From owner-freebsd-bugs@freebsd.org Fri Jan 8 14:47:35 2016 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 AD40AA684A1 for ; Fri, 8 Jan 2016 14:47:35 +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 859B91014 for ; Fri, 8 Jan 2016 14:47:35 +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 u08ElZtN015013 for ; Fri, 8 Jan 2016 14:47:35 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 206035] gpiobus causes panic when attached to gpio with a single pin Date: Fri, 08 Jan 2016 14:47:35 +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-CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: sgalabov@gmail.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 attachments.created 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: 2.1.20 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Jan 2016 14:47:35 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D206035 Bug ID: 206035 Summary: gpiobus causes panic when attached to gpio with a single pin Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: sgalabov@gmail.com Created attachment 165265 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D165265&action= =3Dedit Suggested fix for the problem (please see comments for details) While attaching a gpiobus to a GPIO controller with a single pin, the system panics due to a failed KASSERT in gpiobus_init_softc(). This is due to the fact that gpiobus obtains the maximum pin number from the GPIO controller (via GPIO_PIN_MAX) and immediately does a KASSERT, expecting that the obtained value is !=3D 0. In the case of a GPIO controller which controls a single pin, the returned value will be 0 (0 is the maximum pin number), which is absolutely valid. Moreover, right after the KASSERT the code in gpiobus_init_softc() actually adjusts the number of pins to the right value. The suggestion is to change the KASSERT like so: - KASSERT(sc->sc_npins !=3D 0, ("GPIO device with no pins")); + KASSERT(sc->sc_npins >=3D 0, ("GPIO device with no pins")); This, I believe, is a better approach than, say, simply postponing the KASS= ERT until after gpiobus has adjusted the number of pins, since if a broken GPIO controller driver returns a < 0 value we'll be in even more trouble. I've attached a patch with the suggested fix. --=20 You are receiving this mail because: You are the assignee for the bug.=