From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756343Ab3EVOcV (ORCPT ); Wed, 22 May 2013 10:32:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:20278 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756249Ab3EVObq (ORCPT ); Wed, 22 May 2013 10:31:46 -0400 Date: Wed, 22 May 2013 17:30:00 +0300 From: "Michael S. Tsirkin" To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , David Howells , Hirokazu Takata , Michal Simek , Koichi Yasutake , Benjamin Herrenschmidt , Paul Mackerras , Chris Metcalf , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org, microblaze-uclinux@itee.uq.edu.au, linux-am33-list@redhat.com, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org Subject: Re: [PATCH v2 07/10] powerpc: uaccess s/might_sleep/might_fault/ Message-ID: <20130522143000.GA21886@redhat.com> References: <2aa6c3da21a28120126732b5e0b4ecd6cba8ca3b.1368702323.git.mst@redhat.com> <201305221559.01806.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201305221559.01806.arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 22, 2013 at 03:59:01PM +0200, Arnd Bergmann wrote: > On Thursday 16 May 2013, Michael S. Tsirkin wrote: > > @@ -178,7 +178,7 @@ do { \ > > long __pu_err; \ > > __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ > > if (!is_kernel_addr((unsigned long)__pu_addr)) \ > > - might_sleep(); \ > > + might_fault(); \ > > __chk_user_ptr(ptr); \ > > __put_user_size((x), __pu_addr, (size), __pu_err); \ > > __pu_err; \ > > > > Another observation: > > if (!is_kernel_addr((unsigned long)__pu_addr)) > might_sleep(); > > is almost the same as > > might_fault(); > > except that it does not call might_lock_read(). > > The version above may have been put there intentionally and correctly, but > if you want to replace it with might_fault(), you should remove the > "if ()" condition. > > Arnd Good point, thanks. I think I'll do it in a separate patch on top, just to make sure bisect does not result in a revision that produces false positive warnings. -- MST From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v2 07/10] powerpc: uaccess s/might_sleep/might_fault/ Date: Wed, 22 May 2013 17:30:00 +0300 Message-ID: <20130522143000.GA21886@redhat.com> References: <2aa6c3da21a28120126732b5e0b4ecd6cba8ca3b.1368702323.git.mst@redhat.com> <201305221559.01806.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <201305221559.01806.arnd@arndb.de> Sender: owner-linux-mm@kvack.org To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , David Howells , Hirokazu Takata , Michal Simek , Koichi Yasutake , Benjamin Herrenschmidt , Paul Mackerras , Chris Metcalf , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org, microblaze-uclinux@itee.uq.edu.au, linux-am33-list@redhat.com, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, linux-mm@kvack.o List-Id: linux-arch.vger.kernel.org On Wed, May 22, 2013 at 03:59:01PM +0200, Arnd Bergmann wrote: > On Thursday 16 May 2013, Michael S. Tsirkin wrote: > > @@ -178,7 +178,7 @@ do { \ > > long __pu_err; \ > > __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ > > if (!is_kernel_addr((unsigned long)__pu_addr)) \ > > - might_sleep(); \ > > + might_fault(); \ > > __chk_user_ptr(ptr); \ > > __put_user_size((x), __pu_addr, (size), __pu_err); \ > > __pu_err; \ > > > > Another observation: > > if (!is_kernel_addr((unsigned long)__pu_addr)) > might_sleep(); > > is almost the same as > > might_fault(); > > except that it does not call might_lock_read(). > > The version above may have been put there intentionally and correctly, but > if you want to replace it with might_fault(), you should remove the > "if ()" condition. > > Arnd Good point, thanks. I think I'll do it in a separate patch on top, just to make sure bisect does not result in a revision that produces false positive warnings. -- MST -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx160.postini.com [74.125.245.160]) by kanga.kvack.org (Postfix) with SMTP id 4B9066B00CB for ; Wed, 22 May 2013 10:30:52 -0400 (EDT) Date: Wed, 22 May 2013 17:30:00 +0300 From: "Michael S. Tsirkin" Subject: Re: [PATCH v2 07/10] powerpc: uaccess s/might_sleep/might_fault/ Message-ID: <20130522143000.GA21886@redhat.com> References: <2aa6c3da21a28120126732b5e0b4ecd6cba8ca3b.1368702323.git.mst@redhat.com> <201305221559.01806.