From: Khalid Aziz <khalid.a...@oracle.com>
Date: Wed, 30 Aug 2017 16:27:54 -0600
>>> +#define arch_calc_vm_prot_bits(prot, pkey)
>>> sparc_calc_vm_prot_bits(prot)
>>> +static inline unsigned long sparc_calc_vm_prot_bits(unsigned long
>>> prot)
>>> +{
>>> + if (prot & PROT_ADI) {
>>> + struct pt_regs *regs;
>>> +
>>> + if (!current->mm->context.adi) {
>>> + regs = task_pt_regs(current);
>>> + regs->tstate |= TSTATE_MCDE;
>>> + current->mm->context.adi = true;
>> If a process is multi-threaded when it enables ADI on some memory for
>> the first time, TSTATE_MCDE will only be set for the calling thread
>> and it will not be possible to enable it for the other threads.
>> One possible way to handle this is to enable TSTATE_MCDE for all user
>> threads when they are initialized if adi_capable() returns true.
>>
>
> Or set TSTATE_MCDE unconditionally here by removing "if
> (!current->mm->context.adi)"?
I think you have to make "ADI enabled" a property of the mm_struct.
Then you can broadcast to mm->cpu_vm_mask a per-cpu interrupt that
updates regs->tstate of a thread using 'mm' is currently executing.
And in the context switch code you set TSTATE_MCDE if it's not set
already.
That should cover all threaded case.
