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authorHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>2013-07-03 15:02:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 16:07:30 -0700
commitb27eb186608c89ef0979ae47c649859ceaa1b2e7 (patch)
tree02bf3f94555e4c42773af8f544871ef9785a2c15 /fs/proc/vmcore.c
parent0fa73b86ef0797ca4fde5334117ca0b330f08030 (diff)
downloadop-kernel-dev-b27eb186608c89ef0979ae47c649859ceaa1b2e7.zip
op-kernel-dev-b27eb186608c89ef0979ae47c649859ceaa1b2e7.tar.gz
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@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/vmcore.c')
-rw-r--r--fs/proc/vmcore.c68
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;
}
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