From owner-dev-commits-src-all@freebsd.org Fri Jun 18 21:49:12 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 4868864DD1E; Fri, 18 Jun 2021 21:49:12 +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 4G6CHX00Bzz3McC; Fri, 18 Jun 2021 21:49:11 +0000 (UTC) (envelope-from git@FreeBSD.org) 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 B0FC7242E; Fri, 18 Jun 2021 21:49:11 +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 15ILnBrL069323; Fri, 18 Jun 2021 21:49:11 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 15ILnBRP069322; Fri, 18 Jun 2021 21:49:11 GMT (envelope-from git) Date: Fri, 18 Jun 2021 21:49:11 GMT Message-Id: <202106182149.15ILnBRP069322@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: "Bjoern A. Zeeb" Subject: git: 46ae23a4024b - main - LinuxKPI: avoid userret: Returning with with pinned thread MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: bz X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 46ae23a4024b792c44a2b6c5f80429c40dac120b Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jun 2021 21:49:12 -0000 The branch main has been updated by bz: URL: https://cgit.FreeBSD.org/src/commit/?id=46ae23a4024b792c44a2b6c5f80429c40dac120b commit 46ae23a4024b792c44a2b6c5f80429c40dac120b Author: Bjoern A. Zeeb AuthorDate: 2021-06-09 18:53:16 +0000 Commit: Bjoern A. Zeeb CommitDate: 2021-06-18 21:20:10 +0000 LinuxKPI: avoid userret: Returning with with pinned thread Some code manually calls local_bh_disable() and spin_lock() but then calls spin_unlock_bh() (or vice versa). Our code then calls local_bh_disable() again from spin_lock() which means we have the thread pin count increased twice and that means we get out of synch and are still pinned when returning to user space. Avoid this by adding the explicit local_bh_{enable,disable}() to the spin_[un]lock_bh() versions. Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Reviewed by: hselasky Differential Revision: https://reviews.freebsd.org/D30711 --- sys/compat/linuxkpi/common/include/linux/spinlock.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sys/compat/linuxkpi/common/include/linux/spinlock.h b/sys/compat/linuxkpi/common/include/linux/spinlock.h index 83f45b1a2a40..ca51fd23434c 100644 --- a/sys/compat/linuxkpi/common/include/linux/spinlock.h +++ b/sys/compat/linuxkpi/common/include/linux/spinlock.h @@ -66,6 +66,7 @@ typedef struct { #define spin_lock_bh(_l) do { \ spin_lock(_l); \ + local_bh_disable(); \ } while (0) #define spin_lock_irq(_l) do { \ @@ -80,6 +81,7 @@ typedef struct { } while (0) #define spin_unlock_bh(_l) do { \ + local_bh_enable(); \ spin_unlock(_l); \ } while (0)