gettimeofday((void *)-1, NULL) implicates core dump on recent FreeBSD 11-CURRENT
NGie Cooper
yaneurabeya at gmail.com
Thu Jul 9 09:17:51 UTC 2015
On Thu, Jul 9, 2015 at 1:41 AM, Konstantin Belousov <kostikbel at gmail.com> wrote:
> On Thu, Jul 09, 2015 at 08:27:17AM +1000, Peter Jeremy wrote:
>> I'm not sure if we want to explicitly document the conditions under which
>> gettimeofday() (or clock_gettime()) are implemented in userland vs syscalls
>> because that is guaranteed to get stale over time. How about stating that
> Of course, we don't. There is no guarantee that the set of conditions
> is stable even on the stable branch.
>
>> these functions are implemented as syscalls only if the AT_TIMEKEEP value
>> reported by "procstat -x" is NULL.
> Mere presence of AT_TIMEKEEP does not imply the use of the fast path.
> E.g. the fast path can be disabled dynamically, or timecounter could be
> changed, or libc might be of the wrong version. My imagination stops
> there.
>
> IMO the point of this discussion is to note that test suite tests useless
useless -> inapplicable
> things.
things. -> things [for FreeBSD].
> If somebody run the test suite for libc, she would immediately note
> another failing test for the stack protector, which is similar to the
> gettimeofday nonsense.
Perhaps, but that's assuming that NetBSD implemented gettimeofday in
userland, which is doesn't.
I agree that this is less applicable for FreeBSD than NetBSD. Please
keep in mind that contrib/netbsd-tests came from NetBSD, not FreeBSD.
Peter Holm and I tried our best to vet out the issues with the test
suite before integrating it in, but there might be issues due to
implementation discrepancies between FreeBSD and NetBSD.
Thanks,
-NGie
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