From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932445AbeCLPRz (ORCPT ); Mon, 12 Mar 2018 11:17:55 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:34340 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751502AbeCLPRy (ORCPT ); Mon, 12 Mar 2018 11:17:54 -0400 X-Google-Smtp-Source: AG47ELvZWrWlnBj/PK0aY1vu2H+7OloNcuEI2nNsOKpROAIcZ2WFJZam91DGIrIoprlVy5RJmev8opPk2c5tr+xXdSg= MIME-Version: 1.0 In-Reply-To: <201803122219.vHl3IwRo%fengguang.wu@intel.com> References: <201803122219.vHl3IwRo%fengguang.wu@intel.com> From: Dmitry Vyukov Date: Mon, 12 Mar 2018 18:17:32 +0300 Message-ID: Subject: Re: [tip:locking/core 9/11] include/asm-generic/atomic-instrumented.h:288:24: sparse: cast truncates bits from constant value (100 becomes 0) To: kbuild test robot Cc: kbuild-all@01.org, LKML , tipbuild@zytor.com, Ingo Molnar Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 12, 2018 at 5:52 PM, kbuild test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core > head: ac605bee0bfab40fd5d11964705e907d2d5a32de > commit: 8bf705d130396e69c04cd8e6e010244ad2ce71f4 [9/11] locking/atomic/x86: Switch atomic.h to use atomic-instrumented.h > reproduce: > # apt-get install sparse > git checkout 8bf705d130396e69c04cd8e6e010244ad2ce71f4 > make ARCH=x86_64 allmodconfig > make C=1 CF=-D__CHECK_ENDIAN__ > > > sparse warnings: (new ones prefixed by >>) > > kernel/locking/qspinlock.c:418:22: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *prev @@ got struct struct mcs_spinlock *prev @@ > kernel/locking/qspinlock.c:418:22: expected struct mcs_spinlock *prev > kernel/locking/qspinlock.c:418:22: got struct mcs_spinlock [pure] * > kernel/locking/qspinlock_paravirt.h:519:1: sparse: symbol '__pv_queued_spin_unlock_slowpath' was not declared. Should it be static? > kernel/locking/qspinlock.c:418:22: sparse: incorrect type in assignment (different modifiers) @@ expected struct mcs_spinlock *prev @@ got struct struct mcs_spinlock *prev @@ > kernel/locking/qspinlock.c:418:22: expected struct mcs_spinlock *prev > kernel/locking/qspinlock.c:418:22: got struct mcs_spinlock [pure] * >>> include/asm-generic/atomic-instrumented.h:288:24: sparse: cast truncates bits from constant value (100 becomes 0) > > vim +288 include/asm-generic/atomic-instrumented.h > > b06ed71a6 Dmitry Vyukov 2018-01-29 282 > b06ed71a6 Dmitry Vyukov 2018-01-29 283 static __always_inline unsigned long > b06ed71a6 Dmitry Vyukov 2018-01-29 284 cmpxchg_size(volatile void *ptr, unsigned long old, unsigned long new, int size) > b06ed71a6 Dmitry Vyukov 2018-01-29 285 { > b06ed71a6 Dmitry Vyukov 2018-01-29 286 switch (size) { > b06ed71a6 Dmitry Vyukov 2018-01-29 287 case 1: > b06ed71a6 Dmitry Vyukov 2018-01-29 @288 return arch_cmpxchg((u8 *)ptr, (u8)old, (u8)new); > b06ed71a6 Dmitry Vyukov 2018-01-29 289 case 2: > b06ed71a6 Dmitry Vyukov 2018-01-29 290 return arch_cmpxchg((u16 *)ptr, (u16)old, (u16)new); > b06ed71a6 Dmitry Vyukov 2018-01-29 291 case 4: > b06ed71a6 Dmitry Vyukov 2018-01-29 292 return arch_cmpxchg((u32 *)ptr, (u32)old, (u32)new); > b06ed71a6 Dmitry Vyukov 2018-01-29 293 case 8: > b06ed71a6 Dmitry Vyukov 2018-01-29 294 BUILD_BUG_ON(sizeof(unsigned long) != 8); > b06ed71a6 Dmitry Vyukov 2018-01-29 295 return arch_cmpxchg((u64 *)ptr, (u64)old, (u64)new); > b06ed71a6 Dmitry Vyukov 2018-01-29 296 } > b06ed71a6 Dmitry Vyukov 2018-01-29 297 BUILD_BUG(); > b06ed71a6 Dmitry Vyukov 2018-01-29 298 return 0; > b06ed71a6 Dmitry Vyukov 2018-01-29 299 } > b06ed71a6 Dmitry Vyukov 2018-01-29 300 > > :::::: The code at line 288 was first introduced by commit > :::::: b06ed71a624ba088a3e3e3ac7d4185f48c7c1660 locking/atomic, asm-generic: Add asm-generic/atomic-instrumented.h > > :::::: TO: Dmitry Vyukov > :::::: CC: Ingo Molnar I will take a look tomorrow.