On Mon, 2019-06-10 at 15:59 -0700, Dave Hansen wrote: > On 6/10/19 3:40 PM, Yu-cheng Yu wrote: > > Ok, we will go back to do_mmap() with MAP_PRIVATE, MAP_NORESERVE and > > VM_DONTDUMP. The bitmap will cover only 48-bit address space. > > Could you make sure to discuss the downsides of only doing a 48-bit > address space? The downside is that we cannot load legacy lib's above 48-bit address space, but currently ld-linux does not do that. Should ld-linux do that in the future, dlopen() fails. Considering CRIU migration, we probably need to do this anyway? > What are the reasons behind and implications of VM_DONTDUMP? The bitmap is very big. In GDB, it should be easy to tell why a control-protection fault occurred without the bitmap. Yu-cheng
