Re: [PATCH] prctl: Don't compile some of prctl functions when CRUI

[Michal Koutný]

Hi.

I see this discussion somewhat faded away since the previous year.

There was rework [1] that reduced (ab)use of mmap_sem in prctl
functions.

Actually, there still remains the down_write() in prctl_set_mm.
I considered at least replacing it with the mm_struct.arg_lock +
down_read() but then I learnt about this thread intending to remove that
part completely. I wouldn't oppose if CRIU is the sole (aware) user.

Ad the bot build issue, I could build the kernel both with
CONFIG_CHECKPOINT_RESTORE and without CONFIG_CHECKPOINT_RESTORE just
fine after applying the two proposed patches.

What is the current state? Perhaps, this change should be CCed to
linux-api@xxxxxxxxxxxxxxx(?).

Thanks,
Michal

[1] https://lore.kernel.org/lkml/1523730291-109696-1-git-send-email-yang.shi@xxxxxxxxxxxxxxxxx/T/