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vmcore: clean up read_vmcore()

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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>
This commit is contained in:
HATAYAMA Daisuke 2013-07-03 15:02:13 -07:00 committed by Linus Torvalds
parent 0fa73b86ef
commit b27eb18660
1 changed files with 19 additions and 47 deletions
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66
fs/proc/vmcore.c
View file

@ -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;
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;
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;
/* leave now if filled buffer already */
if (buflen == 0)
return acc;
}
}
return acc;
}