On 10/03/2017 14:44, Yang Zhong wrote:
> Since cpu-memory and memory have same address space,one malloced
> memory is enough. This patch will skip memory malloc for memory
> address space,which will reduce around 3M physical memory in heap.
>
> Signed-off-by: Yang Zhong <yang.zh...@intel.com>
> ---
> memory.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/memory.c b/memory.c
> index 284894b..6af80e7 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -2422,7 +2422,7 @@ AddressSpace *address_space_init_shareable(MemoryRegion
> *root, const char *name)
> AddressSpace *as;
>
> QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
> - if (root == as->root && as->malloced) {
> + if (root == as->root) {
> as->ref_count++;
> return as;
> }
>
This has the same problem as v1.
If as->malloced is false, the AddressSpace might be embedded in another
struct. This other struct could be freed when as->ref_count is still
greater than 0, causing a use-after-free bug.
Paolo
