From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751844AbdFHU7b (ORCPT ); Thu, 8 Jun 2017 16:59:31 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:36713 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751772AbdFHU73 (ORCPT ); Thu, 8 Jun 2017 16:59:29 -0400 From: Rasmus Villemoes To: Andy Shevchenko Cc: Rasmus Villemoes , Greg Kroah-Hartman , Andrew Morton , linux-kernel@vger.kernel.org, Alessandro Zummo , Alexandre Belloni , linux-rtc@vger.kernel.org Subject: Re: [PATCH v1 01/25] lib/vsprintf: Remove useless NULL checks Organization: D03 References: <20170608134811.60786-1-andriy.shevchenko@linux.intel.com> <20170608134811.60786-2-andriy.shevchenko@linux.intel.com> X-Hashcash: 1:20:170608:andriy.shevchenko@linux.intel.com::93YQ1ZWJ7jTcYaxR:00000000000000000000000000000kqk X-Hashcash: 1:20:170608:linux-rtc@vger.kernel.org::74oYjAFSavaoEP+S:0000000000000000000000000000000000000eIR X-Hashcash: 1:20:170608:akpm@linux-foundation.org::rIGw33W2U+3GHdhP:0000000000000000000000000000000000001gpb X-Hashcash: 1:20:170608:linux-kernel@vger.kernel.org::QKXixSxwlLroejqr:0000000000000000000000000000000003MPU X-Hashcash: 1:20:170608:alexandre.belloni@free-electrons.com::qs8EG0E6WKdA5ZTy:00000000000000000000000004uWV X-Hashcash: 1:20:170608:a.zummo@towertech.it::EtsaspqItYcBnOsx:000000000000000000000000000000000000000004kXj X-Hashcash: 1:20:170608:rasmus.villemoes@prevas.dk::Bs2bSDJaV4kaFvBk:000000000000000000000000000000000009QKf X-Hashcash: 1:20:170608:gregkh@linuxfoundation.org::L/06XA+Woz4gyWmu:00000000000000000000000000000000000D5st Date: Thu, 08 Jun 2017 22:59:26 +0200 In-Reply-To: <20170608134811.60786-2-andriy.shevchenko@linux.intel.com> (Andy Shevchenko's message of "Thu, 8 Jun 2017 16:47:47 +0300") Message-ID: <87shjakxg1.fsf@rasmusvillemoes.dk> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 08 2017, Andy Shevchenko wrote: > The pointer can't be NULL since it's first what has been done in the > pointer(). > > Remove useless checks. > > Note when we print clock name or rate it is safe in case !CONFIG_HAVE_CLK. > > Signed-off-by: Andy Shevchenko > --- > lib/vsprintf.c | 11 ----------- > 1 file changed, 11 deletions(-) > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > index 9f16406288c0..031c2cc5c1c0 100644 > --- a/lib/vsprintf.c > +++ b/lib/vsprintf.c > @@ -811,10 +811,6 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, > /* nothing to print */ > return buf; > > - if (ZERO_OR_NULL_PTR(addr)) > - /* NULL pointer */ > - return string(buf, end, NULL, spec); > - > switch (fmt[1]) { > case 'C': > separator = ':'; > @@ -1253,10 +1249,6 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, > if (spec.field_width == 0) > return buf; /* nothing to print */ > > - if (ZERO_OR_NULL_PTR(addr)) > - return string(buf, end, NULL, spec); /* NULL pointer */ > - > - Well, ZERO_OR_NULL_PTR checks for a little more than !addr, but I suppose that if anyone passes the result from kmalloc(0) to %ph, they'd better also pass 0 as the size, so the .field_width tests should be sufficient. > do { > switch (fmt[count++]) { > case 'a': > @@ -1391,9 +1383,6 @@ static noinline_for_stack > char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, > const char *fmt) > { > - if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk) > - return string(buf, end, NULL, spec); > - Well, it may be safe, but removing the IS_ENABLED(CONFIG_HAVE_CLK) check means that clock() becomes a much bigger function when !IS_ENABLED(CONFIG_HAVE_CLK). You're right that the !clk check is pointless.