RE: [PATCH v2] mm: hwpoison: coredump: support recovery from dump_user_range()

[Luck, Tony]

> > But in the core dump case there is no return to user. The process is being
> > terminated by the signal that leads to this core dump. So even though you
> > may consider the page being accessed to be a "user" page, you can't fix
> > it by queueing work to run on return to user.
> 
> For coredump，the task work will be called too, see following code,
> 
> get_signal
> 	sig_kernel_coredump
> 		elf_core_dump
> 			dump_user_range
> 				_copy_from_iter // with MC-safe copy, return without panic
> 	do_group_exit(ksig->info.si_signo);
> 		do_exit
> 			exit_task_work
> 				task_work_run
> 					kill_me_never
> 						memory_failure
> 

Nice. I didn't realize that the exit code path would clear any pending task_work() requests.
But it makes sense that this happens. Thanks for filling a gap in my knowledge.

-Tony