From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753473Ab0INDJr (ORCPT ); Mon, 13 Sep 2010 23:09:47 -0400 Received: from mx4-phx2.redhat.com ([209.132.183.25]:42764 "EHLO mx02.colomx.prod.int.phx2.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752094Ab0INDJq (ORCPT ); Mon, 13 Sep 2010 23:09:46 -0400 Date: Mon, 13 Sep 2010 23:09:39 -0400 (EDT) From: CAI Qian To: linux-kernel Cc: Avi Kivity , Marcelo Tosatti , tj@kernel.org, dhowells@redhat.com, graff.yang@gmail.com, sonic.adi@gmail.com, kexec Message-ID: <149379123.860951284433779554.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> Subject: kvm kdump regression MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.5.5.72] X-Mailer: Zimbra 5.0.21_GA_3150.RHEL4_64 (ZimbraWebClient - FF3.0 (Linux)/5.0.21_GA_3150.RHEL4_64) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit introduced a regression that an empty vmcore was generated on a kvm guest. ioremap: invalid physical address db74000000000000 ------------[ cut here ]------------ WARNING: at arch/x86/mm/ioremap.c:83 __ioremap_caller+0x307/0x380() Hardware name: KVM Modules linked in: Pid: 1, comm: swapper Not tainted 2.6.36-rc2-mm1+ #2 Call Trace: [] warn_slowpath_common+0x7f/0xc0 [] ? copy_oldmem_page+0x4e/0xc0 [] warn_slowpath_null+0x1a/0x20 [] __ioremap_caller+0x307/0x380 [] ioremap_nocache+0x17/0x20 [] copy_oldmem_page+0x4e/0xc0 [] read_from_oldmem+0x7a/0xb0 [] merge_note_headers_elf64.clone.1+0x6c/0x21f [] ? copy_oldmem_page+0x8e/0xc0 [] ? read_from_oldmem+0x7a/0xb0 [] vmcore_init+0x19d/0x396 [] ? vmcore_init+0x0/0x396 [] do_one_initcall+0x43/0x190 [] kernel_init+0x2a0/0x330 [] kernel_thread_helper+0x4/0x10 [] ? kernel_init+0x0/0x330 [] ? kernel_thread_helper+0x0/0x10 ---[ end trace 93d72a36b9146f22 ]--- Kdump: vmcore not initialized commit 020ec6537aa65c18e9084c568d7b94727f2026fd Author: Tejun Heo Date: Fri Apr 9 18:57:00 2010 +0900 percpu: factor out pcpu_addr_in_first/reserved_chunk() and update per_cpu_ptr_to_phys() Factor out pcpu_addr_in_first/reserved_chunk() from pcpu_chunk_addr_search() and use it to update per_cpu_ptr_to_phys() such that it handles first chunk differently from the rest. This patch doesn't cause any functional change and is to prepare for percpu nommu support. Signed-off-by: Tejun Heo Reviewed-by: David Howells Cc: Graff Yang Cc: Sonic Zhang diff --git a/mm/percpu.c b/mm/percpu.c index 6e09741..1aeb081 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -177,6 +177,21 @@ static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ static void pcpu_reclaim(struct work_struct *work); static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); +static bool pcpu_addr_in_first_chunk(void *addr) +{ + void *first_start = pcpu_first_chunk->base_addr; + + return addr >= first_start && addr < first_start + pcpu_unit_size; +} + +static bool pcpu_addr_in_reserved_chunk(void *addr) +{ + void *first_start = pcpu_first_chunk->base_addr; + + return addr >= first_start && + addr < first_start + pcpu_reserved_chunk_limit; +} + static int __pcpu_size_to_slot(int size) { int highbit = fls(size); /* size is in bytes */ @@ -334,12 +349,10 @@ static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) */ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) { - void *first_start = pcpu_first_chunk->base_addr; - /* is it in the first chunk? */ - if (addr >= first_start && addr < first_start + pcpu_unit_size) { + if (pcpu_addr_in_first_chunk(addr)) { /* is it in the reserved area? */ - if (addr < first_start + pcpu_reserved_chunk_limit) + if (pcpu_addr_in_reserved_chunk(addr)) return pcpu_reserved_chunk; return pcpu_first_chunk; } @@ -1343,10 +1356,13 @@ bool is_kernel_percpu_address(unsigned long addr) */ phys_addr_t per_cpu_ptr_to_phys(void *addr) { - if ((unsigned long)addr < VMALLOC_START || - (unsigned long)addr >= VMALLOC_END) - return __pa(addr); - else + if (pcpu_addr_in_first_chunk(addr)) { + if ((unsigned long)addr < VMALLOC_START || + (unsigned long)addr >= VMALLOC_END) + return __pa(addr); + else + return page_to_phys(vmalloc_to_page(addr)); + } else return page_to_phys(vmalloc_to_page(addr)); }