Re: general protection fault vs Oops

From: Cong Wang
Date: Sun May 17 2020 - 16:47:16 EST


On Sat, May 16, 2020 at 9:16 AM Subhashini Rao Beerisetty
<subhashbeerisetty@xxxxxxxxx> wrote:
> Yes, those are out-of-tree modules. Basically, my question is, in
> general what is the difference between 'general protection fault' and
> 'Oops' failure in kernel mode.

For your case, they are likely just different consequences of a same
memory error. Let's assume it is a use-after-free, the behavior is UAF
is undefined: If that memory freed by kernel is also unmapped from
kernel address space, you would get a page fault when using it
afterward, that is an Oops. Or if that memory freed by kernel gets
reallocated and remapped as read-only, you would get a general
protection error when you writing to it afterward.