Messages in this thread |  | | From | Pedro Falcato <> | | Date | Wed, 7 Aug 2024 22:20:44 +0100 | | Subject | Re: [PATCH v1] selftest mm/mseal: fix test_seal_mremap_move_dontunmap_anyaddr |
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On Wed, Aug 7, 2024 at 7:03 PM Jeff Xu <jeffxu@google.com> wrote: <snip> > > test_seal_mremap_move_dontunmap use 0 as new_addr, 0 indicates > allocating a new memory. > test_seal_mremap_move_dontunmap_anyaddr uses any arbitrary address as > a new address.
No, MREMAP_DONTUNMAP uses the address you pass as a hint, aka you're just testing get_unmapped_area, not any mseal capability. There's no forced moving here.
> > > You also don't know if 0xdead0000 is a valid page (hexagon for > > instance seems to support 256KiB and 1MiB pages, so does ppc32, and > > this is not something that should be hardcoded). > > > usually hardcode value is not good practice, but the point of this > test is to show > mremap can really relocate the mapping to an arbitrary address.
That's what test_seal_mremap_move_dontunmap does, no?
> > Do you have any suggestions here ? I can think of two options to choose from: > > 1> use 0xd0000000 > 2> allocate a memory then free it, reuse the ptr.
Personally I'd prefer 2, if you really want to keep the test. It's also a strategy used elsewhere (e.g mremap_dontunmap.c).
FWIW I don't have the mental strength to bikeshed over this any more, so please do what you think is best!
-- Pedro
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