From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753860Ab0CIJMa (ORCPT ); Tue, 9 Mar 2010 04:12:30 -0500 Received: from hera.kernel.org ([140.211.167.34]:35101 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752854Ab0CIJM1 (ORCPT ); Tue, 9 Mar 2010 04:12:27 -0500 Message-ID: <4B9610E5.4080805@kernel.org> Date: Tue, 09 Mar 2010 18:12:05 +0900 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: Valdis.Kletnieks@vt.edu CC: Peter Zijlstra , Andrew Morton , Ingo Molnar , linux-kernel@vger.kernel.org Subject: [PATCH] percpu,lockdep: implement and use is_static_percpu_address() References: <24605.1268073053@localhost> <1268073831.4997.69.camel@laptop> <4B95AA4C.2030303@kernel.org> <4298.1268116039@localhost> <4B95EE4C.3020606@kernel.org> In-Reply-To: <4B95EE4C.3020606@kernel.org> X-Enigmail-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 09 Mar 2010 09:12:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org lockdep has custom code to check whether a pointer belongs to static percpu area which is somewhat broken. Implement proper is_static_percpu_address() in percpu and replace the custom code. Signed-off-by: Tejun Heo Cc: Ingo Molnar Cc: Peter Zijlstra --- This wasn't the cause this time but I'll queue the fix in percpu tree anyway. Thanks. include/linux/percpu.h | 7 +++++++ kernel/lockdep.c | 15 ++------------- mm/percpu.c | 26 ++++++++++++++++++++++++++ 3 files changed, 35 insertions(+), 13 deletions(-) diff --git a/include/linux/percpu.h b/include/linux/percpu.h index a93e5bf..1eca064 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -137,6 +137,7 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size, extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align); extern void __percpu *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void __percpu *__pdata); +extern bool is_static_percpu_address(unsigned long addr); extern phys_addr_t per_cpu_ptr_to_phys(void *addr); #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA @@ -163,6 +164,12 @@ static inline void free_percpu(void __percpu *p) kfree(p); } +/* can't distinguish from other static vars, always false */ +static inline bool is_static_percpu_address(unsigned long addr) +{ + return false; +} + static inline phys_addr_t per_cpu_ptr_to_phys(void *addr) { return __pa(addr); diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 0c30d04..4206f6f 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -582,9 +582,6 @@ static int static_obj(void *obj) unsigned long start = (unsigned long) &_stext, end = (unsigned long) &_end, addr = (unsigned long) obj; -#ifdef CONFIG_SMP - int i; -#endif /* * static variable? @@ -595,19 +592,11 @@ static int static_obj(void *obj) if (arch_is_kernel_data(addr)) return 1; -#ifdef CONFIG_SMP /* * percpu var? */ - for_each_possible_cpu(i) { - start = (unsigned long) &__per_cpu_start + per_cpu_offset(i); - end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM - + per_cpu_offset(i); - - if ((addr >= start) && (addr < end)) - return 1; - } -#endif + if (is_static_percpu_address(addr)) + return 1; /* * module var? diff --git a/mm/percpu.c b/mm/percpu.c index 768419d..ae4d058 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1304,6 +1304,32 @@ void free_percpu(void __percpu *ptr) EXPORT_SYMBOL_GPL(free_percpu); /** + * is_static_percpu_address - test whether address is from static percpu area + * @addr: address to test + * + * Test whether @addr belongs to static percpu area. Module static + * percpu areas allocated via __alloc_reserved_percpu() is not + * considered. Use is_module_address() for those. + * + * RETURNS: + * %true if @addr is from static percpu area, %false otherwise. + */ +bool is_static_percpu_address(unsigned long addr) +{ + const size_t static_size = __per_cpu_end - __per_cpu_start; + void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); + unsigned int cpu; + + for_each_possible_cpu(cpu) { + void *start = per_cpu_ptr(base, cpu); + + if ((void *)addr >= start && (void *)addr < start + static_size) + return true; + } + return false; +} + +/** * per_cpu_ptr_to_phys - convert translated percpu address to physical address * @addr: the address to be converted to physical address * -- 1.6.4.2