From owner-freebsd-bugs@freebsd.org Fri Jun 16 07:59:31 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 10DA9BF96D2 for ; Fri, 16 Jun 2017 07:59:31 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id F3A7B74FF4 for ; Fri, 16 Jun 2017 07:59:30 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v5G7xUBG086367 for ; Fri, 16 Jun 2017 07:59:30 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 220032] [if_alc] sys/dev/alc/if_alc.c: sleep-under-mutex bugs Date: Fri, 16 Jun 2017 07:59:31 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: baijiaju1990@163.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Jun 2017 07:59:31 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D220032 Bug ID: 220032 Summary: [if_alc] sys/dev/alc/if_alc.c: sleep-under-mutex bugs Product: Base System Version: 11.0-RELEASE Hardware: i386 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: baijiaju1990@163.com The alc driver may sleep under a mutex, and the function call paths in file "sys/dev/alc/if_alc.c" in FreeBSD 11.0 is: alc_resume [line 2648: acquire the mutex] alc_init_locked [line 2664] alc_init_rx_ring [line 3911] alc_newbuf [line 4469] bus_dmamap_load_mbuf_sg(BUS_DMA_WAITOK) [line 3472] --> may sleep alc_int_task [line 3330: acquire the mutex] alc_start_locked [line 3372] alc_encap [line 2942] bus_dmamap_load_mbuf_sg(BUS_DMA_WAITOK) [line 2780] --> may sleep The possible fix of these bugs is to set the last parameter in bus_dmamap_load_mbuf_sg to "BUS_DMA_NOWAIT". This bug is found by a static analysis tool written by myself, and it is checked by my review of the FreeBSD code. By the way, I am a freshman in developing FreeBSD drivers, and I am willing= to submit a patch. But I do not know how to write and submit a patch, and wher= e to submit, so I am looking forward to useful advice :) Jia-Ju Bai --=20 You are receiving this mail because: You are the assignee for the bug.=