Re: [PATCH 09/20] signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON

[Linus Torvalds]

On Fri, Nov 12, 2021 at 11:57 AM Eric W. Biederman
<ebiederm@xxxxxxxxxxxx> wrote:
>
> Still user space would have had to have mapped address 0 to get that
> value set in do_sys_vm86.

You have to map address 0 anyway just to get vm86 mode to work.

vm86 mode fundamentally requires the low 1MB of virtual memory to be
mapped, since there is no virtual memory offset in the vm86 model.

             Linus