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]).
Also note, that fixing setenv() will not fix LSan,
since the culprit is getauxval()
[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1163404
[2]: ClickHouse#32928 (comment)
- 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]: ClickHouse#33840
Fix this by using /proc/self/auxv with fallback to environ solution to
make it compatible with environment that does not allow reading from
auxv (or no procfs).
v2: add fallback to environ solution
v3: fix return value for __auxv_init_procfs()
Refs: #33957
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
Tiny pieces extracted from MUSL library.
git://git.musl-libc.org/musl
c10bc61508dc52b8315084e628f36a6c3c2dabb1
NOTE: Files was edited.
NOTE: Math related files are pulled from commit 6ad514e4e278f0c3b18eb2db1d45638c9af1c07f.
f187c3499a