[PATCH release/2.42/master] stdlib: resolve a double lock init issue after fork [BZ #32994]

[Florian Weimer]

* Mark Wielaard:

> From: Davide Cavalca <davide@cavalca.name>
>
> The __abort_fork_reset_child (introduced in
> d40ac01cbbc66e6d9dbd8e3485605c63b2178251) call resets the lock after the
> fork. This causes a DRD regression in valgrind
> (https://bugs.kde.org/show_bug.cgi?id=503668), as it's effectively a
> double initialization, despite it being actually ok in this case. As
> suggested in https://sourceware.org/bugzilla/show_bug.cgi?id=32994#c2
> we replace it here with a memcpy of another initialized lock instead,
> which makes valgrind happy.
>
> Reviewed-by: Florian Weimer <fweimer@redhat.com>
> (cherry picked from commit d9a348d0927c7a1aec5caf3df3fcd36956b3eb23)

Okay.

(Backports, if posted at all, should be posted to libc-stable, but it
doesn't really matter.)

Thanks,
Florian