Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755099Ab1FRLDB (ORCPT ); Sat, 18 Jun 2011 07:03:01 -0400 Received: from mail-pz0-f51.google.com ([209.85.210.51]:43750 "EHLO mail-pz0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754687Ab1FRLDA convert rfc822-to-8bit (ORCPT ); Sat, 18 Jun 2011 07:03:00 -0400 X-Greylist: delayed 332 seconds by postgrey-1.27 at vger.kernel.org; Sat, 18 Jun 2011 07:02:59 EDT DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=tyM1t8AuXrVeZymqqSwVc9U2RyRpe5AQ6siDa1mbVWvNgByHCBocRPdz9PJT0jlZdP hiNr0jJZbrQQ3gjNf9w2a4W5z0w9yi9EoftEi0PlfsJ7xMJwqDYhqb/Efrlhrf3ne3p2 p+8Syyv/twVBSvbtnnMa8BMxfMTJcdKNjuFWw= MIME-Version: 1.0 In-Reply-To: <20110618133957.378b5266@farn.lan> References: <20110618133957.378b5266@farn.lan> Date: Sat, 18 Jun 2011 12:57:26 +0200 Message-ID: Subject: Re: Lock up when faking MMIO read[bwl] on some machines [WAS: Faking MMIO ops? Fooling a driver] From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= To: Pekka Paalanen Cc: Linux Kernel Mailing List , linux-wireless@vger.kernel.org, Larry Finger Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1962 Lines: 46 W dniu 18 czerwca 2011 12:39 użytkownik Pekka Paalanen napisał: > On Sat, 18 Jun 2011 00:31:32 +0200 > Rafał Miłecki wrote: > >> I use attached patch to fake result of read[bwl] performed by >> closed source driver (ndiswrapper+bcmwl and wl). >> >> 1) It works great on my Sony VAIO with Intel(R) Core(TM)2 Duo CPU >> P8400 2) It locks up Macbook Pro 8,1 with some 8-cores Intel >> >> Do you have any idea why it causes the lockup? Function causing >> problem is "set_ins_reg_val". I've created it as copy of >> get_ins_reg_val, it just sets values in struct pt_regs, instead of >> reading them). > > Sorry, I have no insight to that... does unmodified mmiotrace > work properly? Are you tracing the exact same kernel binary blob > on both machines? Maybe it's using some rare instruction > mmiotrace does not decode properly? Maybe with a rep prefix? > Do those CPUs have any differences in their registers or > struct pt_regs? > > I'm not even sure how "legal" it is to poke pt_regs there. :-/ Not modified MMIO tracing works great on this machine, I've grabbed dumps 10-20 times without a lock up or anything. I'm using different drivers on both machines, because Macbook Pro 8,1 has unique BCM4331 card that I can not buy and that is not available with PCI(e) slot. Is uses some vendor specific, PCIe compatible slot. Simple commenting out "set_ins_reg_val" work fine on this Macbook, PHY reads are tracked correctly. As for differences in struct pt_regs... yeah, I think that happens. I'm using x86 kernel, while on Macbook we use x86_64 as it's required to use 64bit driver in ndiswrapper. I can try to find out, which register we try to overwrite on Macbook. -- Rafał -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/