Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 13 May 2020 19:43:24 -0700 | Subject | Re: [PATCH 11/18] maccess: remove strncpy_from_unsafe |
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On Wed, May 13, 2020 at 6:00 PM Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > But we should likely at least disallow it entirely on platforms where > > we really can't - or pick one hardcoded choice. On sparc, you really > > _have_ to specify one or the other. > > OK. BTW, is there any way to detect the kernel/user space overlap on > memory layout statically? If there, I can do it. (I don't like > "if (CONFIG_X86)" thing....) > Or, maybe we need CONFIG_ARCH_OVERLAP_ADDRESS_SPACE?
I think it would be better to have a CONFIG variable that architectures can just 'select' to show that they are ok with separate kernel and user addresses.
Because I don't think we have any way to say that right now as-is. You can probably come up with hacky ways to approximate it, ie something like
if (TASK_SIZE_MAX > PAGE_OFFSET) .... they overlap ..
which would almost work, but..
Linus
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