Re: [PATCH v3] x86/mce: Avoid infinite loop for copy from user recovery

On Fri, Jan 15, 2021 at 11:34:35AM -0800, Luck, Tony wrote: > In the user mode case we should only bump mce_count to "1" and > before task_work() gets called. Ok, right, it should not be possible to trigger a second MCE while queue_task_work() runs when it is a user MCE. The handler itself won't

Re: [PATCH v3] x86/mce: Avoid infinite loop for copy from user recovery

On Fri, Jan 15, 2021 at 04:27:54PM +0100, Borislav Petkov wrote: > On Thu, Jan 14, 2021 at 04:38:17PM -0800, Tony Luck wrote: > > Add a "mce_busy" counter so that task_work_add() is only called once > > per faulty page in this task. > > Yeah, that sentence can be removed now too. I will update

Re: [PATCH v3] x86/mce: Avoid infinite loop for copy from user recovery

On Thu, Jan 14, 2021 at 04:38:17PM -0800, Tony Luck wrote: > Recovery action when get_user() triggers a machine check uses the fixup > path to make get_user() return -EFAULT. Also queue_task_work() sets up > so that kill_me_maybe() will be called on return to user mode to send a > SIGBUS to the