+ vmcore-clean-up-read_vmcore.patch added to -mm tree

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Subject: + vmcore-clean-up-read_vmcore.patch added to -mm tree
To: d.hatayama@xxxxxxxxxxxxxx,kosaki.motohiro@xxxxxxxxxxxxxx,kumagai-atsushi@xxxxxxxxxxxxxxxxx,lisa.mitchell@xxxxxx,vgoyal@xxxxxxxxxx,zhangyanfei@xxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Thu, 23 May 2013 15:25:00 -0700


The patch titled
     Subject: vmcore: clean up read_vmcore()
has been added to the -mm tree.  Its filename is
     vmcore-clean-up-read_vmcore.patch

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------------------------------------------------------
From: HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx>
Subject: vmcore: clean up read_vmcore()

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 <d.hatayama@xxxxxxxxxxxxxx>
Acked-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Atsushi Kumagai <kumagai-atsushi@xxxxxxxxxxxxxxxxx>
Cc: Lisa Mitchell <lisa.mitchell@xxxxxx>
Cc: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 fs/proc/vmcore.c |   68 +++++++++++++--------------------------------
 1 file changed, 20 insertions(+), 48 deletions(-)

diff -puN fs/proc/vmcore.c~vmcore-clean-up-read_vmcore fs/proc/vmcore.c
--- a/fs/proc/vmcore.c~vmcore-clean-up-read_vmcore
+++ a/fs/proc/vmcore.c
@@ -118,27 +118,6 @@ static ssize_t read_from_oldmem(char *bu
 	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 *
 {
 	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 *
 			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;
 }
 
_

Patches currently in -mm which might be from d.hatayama@xxxxxxxxxxxxxx are

include-linux-mmh-add-page_aligned-helper.patch
vmcore-clean-up-read_vmcore.patch
vmcore-allocate-buffer-for-elf-headers-on-page-size-alignment.patch
vmcore-allocate-buffer-for-elf-headers-on-page-size-alignment-fix.patch
vmcore-treat-memory-chunks-referenced-by-pt_load-program-header-entries-in-page-size-boundary-in-vmcore_list.patch
vmalloc-make-find_vm_area-check-in-range.patch
vmalloc-introduce-remap_vmalloc_range_partial.patch
vmalloc-introduce-remap_vmalloc_range_partial-fix.patch
vmcore-allocate-elf-note-segment-in-the-2nd-kernel-vmalloc-memory.patch
vmcore-allocate-elf-note-segment-in-the-2nd-kernel-vmalloc-memory-fix.patch
vmcore-allow-user-process-to-remap-elf-note-segment-buffer.patch
vmcore-allow-user-process-to-remap-elf-note-segment-buffer-fix.patch
vmcore-calculate-vmcore-file-size-from-buffer-size-and-total-size-of-vmcore-objects.patch
vmcore-support-mmap-on-proc-vmcore.patch
vmcore-support-mmap-on-proc-vmcore-fix.patch

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