If a given vmcore object has VMCORE_2ND_KERNEL type, target data is in
the buffer on 2nd kernel.

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

 fs/proc/vmcore.c |   64 ++++++++++++++++++++++++++----------------------------
 1 files changed, 31 insertions(+), 33 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 77e0a0e..4125a65 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -146,8 +146,7 @@ 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;
+       struct vmcore *m;
 
        if (buflen == 0 || *fpos >= vmcore_size)
                return 0;
@@ -173,39 +172,38 @@ 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;
-       if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
-               tsz = buflen;
-
-       /* Calculate left bytes in current memory segment. */
-       nr_bytes = (curr_m->size - (start - curr_m->paddr));
-       if (tsz > nr_bytes)
-               tsz = nr_bytes;
-
-       while (buflen) {
-               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;
+                       switch (m->type) {
+                       case VMCORE_OLD_MEMORY: {
+                               u64 paddr = m->paddr + *fpos - m->offset;
+
+                               tmp = read_from_oldmem(buffer, tsz, &paddr, 1);
+                               if (tmp < 0)
+                                       return tmp;
+                               break;
+                       }
+                       case VMCORE_2ND_KERNEL:
+                               if (copy_to_user(buffer,
+                                                m->buf + (*fpos - m->offset),
+                                                tsz))
+                                       return -EFAULT;
+                               break;
+                       }
+                       buflen -= tsz;
+                       *fpos += tsz;
+                       buffer += tsz;
+                       acc += tsz;
+
+                       /* leave now if filled buffer already */
+                       if (buflen == 0)
+                               return acc;
                }
-               if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
-                       tsz = buflen;
-               /* Calculate left bytes in current memory segment. */
-               nr_bytes = (curr_m->size - (start - curr_m->paddr));
-               if (tsz > nr_bytes)
-                       tsz = nr_bytes;
        }
+
        return acc;
 }
 

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