From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 01 Mar 2012 21:47:56 +0100 (CET) Received: from terminus.zytor.com ([198.137.202.10]:44063 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1903701Ab2CAUrw (ORCPT ); Thu, 1 Mar 2012 21:47:52 +0100 Received: from tazenda.hos.anvin.org ([IPv6:2001:470:861f::feed:face:f00d]) (authenticated bits=0) by mail.zytor.com (8.14.5/8.14.5) with ESMTP id q21Kl373015685 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=OK); Thu, 1 Mar 2012 12:47:04 -0800 Message-ID: <4F4FE041.1000507@zytor.com> Date: Thu, 01 Mar 2012 12:46:57 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120209 Thunderbird/10.0.1 MIME-Version: 1.0 To: Veli-Pekka Peltola CC: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, Russell King , Thomas Gleixner , Ingo Molnar , x86@kernel.org Subject: Re: [PATCH] mm: module_alloc: check if size is 0 References: <1330631119-10059-1-git-send-email-veli-pekka.peltola@bluegiga.com> In-Reply-To: <1330631119-10059-1-git-send-email-veli-pekka.peltola@bluegiga.com> X-Enigmail-Version: 1.3.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-archive-position: 32592 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: hpa@zytor.com Precedence: bulk X-list: linux-mips Return-Path: On 03/01/2012 11:45 AM, Veli-Pekka Peltola wrote: > diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c > index 1e9be5d..d44d212 100644 > --- a/arch/arm/kernel/module.c > +++ b/arch/arm/kernel/module.c > @@ -39,8 +39,8 @@ > #ifdef CONFIG_MMU > void *module_alloc(unsigned long size) > { > - return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, > - GFP_KERNEL, PAGE_KERNEL_EXEC, -1, > + return size == 0 ? NULL : __vmalloc_node_range(size, 1, MODULES_VADDR, > + MODULES_END, GFP_KERNEL, PAGE_KERNEL_EXEC, -1, > __builtin_return_address(0)); > } > #endif > diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c > index a5066b1..cd768e9 100644 > --- a/arch/mips/kernel/module.c > +++ b/arch/mips/kernel/module.c > @@ -47,8 +47,8 @@ static DEFINE_SPINLOCK(dbe_lock); > #ifdef MODULE_START > void *module_alloc(unsigned long size) > { > - return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END, > - GFP_KERNEL, PAGE_KERNEL, -1, > + return size == 0 ? NULL : __vmalloc_node_range(size, 1, MODULE_START, > + MODULE_END, GFP_KERNEL, PAGE_KERNEL, -1, > __builtin_return_address(0)); > } > #endif > diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c > index 925179f..bff6118 100644 > --- a/arch/x86/kernel/module.c > +++ b/arch/x86/kernel/module.c > @@ -38,7 +38,7 @@ > > void *module_alloc(unsigned long size) > { > - if (PAGE_ALIGN(size) > MODULES_LEN) > + if (size == 0 || PAGE_ALIGN(size) > MODULES_LEN) > return NULL; > return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, > GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC, Looks good stylistically but really awkward technically. I would like to suggest using the idiom: if (!size) return NULL; ... consistently; combined with the PAGE_ALIGN() clause for x86 is fine too. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. From mboxrd@z Thu Jan 1 00:00:00 1970 From: hpa@zytor.com (H. Peter Anvin) Date: Thu, 01 Mar 2012 12:46:57 -0800 Subject: [PATCH] mm: module_alloc: check if size is 0 In-Reply-To: <1330631119-10059-1-git-send-email-veli-pekka.peltola@bluegiga.com> References: <1330631119-10059-1-git-send-email-veli-pekka.peltola@bluegiga.com> Message-ID: <4F4FE041.1000507@zytor.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/01/2012 11:45 AM, Veli-Pekka Peltola wrote: > diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c > index 1e9be5d..d44d212 100644 > --- a/arch/arm/kernel/module.c > +++ b/arch/arm/kernel/module.c > @@ -39,8 +39,8 @@ > #ifdef CONFIG_MMU > void *module_alloc(unsigned long size) > { > - return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, > - GFP_KERNEL, PAGE_KERNEL_EXEC, -1, > + return size == 0 ? NULL : __vmalloc_node_range(size, 1, MODULES_VADDR, > + MODULES_END, GFP_KERNEL, PAGE_KERNEL_EXEC, -1, > __builtin_return_address(0)); > } > #endif > diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c > index a5066b1..cd768e9 100644 > --- a/arch/mips/kernel/module.c > +++ b/arch/mips/kernel/module.c > @@ -47,8 +47,8 @@ static DEFINE_SPINLOCK(dbe_lock); > #ifdef MODULE_START > void *module_alloc(unsigned long size) > { > - return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END, > - GFP_KERNEL, PAGE_KERNEL, -1, > + return size == 0 ? NULL : __vmalloc_node_range(size, 1, MODULE_START, > + MODULE_END, GFP_KERNEL, PAGE_KERNEL, -1, > __builtin_return_address(0)); > } > #endif > diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c > index 925179f..bff6118 100644 > --- a/arch/x86/kernel/module.c > +++ b/arch/x86/kernel/module.c > @@ -38,7 +38,7 @@ > > void *module_alloc(unsigned long size) > { > - if (PAGE_ALIGN(size) > MODULES_LEN) > + if (size == 0 || PAGE_ALIGN(size) > MODULES_LEN) > return NULL; > return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, > GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC, Looks good stylistically but really awkward technically. I would like to suggest using the idiom: if (!size) return NULL; ... consistently; combined with the PAGE_ALIGN() clause for x86 is fine too. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.