Re: [GIT PULL] Please pull proc and exec work for 5.7-rc1

[Linus Torvalds]

On Fri, Apr 3, 2020 at 1:41 PM Waiman Long <longman@xxxxxxxxxx> wrote:
>
> Another alternative is to add new functions like down_read_unfair() that
> perform unfair read locking for its callers. That will require less code
> change, but the calling functions have to make the right choice.

I'd prefer the static choice model - and I'd hide this in some
"task_cred_read_lock()" function anyway rather than have the users do
"mutex_lock_killable(&task->signal->cred_guard_mutex)" like they do
now.

How nasty would it be to add the "upgrade" op? I took a quick look,
but that just made me go "Waiman would know" ;)

             Linus