On Thu, Feb 14, 2013 at 07:12:21PM +0900, HATAYAMA Daisuke wrote: > If a given vmcore object has VMCORE_2ND_KERNEL type, target data is in > the buffer on 2nd kernel. > Looks like this patch is doing two things. - Cleanup how read is performed. Get rid of map_offset_to_paddr() and open code it and use list_for_each_entry(). - Read some memory from current kernel if VMCORE_2ND_KERNEL is set. Can you break it down in two patches. Thanks Vivek > Signed-off-by: HATAYAMA Daisuke <d.hatayama at 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; > } >