From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.gentoo.org (woodpecker.gentoo.org [140.211.166.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 907B17E for ; Wed, 15 Mar 2023 04:24:03 +0000 (UTC) User-agent: mu4e 1.8.14; emacs 29.0.60 From: Sam James To: distributions@lists.linux.dev Subject: libevent changes ABI on >=glibc-2.36 upgrade, breaking e.g. Tor Date: Wed, 15 Mar 2023 04:20:29 +0000 Message-ID: <878rfy7icf.fsf@gentoo.org> Precedence: bulk X-Mailing-List: distributions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" --=-=-= Content-Type: text/plain libevent hasn't made a release in a while, so this is probably worth getting out there. If libevent is built against a libc without arc4random, like <=glibc-2.36, it'll provide evutil_secure_rng_add_bytes. If it's built against a libc providing arc4random, it'll stop providing evutil_secure_rng_add_bytes without changing SONAME. This breaks consumers like Tor which uses it if it exists in libevent, leading to runtime issues: ``` Feb 15 04:57:23 systemd[1]: Starting tor.service... Feb 15 04:57:23 tor[1321]: /usr/bin/tor: symbol lookup error: /usr/bin/tor: undefined symbol: evutil_secure_rng_add_bytes ``` This originally bit us in Gentoo [0] and there's an upstream bug report [1] and patch available now (but no new release) to always provide evutil_secure_rng_add_bytes, but stubbed out if libc provides arc4random. [0] https://bugs.gentoo.org/894536 [1] https://github.com/libevent/libevent/issues/1393 [2] https://github.com/libevent/libevent/pull/1427 best, sam --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iOUEARYKAI0WIQQlpruI3Zt2TGtVQcJzhAn1IN+RkAUCZBFIYF8UgAAAAAAuAChp c3N1ZXItZnByQG5vdGF0aW9ucy5vcGVucGdwLmZpZnRoaG9yc2VtYW4ubmV0MjVB NkJCODhERDlCNzY0QzZCNTU0MUMyNzM4NDA5RjUyMERGOTE5MA8cc2FtQGdlbnRv by5vcmcACgkQc4QJ9SDfkZDMnwEAi5+jt9YrQzx1poeHN+EV6UaoJlr9Jc3HTpNa gAvHIiIBAMfOPUyXwF3McUdQ6TcZsKLe2ay9QQavohON32IDkIAI =xoSx -----END PGP SIGNATURE----- --=-=-=--