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From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
To: vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org
Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	lisa.mitchell@hp.com, zhangyanfei@cn.fujitsu.com,
	kumagai-atsushi@mxc.nes.nec.co.jp, cpw@sgi.com,
	jingbai.ma@hp.com
Subject: [PATCH v4 7/8] vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list
Date: Sat, 13 Apr 2013 09:21:46 +0900	[thread overview]
Message-ID: <20130413002145.18245.73180.stgit@localhost6.localdomain6> (raw)
In-Reply-To: <20130413002000.18245.21513.stgit@localhost6.localdomain6>

Treat memory chunks referenced by PT_LOAD program header entries in
page-size boundary in vmcore_list. Formally, for each range [start,
end], we set up the corresponding vmcore object in vmcore_list to
[rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)].

This change affects layout of /proc/vmcore. The gaps generated by the
rearrangement are newly made visible to applications as
holes. Concretely, they are two ranges [rounddown(start, PAGE_SIZE),
start] and [end, roundup(end, PAGE_SIZE)].

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
---

 fs/proc/vmcore.c |   26 ++++++++++++++++++++------
 1 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 029bdc0..cd0f9d9 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -477,16 +477,23 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
 	vmcore_off = elfsz + roundup(phdr_ptr->p_memsz, PAGE_SIZE);
 
 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		u64 paddr, start, end, size;
+
 		if (phdr_ptr->p_type != PT_LOAD)
 			continue;
 
+		paddr = phdr_ptr->p_offset;
+		start = rounddown(paddr, PAGE_SIZE);
+		end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
+		size = end - start;
+
 		/* Add this contiguous chunk of memory to vmcore list.*/
-		if (vmcore_add(vc_list, phdr_ptr->p_offset, phdr_ptr->p_memsz))
+		if (vmcore_add(vc_list, start, size))
 			return -ENOMEM;
 
 		/* Update the program header offset. */
-		phdr_ptr->p_offset = vmcore_off;
-		vmcore_off = vmcore_off + phdr_ptr->p_memsz;
+		phdr_ptr->p_offset = vmcore_off + (paddr - start);
+		vmcore_off = vmcore_off + size;
 	}
 	return 0;
 }
@@ -507,16 +514,23 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
 	vmcore_off = elfsz + roundup(phdr_ptr->p_memsz, PAGE_SIZE);
 
 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+		u64 paddr, start, end, size;
+
 		if (phdr_ptr->p_type != PT_LOAD)
 			continue;
 
+		paddr = phdr_ptr->p_offset;
+		start = rounddown(paddr, PAGE_SIZE);
+		end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
+		size = end - start;
+
 		/* Add this contiguous chunk of memory to vmcore list.*/
-		if (vmcore_add(vc_list, phdr_ptr->p_offset, phdr_ptr->p_memsz))
+		if (vmcore_add(vc_list, start, size))
 			return -ENOMEM;
 
 		/* Update the program header offset */
-		phdr_ptr->p_offset = vmcore_off;
-		vmcore_off = vmcore_off + phdr_ptr->p_memsz;
+		phdr_ptr->p_offset = vmcore_off + (paddr - start);
+		vmcore_off = vmcore_off + size;
 	}
 	return 0;
 }


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  parent reply	other threads:[~2013-04-18  9:35 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-13  0:21 [PATCH v4 0/8] kdump, vmcore: support mmap() on /proc/vmcore HATAYAMA Daisuke
2013-04-13  0:21 ` [PATCH v4 1/8] vmcore: allocate buffer for ELF headers on page-size alignment HATAYAMA Daisuke
2013-04-13  0:21 ` [PATCH v4 2/8] vmcore: clean up read_vmcore() HATAYAMA Daisuke
2013-04-13  0:21 ` [PATCH v4 3/8] vmcore, procfs: introduce MEM_TYPE_CURRENT_KERNEL flag to distinguish objects copied in 2nd kernel HATAYAMA Daisuke
2013-04-13  0:21 ` [PATCH v4 4/8] vmcore: Add helper function vmcore_add() HATAYAMA Daisuke
2013-04-13  0:21 ` [PATCH v4 5/8] vmcore: copy ELF note segments in the 2nd kernel per page vmcore objects HATAYAMA Daisuke
2013-04-29 19:36   ` Vivek Goyal
2013-05-07  7:56     ` HATAYAMA Daisuke
2013-05-07 15:08       ` Vivek Goyal
2013-05-08  4:57         ` HATAYAMA Daisuke
2013-04-13  0:21 ` [PATCH v4 6/8] vmcore: count holes generated by round-up operation for page boudary for size of /proc/vmcore HATAYAMA Daisuke
2013-04-13  0:21 ` HATAYAMA Daisuke [this message]
2013-04-29 19:51   ` [PATCH v4 7/8] vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list Vivek Goyal
2013-05-07  7:38     ` HATAYAMA Daisuke
2013-05-07 15:24       ` Vivek Goyal
2013-04-13  0:21 ` [PATCH v4 8/8] vmcore: support mmap() on /proc/vmcore HATAYAMA Daisuke
2013-04-25 13:38 ` [PATCH v4 0/8] kdump, " Cliff Wickman

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