From owner-freebsd-hackers@FreeBSD.ORG Wed Apr 23 09:12:40 2008 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2F5A7106566C for ; Wed, 23 Apr 2008 09:12:40 +0000 (UTC) (envelope-from yanefbsd@gmail.com) Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.158]) by mx1.freebsd.org (Postfix) with ESMTP id A45F68FC12 for ; Wed, 23 Apr 2008 09:12:39 +0000 (UTC) (envelope-from yanefbsd@gmail.com) Received: by fg-out-1718.google.com with SMTP id 16so2748095fgg.35 for ; Wed, 23 Apr 2008 02:12:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; bh=lTKeAto29eUPCZUHtA0FXtvkJi3I4B+O9eTIb9IE4zo=; b=BhPIbq5T+uYllS9euvkoMXZp8rpU7GkZfiOZN4/YduK1ylPHJopiBRkKfneZIaJ+Ii00D27ksU1p9ezghcgmKAU/ssaZhXXnjod5qR+LJNbTb6ti6Qek/dvH35Mv39GyXYUaJkp5qkvTYjo9oAeURQf6tDcpH9BDRESbRkhglUM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=fhRVzuys0o14n4H6oIkQB6iCFiMAiZw9dZKgoNqPQNTMx8biYrzrdInLKDQmN9CmHPRof+G7MbULAPE8dXdyxc/diyG//MXZ15/2dq2cBbpz8Xcd9bbWHD2pRbVNOmuVOU70sJYIJuYAJ/MKNzrlO0xujorQsvAsWgdxc74kSj4= Received: by 10.86.59.2 with SMTP id h2mr2668840fga.78.1208941957637; Wed, 23 Apr 2008 02:12:37 -0700 (PDT) Received: by 10.86.26.8 with HTTP; Wed, 23 Apr 2008 02:12:37 -0700 (PDT) Message-ID: <7d6fde3d0804230212o6cef38fesb2e7d87848ed74b1@mail.gmail.com> Date: Wed, 23 Apr 2008 02:12:37 -0700 From: "Garrett Cooper" To: hackers@freebsd.org In-Reply-To: <7d6fde3d0804230211x4c6d1fa4v19118d6104c09f4@mail.gmail.com> MIME-Version: 1.0 References: <7d6fde3d0804222240j6b42b77yd86d8accb5a959fa@mail.gmail.com> <20080423025048.6b51a580@bhuda.mired.org> <7d6fde3d0804230211x4c6d1fa4v19118d6104c09f4@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Subject: Re: strdup(NULL) supposed to create SIGSEGV? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Apr 2008 09:12:40 -0000 On Wed, Apr 23, 2008 at 2:11 AM, Garrett Cooper wrote: > On Tue, Apr 22, 2008 at 11:50 PM, Mike Meyer wrote: > > > On Tue, 22 Apr 2008 22:40:21 -0700 > > "Garrett Cooper" wrote: > > > > > Hi all, > > > I made an oops in a program, which uncovered "feature" in > > strdup(2) > > > that I wasn't aware of before. So I was wondering, is strdup(pointer = > > NULL) > > > supposed to segfault should this just return NULL and set errno? > > > > Yes, it's supposed to segfault. Check out what, say, strcpy does if > > you ask it to copy a NULL pointer. And this is an improvement from the > > bad old days, when they would happily walk through memory starting at > > 0..... > > > > Besides, errno is used to signal errors from system calls. strdup > > isn't a system call, it's a library function (says so at the top of > > the man page). > > > > > Good news is that Linux does the same thing (yay?), so at least > > FreeBSD > > > isn't alone.. > > > > Do you have examples of systems where strdup doesn't behave this way? > > > > > > No, I don't, but then again I just noticed this. > -Garrett > (and thanks for clarifying about errno; didn't realize that) -Garrett