Am 05.06.25 um 11:04 schrieb Alexander Gordeev:
On Wed, Jun 04, 2025 at 07:40:43PM +0200, Claudio Imbrenda wrote:
This could trigger WARN_ON_ONCE() in handle_fault_error_nolock():
if (WARN_ON_ONCE(!si_code))
si_code = SEGV_MAPERR;
Would this warning be justified in this case (aka user_mode(regs) ==
true)?
I think so, because if we are in usermode, we should never trigger
faulthandler_disabled()
I think I do not get you. We are in a system call and also in_atomic(),
so faulthandler_disabled() is true and handle_fault_error_nolock(regs, 0)
is called (above).
what is the psw in regs?
is it not the one that was being used when the exception was triggered?
Hmm, right. I assume is_kernel_fault() returns false not because
user_mode(regs) is true, but because we access the secondary AS.
Still, to me it feels wrong to trigger that warning due to a user
process activity. But anyway:
Acked-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Can we trigger a WARN from userspace?
