From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f52.google.com (mail-pb0-f52.google.com [209.85.160.52]) by kanga.kvack.org (Postfix) with ESMTP id 3C8A06B0036 for ; Thu, 30 Jan 2014 16:45:49 -0500 (EST) Received: by mail-pb0-f52.google.com with SMTP id jt11so3645827pbb.39 for ; Thu, 30 Jan 2014 13:45:48 -0800 (PST) Received: from mail-pb0-f50.google.com (mail-pb0-f50.google.com [209.85.160.50]) by mx.google.com with ESMTPS id ln7si7950874pab.207.2014.01.30.13.45.48 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 30 Jan 2014 13:45:48 -0800 (PST) Received: by mail-pb0-f50.google.com with SMTP id rq2so3651901pbb.9 for ; Thu, 30 Jan 2014 13:45:48 -0800 (PST) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable From: Sebastian Capella In-Reply-To: <20140130132251.4f662aeddc09d8410dee4490@linux-foundation.org> References: <1391116318-17253-1-git-send-email-sebastian.capella@linaro.org> <1391116318-17253-2-git-send-email-sebastian.capella@linaro.org> <20140130132251.4f662aeddc09d8410dee4490@linux-foundation.org> Message-ID: <20140130214545.18296.69349@capellas-linux> Subject: Re: [PATCH v5 1/2] mm: add kstrimdup function Date: Thu, 30 Jan 2014 13:45:45 -0800 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, Joe Perches , Mikulas Patocka , Michel Lespinasse , Shaohua Li , Jerome Marchand , Joonsoo Kim Quoting Andrew Morton (2014-01-30 13:22:51) > On Thu, 30 Jan 2014 13:11:57 -0800 Sebastian Capella wrote: > > +char *kstrimdup(const char *s, gfp_t gfp) > > +{ > > + char *buf; > > + char *begin =3D skip_spaces(s); > > + size_t len =3D strlen(begin); > > + > > + while (len > 1 && isspace(begin[len - 1])) > > + len--; > = > That's off-by-one isn't it? kstrimdup(" ") should return "", not " ". > = > > + buf =3D kmalloc_track_caller(len + 1, gfp); > > + if (!buf) > > + return NULL; > > + > > + memcpy(buf, begin, len); > > + buf[len] =3D '\0'; > > + > > + return buf; > > +} Hi Andrew, I think this is a little tricky. For an empty string, the function relies on skip_spaces to point begin at the \0'. Alternately, if we don't have an empty string, we know we have at least 1 non-space, non-null character at begin[0], and there's no need to check it, so the loop stops at [1]. If there's a space at 1, we just put the '\0' there. We could check at [0], but I think its already been checked by skip_spaces. I'll add a comment above the while for that Thanks, Sebastian -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org