Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754589Ab3CEHFj (ORCPT ); Tue, 5 Mar 2013 02:05:39 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:44533 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753805Ab3CEHFf (ORCPT ); Tue, 5 Mar 2013 02:05:35 -0500 From: HATAYAMA Daisuke Subject: [PATCH v2 07/20] vmcore: copy non page-size aligned head and tail pages in 2nd kernel 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 17:36:27 +0900 Message-ID: <20130302083627.31252.41277.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: 7263 Lines: 281 Due to mmap() requirement, we need to copy pages not starting or ending with page-size aligned address in 2nd kernel and to map them to user-space. For example, see the map below: 00000000-0001ffff : reserved 00010000-0009f7ff : System RAM 0009f800-0009ffff : reserved where the System RAM ends with 0x9f800 that is not page-size aligned. This map is divided into two parts: 00010000-0009dfff 0009f000-0009f7ff and the first one is kept in old memory and the 2nd one is copied into buffer on 2nd kernel. This kind of non-page-size-aligned area can always occur since any part of System RAM can be converted into reserved area at runtime. If not doing copying like this and if remapping non page-size aligned pages on old memory directly, mmap() had to export memory which is not dump target to user-space. In the above example this is reserved 0x9f800-0xa0000. Signed-off-by: HATAYAMA Daisuke --- fs/proc/vmcore.c | 192 ++++++++++++++++++++++++++++++++++++++++++++++++------ 1 files changed, 172 insertions(+), 20 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index c511cf4..6b071b4 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -474,11 +474,10 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, size_t elfsz, struct list_head *vc_list) { - int i; + int i, rc; Elf64_Ehdr *ehdr_ptr; Elf64_Phdr *phdr_ptr; loff_t vmcore_off; - struct vmcore *new; ehdr_ptr = (Elf64_Ehdr *)elfptr; phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */ @@ -488,20 +487,97 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, PAGE_SIZE); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 start, end, rest; + if (phdr_ptr->p_type != PT_LOAD) continue; - /* Add this contiguous chunk of memory to vmcore list.*/ - new = get_new_element(); - if (!new) - return -ENOMEM; - new->paddr = phdr_ptr->p_offset; - new->size = phdr_ptr->p_memsz; - list_add_tail(&new->list, vc_list); + start = phdr_ptr->p_offset; + end = phdr_ptr->p_offset + phdr_ptr->p_memsz; + rest = phdr_ptr->p_memsz; + + if (start & ~PAGE_MASK) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = start; + len = min(roundup(start,PAGE_SIZE), end) - start; + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf + (start & ~PAGE_MASK), len, + &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->flag |= MEM_TYPE_CURRENT_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } + + if (rest > 0 && + roundup(start, PAGE_SIZE) < rounddown(end, PAGE_SIZE)) { + u64 paddr, len; + struct vmcore *new; + + paddr = roundup(start, PAGE_SIZE); + len =rounddown(end,PAGE_SIZE)-roundup(start,PAGE_SIZE); + + new = get_new_element(); + if (!new) + return -ENOMEM; + new->paddr = paddr; + new->size = len; + list_add_tail(&new->list, vc_list); + + rest -= len; + } + + if (rest > 0) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = rounddown(end, PAGE_SIZE); + len = end - rounddown(end, PAGE_SIZE); + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf, len, &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->flag |= MEM_TYPE_CURRENT_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } /* Update the program header offset. */ phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + vmcore_off +=roundup(end,PAGE_SIZE)-rounddown(start,PAGE_SIZE); } return 0; } @@ -510,11 +586,10 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, size_t elfsz, struct list_head *vc_list) { - int i; + int i, rc; Elf32_Ehdr *ehdr_ptr; Elf32_Phdr *phdr_ptr; loff_t vmcore_off; - struct vmcore *new; ehdr_ptr = (Elf32_Ehdr *)elfptr; phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */ @@ -524,20 +599,97 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, PAGE_SIZE); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 start, end, rest; + if (phdr_ptr->p_type != PT_LOAD) continue; - /* Add this contiguous chunk of memory to vmcore list.*/ - new = get_new_element(); - if (!new) - return -ENOMEM; - new->paddr = phdr_ptr->p_offset; - new->size = phdr_ptr->p_memsz; - list_add_tail(&new->list, vc_list); + start = phdr_ptr->p_offset; + end = phdr_ptr->p_offset + phdr_ptr->p_memsz; + rest = phdr_ptr->p_memsz; + + if (start & ~PAGE_MASK) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = start; + len = min(roundup(start,PAGE_SIZE), end) - start; + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf + (start & ~PAGE_MASK), len, + &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->flag |= MEM_TYPE_CURRENT_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } + + if (rest > 0 && + roundup(start, PAGE_SIZE) < rounddown(end, PAGE_SIZE)) { + u64 paddr, len; + struct vmcore *new; + + paddr = roundup(start, PAGE_SIZE); + len =rounddown(end,PAGE_SIZE)-roundup(start,PAGE_SIZE); + + new = get_new_element(); + if (!new) + return -ENOMEM; + new->paddr = paddr; + new->size = len; + list_add_tail(&new->list, vc_list); + + rest -= len; + } + + if (rest > 0) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = rounddown(end, PAGE_SIZE); + len = end - rounddown(end, PAGE_SIZE); + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf, len, &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->flag |= MEM_TYPE_CURRENT_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } /* Update the program header offset */ phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + vmcore_off +=roundup(end,PAGE_SIZE)-rounddown(start,PAGE_SIZE); } return 0; } -- 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/