On Thu, Aug 27, 2020 at 11:15:12AM -0700, Linus Torvalds wrote:
> > SYM_FUNC_START(__put_user_2)
> > - ENTER
> > - mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
> > + LOAD_TASK_SIZE_MAX
> > sub $1,%_ASM_BX
>
> It's even more obvious here. We load a constant and then immediately
On Thu, Aug 27, 2020 at 8:00 AM Christoph Hellwig wrote:
>
> SYM_FUNC_START(__get_user_2)
> add $1,%_ASM_AX
> jc bad_get_user
This no longer makes sense, and
> - mov PER_CPU_VAR(current_task), %_ASM_DX
> - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
> + LOAD_TASK_SI
Stop providing the possibility to override the address space using
set_fs() now that there is no need for that any more. To properly
handle the TASK_SIZE_MAX checking for 4 vs 5-level page tables on
x86 a new alternative is introduced, which just like the one in
entry_64.S has to use the hardcoded
