* Xiao Guangrong (guangrong.xiao@xxxxxxxxx) wrote: > > > On 08/08/2018 01:08 PM, Peter Xu wrote: > > On Tue, Aug 07, 2018 at 05:12:07PM +0800, guangrong.xiao@xxxxxxxxx wrote: > > > From: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxx> > > > > > > ram_find_and_save_block() can return negative if any error hanppens, > > > however, it is completely ignored in current code > > > > Could you hint me where we'll return an error? > > > > I think control_save_page() may return a error condition but i am not > good at it ... Other places look safe _currently_. These functions were > designed to have error returned anyway. ram_control_save_page's return is checked by control_save_page which returns true/false but sets *pages to a return value. What I'd need to follow closely is the case where ram_control_save_page returns RAM_SAVE_CONTROL_DELAYED, in that case control_save_page I think returns with *pages=-1 and returns true. And I think in that case ram_save_target_page can leak that -1 - hmm. Now, ram_save_host_page already checks for <0 and will return that, but I think that would potentially loop in ram_find_and_save_block; I'm not sure we want to change that or not! Dave > > > (Anyway I agree that the error handling is not that good, mostly > > because the QEMUFile APIs does not provide proper return code, e.g., > > qemu_put_be64 returns void) > > > > Yes, it is, the returned error condition is mixed in file's API and > function's return value... :( > -- Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK
