From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61591C433C1 for ; Wed, 24 Mar 2021 17:21:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 222BB61A1C for ; Wed, 24 Mar 2021 17:21:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236526AbhCXRVA (ORCPT ); Wed, 24 Mar 2021 13:21:00 -0400 Received: from smtprelay0115.hostedemail.com ([216.40.44.115]:45432 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S237087AbhCXRU3 (ORCPT ); Wed, 24 Mar 2021 13:20:29 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay04.hostedemail.com (Postfix) with ESMTP id 126B118159034; Wed, 24 Mar 2021 17:20:28 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: blade66_5814dea2777c X-Filterd-Recvd-Size: 5314 Received: from [192.168.1.159] (unknown [47.151.137.21]) (Authenticated sender: joe@perches.com) by omf08.hostedemail.com (Postfix) with ESMTPA; Wed, 24 Mar 2021 17:20:24 +0000 (UTC) Message-ID: <3252fd83141aa9e0e6001acee1dd98e87c676b9a.camel@perches.com> Subject: [RFC patch] vsprintf: Allow %pe to print non PTR_ERR %pe uses as decimal From: Joe Perches To: Arnd Bergmann , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes Cc: Philipp Zabel , David Airlie , Daniel Vetter , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Marco Felsch , Laurent Pinchart , Liu Ying , dri-devel , Linux ARM , Linux Kernel Mailing List Date: Wed, 24 Mar 2021 10:20:23 -0700 In-Reply-To: <810d36184b9fa2880d3ba7738a8f182e27f5107b.camel@perches.com> References: <20210324121832.3714570-1-arnd@kernel.org> <810d36184b9fa2880d3ba7738a8f182e27f5107b.camel@perches.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2021-03-24 at 09:52 -0700, Joe Perches wrote: > On Wed, 2021-03-24 at 17:42 +0100, Arnd Bergmann wrote: > > On Wed, Mar 24, 2021 at 3:20 PM Joe Perches wrote: > [] > > > > diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c > > > [] > > > > @@ -197,6 +197,12 @@ static void imx_ldb_encoder_enable(struct drm_encoder *encoder) > > > >       int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN; > > > >       int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder); > > > > > > > > + if (mux < 0 || mux >= ARRAY_SIZE(ldb->clk_sel)) { > > > > + dev_warn(ldb->dev, "%s: invalid mux %d\n", > > > > + __func__, ERR_PTR(mux)); > > > > > > This does not compile without warnings. > > > > > > drivers/gpu/drm/imx/imx-ldb.c: In function ‘imx_ldb_encoder_enable’: > > > drivers/gpu/drm/imx/imx-ldb.c:201:22: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘void *’ [-Wformat=] > > >   201 | dev_warn(ldb->dev, "%s: invalid mux %d\n", > > >       | ^~~~~~~~~~~~~~~~~~~~~~ > > > > > > If you want to use ERR_PTR, the %d should be %pe as ERR_PTR > > > is converting an int a void * to decode the error type and > > > emit it as a string. > > > > Sorry about that. > > > > I decided against using ERR_PTR() in order to also check for > > positive array overflow, but the version I tested was different from > > the version I sent. > > > > v3 coming. > > Thanks. No worries. > > Up to you, vsprintf would emit the positive mux as a funky hashed > hex value by default if you use ERR_PTR with mux > ARRAY_SIZE so > perhaps %d without the ERR_PTR use makes the most sense. > > Maybe it's better to output non PTR_ERR %pe uses as decimal so this sort of code would work. --- lib/vsprintf.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 3600db686fa4..debdd1c62038 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -619,19 +619,23 @@ static char *string_nocheck(char *buf, char *end, const char *s, return widen_string(buf, len, end, spec); } -static char *err_ptr(char *buf, char *end, void *ptr, - struct printf_spec spec) +static noinline_for_stack +char *err_ptr(char *buf, char *end, void *ptr, struct printf_spec spec) { int err = PTR_ERR(ptr); - const char *sym = errname(err); - if (sym) - return string_nocheck(buf, end, sym, spec); + if (IS_ERR(ptr)) { + const char *sym = errname(err); + + if (sym) + return string_nocheck(buf, end, sym, spec); + } /* - * Somebody passed ERR_PTR(-1234) or some other non-existing - * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to - * printing it as its decimal representation. + * Somebody passed ERR_PTR(-1234) or some other non-existing -E + * or perhaps CONFIG_SYMBOLIC_ERRNAME=n + * or perhaps a positive number like an array index + * Fall back to printing it as its decimal representation. */ spec.flags |= SIGN; spec.base = 10; @@ -2407,9 +2411,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, case 'x': return pointer_string(buf, end, ptr, spec); case 'e': - /* %pe with a non-ERR_PTR gets treated as plain %p */ - if (!IS_ERR(ptr)) - break; + /* %pe with a non-ERR_PTR(ptr) gets treated as %ld */ return err_ptr(buf, end, ptr, spec); case 'u': case 'k': ---