getauxval() from glibc-compatibility did not work always correctly:
- it does not work after setenv(), and this breaks vsyscalls,
like sched_getcpu() [1] (and BaseDaemon.cpp always set TZ if timezone
is defined, which is true for CI [2]).
[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1163404
[2]: https://github.com/ClickHouse/ClickHouse/pull/32928#issuecomment-1015762717
- another think that is definitely broken is LSan (Leak Sanitizer), it
relies on worked getauxval() but it does not work if __environ is not
initialized yet (there is even a commit about this).
And because of, at least, one leak had been introduced [3]:
[3]: https://github.com/ClickHouse/ClickHouse/pull/33840
Fix this by using /proc/self/auxv.
And let's see how many issues will LSan find...
I've verified this patch manually by printing AT_BASE and compared it
with output of LD_SHOW_AUXV.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
