From nobody Sat Apr 19 10:29:09 2025 X-Original-To: current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4ZfntS1vrsz5t9xN for ; Sat, 19 Apr 2025 10:29:20 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4ZfntQ4hl5z3jh3; Sat, 19 Apr 2025 10:29:18 +0000 (UTC) (envelope-from kostikbel@gmail.com) Authentication-Results: mx1.freebsd.org; none Received: from tom.home (kib@localhost [127.0.0.1] (may be forged)) by kib.kiev.ua (8.18.1/8.18.1) with ESMTP id 53JATADI045565; Sat, 19 Apr 2025 13:29:13 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 53JATADI045565 Received: (from kostik@localhost) by tom.home (8.18.1/8.18.1/Submit) id 53JATAdP045564; Sat, 19 Apr 2025 13:29:10 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sat, 19 Apr 2025 13:29:09 +0300 From: Konstantin Belousov To: Andriy Gapon Cc: FreeBSD Current Subject: Re: RTLD_DEEPBIND question Message-ID: References: <0b3dda4e-53e4-40e5-9484-8b5ffb84e658@FreeBSD.org> <900c8521-559a-47b5-acaa-ae941f6852c4@freebsd.org> <7c4e1682-d797-493c-8326-08d51dde3359@FreeBSD.org> List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7c4e1682-d797-493c-8326-08d51dde3359@FreeBSD.org> X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on tom.home X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US] X-Rspamd-Queue-Id: 4ZfntQ4hl5z3jh3 X-Spamd-Bar: ---- On Sat, Apr 19, 2025 at 01:25:28PM +0300, Andriy Gapon wrote: > On 19/04/2025 12:39, Andriy Gapon wrote: > > On 19/04/2025 12:25, Andriy Gapon wrote: > > > On 19/04/2025 02:41, Konstantin Belousov wrote: > > > > RTLD_DEEPBIND works by first iterating over all (recursive) DT_NEEEDED > > > > object for the object where the symbol is resolved, then by looking at > > > > the global list of loaded objects. > > > > Non-deepbind resolution is performed by looking at the global list. > > > > > > > > You can see it in the rtld.c:symlook_default(). > > > > From a quick look at the code, should we try to resolve the symbol in > > refobj itself when it's marked with deepbind? > Oh, and it looks like objects loaded under the "deepbind" object (e.g., > needed objects) may not be aware that they are in the deepbind sub-tree? But should they? Lets start with some minimal intrusive change: commit b4f4feb883a1be1d4ca3867f49baa20ce0c13d8d Author: Konstantin Belousov Date: Sat Apr 19 13:26:58 2025 +0300 rtld: symbolic and deepbind are equivalent for the refobj Reported by: avg diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c index 2346c6eae9f6..8ea6afb43752 100644 --- a/libexec/rtld-elf/rtld.c +++ b/libexec/rtld-elf/rtld.c @@ -4679,12 +4679,13 @@ symlook_default(SymLook *req, const Obj_Entry *refobj) */ res = symlook_obj(&req1, refobj); if (res == 0 && (refobj->symbolic || - ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { + ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || + refobj->deepbind)) { req->sym_out = req1.sym_out; req->defobj_out = req1.defobj_out; assert(req->defobj_out != NULL); } - if (refobj->symbolic || req->defobj_out != NULL) + if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) donelist_check(&donelist, refobj); if (!refobj->deepbind)