On Wed, 31 Mar 2021 at 16:51, Peter Zijlstra peterz@infradead.org wrote:
On Wed, Mar 31, 2021 at 02:32:58PM +0200, Marco Elver wrote:
On Mon, 29 Mar 2021 at 14:07, Peter Zijlstra peterz@infradead.org wrote:
(and we might already have a problem on some architectures where there can be significant time between these due to not having arch_irq_work_raise(), so ideally we ought to double check current in your case)
I missed this bit -- just to verify: here we want to check that event->ctx->task == current, in case the the irq_work runs when the current task has already been replaced. Correct?
Yeah, just not sure what a decent failure would be, silent ignore seems undesired, maybe WARN and archs that can trigger it get to fix it ?
I'll go with a WARN and add a comment.
This also revealed there should be a requirement that sigtrap events must be associated with a task (syzkaller managed to trigger the warning for cpu events).
Thanks, -- Marco