Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755352Ab3CEHGg (ORCPT ); Tue, 5 Mar 2013 02:06:36 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:44626 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755134Ab3CEHGe (ORCPT ); Tue, 5 Mar 2013 02:06:34 -0500 From: HATAYAMA Daisuke Subject: [PATCH v2 17/20] vmcore: check if vmcore objects satify mmap()'s page-size boundary requirement To: vgoyal@redhat.com, ebiederm@xmission.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, heiko.carstens@de.ibm.com, akpm@linux-foundation.org Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org Date: Sat, 02 Mar 2013 17:37:25 +0900 Message-ID: <20130302083725.31252.54610.stgit@localhost6.localdomain6> In-Reply-To: <20130302083447.31252.93914.stgit@localhost6.localdomain6> References: <20130302083447.31252.93914.stgit@localhost6.localdomain6> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2127 Lines: 67 If there's some vmcore object that doesn't satisfy page-size boundary requirement, remap_pfn_range() fails to remap it to user-space. Objects that posisbly don't satisfy the requirement are ELF note segments only. The memory chunks corresponding to PT_LOAD entries are guaranteed to satisfy page-size boundary requirement by the copy from old memory to buffer in 2nd kernel done in later patch. Signed-off-by: HATAYAMA Daisuke --- fs/proc/vmcore.c | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index e432946..5582aaa 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -38,6 +38,8 @@ static u64 vmcore_size; static struct proc_dir_entry *proc_vmcore = NULL; +static bool support_mmap_vmcore; + /* * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error * The called function has to take care of module refcounting. @@ -897,6 +899,7 @@ static int __init parse_crash_elf_headers(void) static int __init vmcore_init(void) { int rc = 0; + struct vmcore *m; /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/ if (!(is_vmcore_usable())) @@ -907,6 +910,25 @@ static int __init vmcore_init(void) return rc; } + /* If some object doesn't satisfy PAGE_SIZE boundary + * requirement, mmap_vmcore() is not exported to + * user-space. */ + support_mmap_vmcore = true; + list_for_each_entry(m, &vmcore_list, list) { + u64 paddr; + + if (m->flag & MEM_TYPE_CURRENT_KERNEL) + paddr = (u64)__pa(m->buf); + else + paddr = m->paddr; + + if ((m->offset & ~PAGE_MASK) || (paddr & ~PAGE_MASK) + || (m->size & ~PAGE_MASK)) { + support_mmap_vmcore = false; + break; + } + } + proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations); if (proc_vmcore) proc_vmcore->size = vmcore_size; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/