From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx105.postini.com [74.125.245.105]) by kanga.kvack.org (Postfix) with SMTP id 0D4D06B0032 for ; Tue, 21 May 2013 22:55:40 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 88A5A3EE0C1 for ; Wed, 22 May 2013 11:55:39 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 6DAA745DE4E for ; Wed, 22 May 2013 11:55:39 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1F11A45DE53 for ; Wed, 22 May 2013 11:55:39 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 0B2D7E08001 for ; Wed, 22 May 2013 11:55:39 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 8A3111DB8037 for ; Wed, 22 May 2013 11:55:38 +0900 (JST) From: HATAYAMA Daisuke Subject: [PATCH v7 1/8] vmcore: clean up read_vmcore() Date: Wed, 22 May 2013 11:55:37 +0900 Message-ID: <20130522025537.12215.30169.stgit@localhost6.localdomain6> In-Reply-To: <20130522025410.12215.16793.stgit@localhost6.localdomain6> References: <20130522025410.12215.16793.stgit@localhost6.localdomain6> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org Cc: cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com, jingbai.ma@hp.com, linux-mm@kvack.org, riel@redhat.com, walken@google.com, hughd@google.com, kosaki.motohiro@jp.fujitsu.com Rewrite part of read_vmcore() that reads objects in vmcore_list in the same way as part reading ELF headers, by which some duplicated and redundant codes are removed. Signed-off-by: HATAYAMA Daisuke Acked-by: Vivek Goyal --- fs/proc/vmcore.c | 68 ++++++++++++++++-------------------------------------- 1 files changed, 20 insertions(+), 48 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 17f7e08..ab0c92e 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -118,27 +118,6 @@ static ssize_t read_from_oldmem(char *buf, size_t count, return read; } -/* Maps vmcore file offset to respective physical address in memroy. */ -static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list, - struct vmcore **m_ptr) -{ - struct vmcore *m; - u64 paddr; - - list_for_each_entry(m, vc_list, list) { - u64 start, end; - start = m->offset; - end = m->offset + m->size - 1; - if (offset >= start && offset <= end) { - paddr = m->paddr + offset - start; - *m_ptr = m; - return paddr; - } - } - *m_ptr = NULL; - return 0; -} - /* Read from the ELF header and then the crash dump. On error, negative value is * returned otherwise number of bytes read are returned. */ @@ -147,8 +126,8 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer, { ssize_t acc = 0, tmp; size_t tsz; - u64 start, nr_bytes; - struct vmcore *curr_m = NULL; + u64 start; + struct vmcore *m = NULL; if (buflen == 0 || *fpos >= vmcore_size) return 0; @@ -174,33 +153,26 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer, return acc; } - start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m); - if (!curr_m) - return -EINVAL; - - while (buflen) { - tsz = min_t(size_t, buflen, PAGE_SIZE - (start & ~PAGE_MASK)); - - /* Calculate left bytes in current memory segment. */ - nr_bytes = (curr_m->size - (start - curr_m->paddr)); - if (tsz > nr_bytes) - tsz = nr_bytes; - - tmp = read_from_oldmem(buffer, tsz, &start, 1); - if (tmp < 0) - return tmp; - buflen -= tsz; - *fpos += tsz; - buffer += tsz; - acc += tsz; - if (start >= (curr_m->paddr + curr_m->size)) { - if (curr_m->list.next == &vmcore_list) - return acc; /*EOF*/ - curr_m = list_entry(curr_m->list.next, - struct vmcore, list); - start = curr_m->paddr; + list_for_each_entry(m, &vmcore_list, list) { + if (*fpos < m->offset + m->size) { + tsz = m->offset + m->size - *fpos; + if (buflen < tsz) + tsz = buflen; + start = m->paddr + *fpos - m->offset; + tmp = read_from_oldmem(buffer, tsz, &start, 1); + if (tmp < 0) + return tmp; + buflen -= tsz; + *fpos += tsz; + buffer += tsz; + acc += tsz; + + /* leave now if filled buffer already */ + if (buflen == 0) + return acc; } } + return acc; } -- 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