From nobody Sat Mar 8 08:14:00 2025 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 4Z8wsh6xCRz5qcyZ; Sat, 08 Mar 2025 08:14:00 +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 "R10" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Z8wsh4Zdqz3ktl; Sat, 08 Mar 2025 08:14:00 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1741421640; 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=JLk1Xk4bRGT0vOp6hId8RhK0M8Kmz/8tR0Uy7G2URZ0=; b=wqkY10buXQQlKvw6bXt+1sOeYN5azHGfmvg9uugwMDCxsCVZrYKZHEK0Or6D8MoBODAPK3 E20eX91e8Rqzv/Xv9wcg5EYdp8fZoJc7snFkL204Ifkunl2oHF5JhcIK+j7Igj2b7YCoYD SviN5O2UdiGwsLxxKpA0ma0UQGYSZdI6nYOJ3fY0XOslUqa/sdrUyFjOFb9ALpJvv4OfdF 6l/TsJWZXjQL8eUu4jYMr7wWKqLn26O3C8m7dXI0jpVNyukaUaUMdzQWo97NarXoiUZP8Q YUJJHRTxwrUI9XJhzGfSkPVlwDshWVl46I/hR51XHYre0n3f7qI/0V6oMS52FA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1741421640; a=rsa-sha256; cv=none; b=cNCeOzz1VO7XlxlvMp3tYqAVgl1gpOLynwxoI3JEXGh0czw9u3FG7i0vC1ZJL2Vv+KIraG rL2f79yAA/SVFjrtwSk5bCn/lMdULlABdDb19HS9XG70Uzfqlge/21QlP67MhebceiwdcB 0Oc5eW2yWNnJ7k63hW0CA2fJAfJxaQ42UGroE5V9QdBbVXAOQF6j7ltpUfSe1E2+i3VYfS vppKr5U2YPD5WvWNaD5eRpamiETsU154EWoelONc+DvIb8R8vc5OD1klx5lwpvUDDU98LX r5YVisNP01W384qfwVXB9AU5IS7xQncErexAEdALD7RyTl28AblRbIQf8/9n5g== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1741421640; 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=JLk1Xk4bRGT0vOp6hId8RhK0M8Kmz/8tR0Uy7G2URZ0=; b=Zz+OJahjw4o8OtHzeap74nOsL8vuYoT6AG1cMUFd6Qmb3NIfPGIBT1Oh7lcJDLfxErojKY 76RjormeVUolPwLJIVKK1t5BpV4rqnKMQC4u6XJwYt1KMI7Ep5a8M94DKr0XO3ltB+N12m 3RePg1xdjEaRt8qyOKPhtT2SX8KB+KCKkDEx6ytQpNrB/iCKN7AICsj5es+35dC74fxsxw YUAp/OFQ6y0I8tVMtgZPrzMF9vUcmyxMGbAn0ICQp5C2XvnG2AJ2Zbk4v9rvB5VpYAweXV 9uPV+mwD6je69EeOoSYs/dRvoMr09Pyd76jGQzmLizDfESJ/lwj+p68XFw2QGQ== 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 4Z8wsh41Ymz1CvS; Sat, 08 Mar 2025 08:14:00 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 5288E0wc097769; Sat, 8 Mar 2025 08:14:00 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 5288E0Wq097766; Sat, 8 Mar 2025 08:14:00 GMT (envelope-from git) Date: Sat, 8 Mar 2025 08:14:00 GMT Message-Id: <202503080814.5288E0Wq097766@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: 0ce82e9346a4 - stable/14 - umtx: Fix a bug in do_lock_pp() 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: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/stable/14 X-Git-Reftype: branch X-Git-Commit: 0ce82e9346a4d5ad1d82fac73131afa3a4fc03ac Auto-Submitted: auto-generated The branch stable/14 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=0ce82e9346a4d5ad1d82fac73131afa3a4fc03ac commit 0ce82e9346a4d5ad1d82fac73131afa3a4fc03ac Author: Mark Johnston AuthorDate: 2025-02-22 01:23:31 +0000 Commit: Mark Johnston CommitDate: 2025-03-08 00:37:37 +0000 umtx: Fix a bug in do_lock_pp() If the lock is unowned (i.e., owner == UMUTEX_CONTESTED), we might get a spurious failure, and in that case we need to retry the loop. Otherwise, the calling thread can end up sleeping forever. The same problem exists in do_set_ceiling(), which open-codes do_lock_pp(), so fix it there too. Reviewed by: olce Reported by: Daniel King MFC after: 2 weeks Sponsored by: Innovate UK Differential Revision: https://reviews.freebsd.org/D49031 (cherry picked from commit 4b79443927ec2c53514e73b06eb2a9d241882585) --- sys/kern/kern_umtx.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/sys/kern/kern_umtx.c b/sys/kern/kern_umtx.c index f326b9aa691a..7c01586b4dd7 100644 --- a/sys/kern/kern_umtx.c +++ b/sys/kern/kern_umtx.c @@ -2618,6 +2618,10 @@ do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags, } } else if (owner == UMUTEX_RB_NOTRECOV) { error = ENOTRECOVERABLE; + } else if (owner == UMUTEX_CONTESTED) { + /* Spurious failure, retry. */ + umtxq_unbusy_unlocked(&uq->uq_key); + continue; } if (try != 0) @@ -2824,6 +2828,10 @@ do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling, } else if (owner == UMUTEX_RB_NOTRECOV) { error = ENOTRECOVERABLE; break; + } else if (owner == UMUTEX_CONTESTED) { + /* Spurious failure, retry. */ + umtxq_unbusy_unlocked(&uq->uq_key); + continue; } /*