From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from sabertooth02.qualcomm.com ([65.197.215.38]:61413 "EHLO sabertooth02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753133Ab2L0Pzl (ORCPT ); Thu, 27 Dec 2012 10:55:41 -0500 Cc: , From: Kalle Valo To: Johannes Berg Subject: Re: [PATCH 5/7] ath6kl: convert ath6kl_info/err/warn macros to real functions References: <20121227114156.27069.30223.stgit@localhost6.localdomain6> <20121227114447.27069.54329.stgit@localhost6.localdomain6> <1356610754.15149.11.camel@jlt4.sipsolutions.net> <871uebfqe3.fsf@qca.qualcomm.com> Date: Thu, 27 Dec 2012 17:55:46 +0200 In-Reply-To: <871uebfqe3.fsf@qca.qualcomm.com> (Kalle Valo's message of "Thu, 27 Dec 2012 17:47:48 +0200") Message-ID: <87wqw3ebgd.fsf@qca.qualcomm.com> (sfid-20121227_165555_544593_D504BFD2) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-wireless-owner@vger.kernel.org List-ID: Kalle Valo writes: >> Note that by inserting the tracing here later, you're relying on the >> fact that "%pV" does va_copy(). This isn't true in all kernel versions, >> I think there's on version or so where %pV is supported but didn't >> va_copy(). That may lead to problems (I don't remember what kind) here. >> >> This is relevant for compat only, I think I carry a patch there to add >> va_copy() into the tracing or something. > > Compat-drivers has 55-iwlwifi-msg-trace-fix.patch which says: > > "In recent kernels, %pV will copy the va_list before using it. > This isn't true for all kernels, so copy the va_list for use > by the dev_*() functions, otherwise the kernel will crash if > the message is printed and traced." > > I take it that the problem happens when the message is both printed and > traced at the same time. So ath6kl will need a similar patch as well. For the archives: I'm guessing this is the commit which fixed the issue: commit 5756b76e4db643d8f75174a9a50038523d4b9e32 Author: Jan Beulich Date: Mon Mar 5 16:49:24 2012 +0000 vsprintf: make %pV handling compatible with kasprintf() And git-describe tells me that it was introduced in 3.3-rc7, so quite recent. Kalle