From nobody Tue Jun 7 14:23:29 2022 X-Original-To: dev-commits-src-all@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 B09AA7CAE07; Tue, 7 Jun 2022 14:23:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (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-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4LHXdt1V7rz3r8F; Tue, 7 Jun 2022 14:23:30 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1654611810; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=SAZY7uQ5LxzDUqpFzprLrkGv+cbGwpz1M/usG+wVhP0=; b=AKZLFwik8b4Q6YOto9tdJuZhnIOGd5vJkN9ACStOTj/y17b6oGIpI7FmaD9jYs9jpV3Dl+ Tp2LAP2XfoFag3bMBUHv/mdpAyWgoJ7qNHRKhjDWQffm5A1HtRNzecu+NqeJ6S/HekcAuh bAnwTHdzif0fz9GviKB3zHKX4ZUs47HbaIoHeIQ5mf558BXBym5GZZER9TA2oI2OJjblYN 2bQjKG7laYs6aGLrkI3zWaCNIUO1kK+9EdQj0z3ZlEjryB2CY6IzfYImeq6yIwY9KUSZDs +ZdygbFK/TKThyIp7nNXUltQXQPi0/6waJ2dAesNWOFbGOWIue2PC4bWa6B/0w== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 0EB801C8B8; Tue, 7 Jun 2022 14:23:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 257ENT4h020308; Tue, 7 Jun 2022 14:23:29 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 257ENTOW020307; Tue, 7 Jun 2022 14:23:29 GMT (envelope-from git) Date: Tue, 7 Jun 2022 14:23:29 GMT Message-Id: <202206071423.257ENTOW020307@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Andrew Turner Subject: git: 3f10d87df48a - stable/13 - Handle cas failure when the compare succeeds List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: andrew X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 3f10d87df48a49136ea9ceefbe8171f24546f27c Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1654611810; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=SAZY7uQ5LxzDUqpFzprLrkGv+cbGwpz1M/usG+wVhP0=; b=UxoQ4kBTFbXw9vHR1VP5ezRNFqC7iDD6ZkcKDhtQbiNbKGN/DvI5BwMJzbPkM9Ql6PrhIi k4ykkN/nkcroiM563QcoW5kTwVrxEi6G4SHNYVEivfTe8GgTIxxcaI+C3JtTGK5175oyHN NsH913K+cBC3MJLxGwMhwGcHUpVzmrZTIQ5UTmoZusCv5LBssO1UDT/3lXb0928/U4rWys GlxDAd0bskh3Tfj4JPeHIfx9QGlai6qc6q5s8AVKmvUC/FmePUCyKDcz5qOwKaECq87P7B Ld0iSVyv5iBZzglwqVfKq4Fe+OztYwt7IxMoRaM+bcVUZ4wQvWIbLmcNF31Kvg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1654611810; a=rsa-sha256; cv=none; b=yOuCLDAvbGRulhJeL+Nu7lFW6WSLpOm7c264UvDb7pTJ1Mil2kXzyOurWsbH7GsrDhTgp2 MIzrNZBr2yjPXIcy/O7CsdtJ/1W/OhOqX22qiDy3rxKD1XOYCGtqlUmBW61KFb7osAAcbD MGP5InIu1RPseVkTFJg3mSSmAzASGYSLBVqIrxnAJGleCiKLAJ/YIawPeWLYk2BUXb5nDj CwhhBRZl7FI4Fs+ydSFzNcXGYfN2O0DgKOVnkVT0AFio28n4Uc08AZTbQwmLw2qELApRNg KxPVvzDX0vAGaxW87F3g9EmCinnajQphIpV8AIzG87v6CyDW5IMRcea8XX726g== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=3f10d87df48a49136ea9ceefbe8171f24546f27c commit 3f10d87df48a49136ea9ceefbe8171f24546f27c Author: Andrew Turner AuthorDate: 2022-05-09 14:28:56 +0000 Commit: Andrew Turner CommitDate: 2022-06-07 14:20:18 +0000 Handle cas failure when the compare succeeds When locking a priority inherit mutex we perform a compare and swap operation to try and acquire the mutex. This may fail even when the compare succeeds. Check and handle this case. PR: 263825 Reviewed by: kib, markj Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D35150 (cherry picked from commit 11a6ecd4258b9108fb19420ec5db297f6d99a842) --- sys/kern/kern_umtx.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/sys/kern/kern_umtx.c b/sys/kern/kern_umtx.c index b76d080b8e06..dd1622c476c5 100644 --- a/sys/kern/kern_umtx.c +++ b/sys/kern/kern_umtx.c @@ -2223,6 +2223,17 @@ do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags, break; } + /* + * Nobody owns it, but the acquire failed. This can happen + * with ll/sc atomics. + */ + if (owner == UMUTEX_UNOWNED) { + error = thread_check_susp(td, true); + if (error != 0) + break; + continue; + } + /* * Avoid overwriting a possible error from sleep due * to the pending signal with suspension check result.