[PATCH v2 10/20] vmcore: read buffers for vmcore objects copied from old memory

HATAYAMA Daisuke
2013-03-05T07:05:56Z

If flag MEM_TYPE_CURRENT_KERNEL is set, the object is copied in the
buffer on the 2nd kernel, then read_vmcore() reads the buffer. If the
flag is not set, read_vmcore() reads old memory as usual.

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

fs/proc/vmcore.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 09b7f34..c8899dc 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -158,10 +158,17 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer,
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;
+ if (m->flag & MEM_TYPE_CURRENT_KERNEL) {
+ if (copy_to_user(buffer,
+ m->buf + *fpos - m->offset,
+ tsz))
+ return -EFAULT;
+ } else {
+ 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;