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201305221559.01806.arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , David Howells , Hirokazu Takata , Michal Simek , Koichi Yasutake , Benjamin Herrenschmidt , Paul Mackerras , Chris Metcalf , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org, microblaze-uclinux@itee.uq.edu.au, linux-am33-list@redhat.com, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org On Wed, May 22, 2013 at 03:59:01PM +0200, Arnd Bergmann wrote: > On Thursday 16 May 2013, Michael S. Tsirkin wrote: > > @@ -178,7 +178,7 @@ do { \ > > long __pu_err; \ > > __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ > > if (!is_kernel_addr((unsigned long)__pu_addr)) \ > > - might_sleep(); \ > > + might_fault(); \ > > __chk_user_ptr(ptr); \ > > __put_user_size((x), __pu_addr, (size), __pu_err); \ > > __pu_err; \ > > > > Another observation: > > if (!is_kernel_addr((unsigned long)__pu_addr)) > might_sleep(); > > is almost the same as > > might_fault(); > > except that it does not call might_lock_read(). > > The version above may have been put there intentionally and correctly, but > if you want to replace it with might_fault(), you should remove the > "if ()" condition. > > Arnd Good point, thanks. I think I'll do it in a separate patch on top, just to make sure bisect does not result in a revision that produces false positive warnings. -- MST -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by ozlabs.org (Postfix) with ESMTP id 7F01D2C008A for ; Thu, 23 May 2013 00:31:30 +1000 (EST) Date: Wed, 22 May 2013 17:30:00 +0300 From: "Michael S. Tsirkin" To: Arnd Bergmann Subject: Re: [PATCH v2 07/10] powerpc: uaccess s/might_sleep/might_fault/ Message-ID: <20130522143000.GA21886@redhat.com> References: <2aa6c3da21a28120126732b5e0b4ecd6cba8ca3b.1368702323.git.mst@redhat.com> <201305221559.01806.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <201305221559.01806.arnd@arndb.de> Cc: linux-m32r-ja@ml.linux-m32r.org, kvm@vger.kernel.org, Peter Zijlstra , Catalin Marinas , Will Deacon , David Howells , linux-mm@kvack.org, Paul Mackerras , "H. Peter Anvin" , linux-arch@vger.kernel.org, linux-am33-list@redhat.com, Hirokazu Takata , x86@kernel.org, Ingo Molnar , microblaze-uclinux@itee.uq.edu.au, Chris Metcalf , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Michal Simek , linux-m32r@ml.linux-m32r.org, linux-kernel@vger.kernel.org, Koichi Yasutake , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, May 22, 2013 at 03:59:01PM +0200, Arnd Bergmann wrote: > On Thursday 16 May 2013, Michael S. Tsirkin wrote: > > @@ -178,7 +178,7 @@ do { \ > > long __pu_err; \ > > __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ > > if (!is_kernel_addr((unsigned long)__pu_addr)) \ > > - might_sleep(); \ > > + might_fault(); \ > > __chk_user_ptr(ptr); \ > > __put_user_size((x), __pu_addr, (size), __pu_err); \ > > __pu_err; \ > > > > Another observation: > > if (!is_kernel_addr((unsigned long)__pu_addr)) > might_sleep(); > > is almost the same as > > might_fault(); > > except that it does not call might_lock_read(). > > The version above may have been put there intentionally and correctly, but > if you want to replace it with might_fault(), you should remove the > "if ()" condition. > > Arnd Good point, thanks. I think I'll do it in a separate patch on top, just to make sure bisect does not result in a revision that produces false positive warnings. -- MST From mboxrd@z Thu Jan 1 00:00:00 1970 From: mst@redhat.com (Michael S. Tsirkin) Date: Wed, 22 May 2013 17:30:00 +0300 Subject: [PATCH v2 07/10] powerpc: uaccess s/might_sleep/might_fault/ In-Reply-To: <201305221559.01806.arnd@arndb.de> References: <2aa6c3da21a28120126732b5e0b4ecd6cba8ca3b.1368702323.git.mst@redhat.com> <201305221559.01806.arnd@arndb.de> Message-ID: <20130522143000.GA21886@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, May 22, 2013 at 03:59:01PM +0200, Arnd Bergmann wrote: > On Thursday 16 May 2013, Michael S. Tsirkin wrote: > > @@ -178,7 +178,7 @@ do { \ > > long __pu_err; \ > > __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ > > if (!is_kernel_addr((unsigned long)__pu_addr)) \ > > - might_sleep(); \ > > + might_fault(); \ > > __chk_user_ptr(ptr); \ > > __put_user_size((x), __pu_addr, (size), __pu_err); \ > > __pu_err; \ > > > > Another observation: > > if (!is_kernel_addr((unsigned long)__pu_addr)) > might_sleep(); > > is almost the same as > > might_fault(); > > except that it does not call might_lock_read(). > > The version above may have been put there intentionally and correctly, but > if you want to replace it with might_fault(), you should remove the > "if ()" condition. > > Arnd Good point, thanks. I think I'll do it in a separate patch on top, just to make sure bisect does not result in a revision that produces false positive warnings. -- MST