a 64-bit arch or time64-only
* 32-bit arch and we can get result directly into timespec. */
return syscall(SYS_clock_getres, clk, ts);
}