Return-path: Received: from perches-mx.perches.com ([206.117.179.246]:45333 "EHLO labridge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754634Ab2F3Osz (ORCPT ); Sat, 30 Jun 2012 10:48:55 -0400 Message-ID: <1341067733.10253.2.camel@joe2Laptop> (sfid-20120630_165403_445676_B07E81D8) Subject: Re: [RFC][PATCH 1/2] lib: printf: append support of '%*p[Mm][FR]' From: Joe Perches To: Andrew Morton Cc: Andy Shevchenko , proski@gnu.org, Andrei Emeltchenko , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sat, 30 Jun 2012 07:48:53 -0700 In-Reply-To: <20120629162649.f277177f.akpm@linux-foundation.org> References: <20110930115306.3bc105cb@mj> <1340985513-15655-1-git-send-email-andriy.shevchenko@linux.intel.com> <1340986086.6562.36.camel@joe2Laptop> <20120629162649.f277177f.akpm@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2012-06-29 at 16:26 -0700, Andrew Morton wrote: > On Fri, 29 Jun 2012 09:08:06 -0700 > Joe Perches wrote: > > > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > > [] > > > @@ -655,11 +655,12 @@ char *resource_string(char *buf, char *end, struct resource *res, > > > } > > > > > > static noinline_for_stack > > > -char *mac_address_string(char *buf, char *end, u8 *addr, > > > - struct printf_spec spec, const char *fmt) > > > +char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, > > > + const char *fmt) > > > { > > > - char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; > > > - char *p = mac_addr; > > > + char hex_str[64*3]; /* support up to 64 bytes to print */ > > > > Might be too much stack though. > > Yes, it's a bit marginal, as this new capability might be used in debug > or crash situations where we're deep into the stack. The average case > could be improved by using alloca()-style allocation. Or maybe support larger sizes with a smaller stack buffer and a while loop.