On Sun, 2010-10-17 at 20:43 +0200, Michael S. Tsirkin wrote:
> host_from_stream_offset returns NULL on error,
> return error instead of trying to use that address,
> to avoid segfault on invalid stream.
>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
> ---
> arch_init.c | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index e468c0c..bc7528d 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -116,6 +116,8 @@ static int ram_save_block(QEMUFile *f)
>
> if (!block)
> block = QLIST_FIRST(&ram_list.blocks);
> + if (!last_block)
> + last_block = block;
>
> current_addr = block->offset + offset;
NAK, last_block == block will cause us to set the continue flag on the
first block. I assume you're trying to prevent the last_block->offset
segv in the while test, but that should never happen. The only time
last_block is NULL is at the beginning of stage 1, where all pages are
dirty. At that point we should always enter the if {} block at the
beginning of the do {} while, which breaks out rather than hitting the
segv. We'll then set last_block for the next pass.
> @@ -390,6 +392,9 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
> host = qemu_get_ram_ptr(addr);
> else
> host = host_from_stream_offset(f, addr, flags);
> + if (!host) {
> + return -EINVAL;
> + }
>
This should also never happen since we've synchronized ramblocks at the
beginning of migration, but probably a good idea to return an error.
Thanks,
Alex
