Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57395 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752273Ab2F2X0v (ORCPT ); Fri, 29 Jun 2012 19:26:51 -0400 Date: Fri, 29 Jun 2012 16:26:49 -0700 From: Andrew Morton To: Joe Perches Cc: Andy Shevchenko , proski@gnu.org, Andrei Emeltchenko , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 1/2] lib: printf: append support of '%*p[Mm][FR]' Message-Id: <20120629162649.f277177f.akpm@linux-foundation.org> (sfid-20120630_012709_850081_4127ACF5) In-Reply-To: <1340986086.6562.36.camel@joe2Laptop> References: <20110930115306.3bc105cb@mj> <1340985513-15655-1-git-send-email-andriy.shevchenko@linux.intel.com> <1340986086.6562.36.camel@joe2Laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: 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. Documentation/printk-formats.txt would need to be updated please. Also the big comment over vsnprintf().