Re: [RFC PATCH] x86/mm/fault: Allow stack access below %rsp

From: Waiman Long
Date: Fri Nov 02 2018 - 15:50:22 EST


On 11/02/2018 03:44 PM, Dave Hansen wrote:
> On 11/2/18 12:40 PM, Waiman Long wrote:
>> The 64k+ limit check is kind of arbitrary. So the check is now removed
>> to just let expand_stack() decide if a segmentation fault should happen.
> With the 64k check removed, what's the next limit that we bump into? Is
> it just the stack_guard_gap space above the next-lowest VMA?

I think it is both the stack_guard_gap space above the next lowest VMA
and the rlimit(RLIMIT_STACK).

Cheers,
Longman