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Subject[PATCH 07/13] vmcore: modify read_vmcore() to read buffer on 2nd kernel
Date
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.hatayama@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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