Hi, thanks for info. 30.03.2023 23:42, Lorenzo Stoakes пишет:
This seems to be a case of the documentation not quite being correct in the case of a MAP_PRIVATE file mapping, from the mremap man page discussing MREMAP_DONTUNMAP:-
Yes, it seems to be the case. However, current semantic of MREMAP_DONTUNMAP is unsatisfactory for many uses. Have you considered adding more flags to get things consistent? For my use-case, at the very least 1 more flag is needed to specify that in case of an anonymous mapping I need the source aliased not to zero-page but to destination mapping, so that the source and dest do match unless manually modified. Another similar flag may be needed to say that in case of a file-backed private mapping source needs to be converted to anonymous mapping, and if the first flag is also specified, then again source and dest would match. That can be used in case the private file-backed mapping was modified by hands. Overall I need a set of flags that can guarantee that MREMAP_DONTUNMAP doesn't change the source data. Can something like that be considered?
