Re: [PATCH] mm: hwpoison: use do_send_sig_info() instead of force_sig() (Re: PMEM error-handling forces SIGKILL causes kernel panic)

From: Naoya Horiguchi
Date: Wed Jan 16 2019 - 18:40:04 EST


Hi Jane,

On Wed, Jan 16, 2019 at 09:56:02AM -0800, Jane Chu wrote:
> Hi, Naoya,
>
> On 1/16/2019 1:30 AM, Naoya Horiguchi wrote:
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 7c72f2a95785..831be5ff5f4d 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -372,7 +372,8 @@ static void kill_procs(struct list_head *to_kill, int forcekill, bool fail,
> if (fail || tk->addr_valid == 0) {
> pr_err("Memory failure: %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
> pfn, tk->tsk->comm, tk->tsk->pid);
> - force_sig(SIGKILL, tk->tsk);
> + do_send_sig_info(SIGKILL, SEND_SIG_PRIV,
> + tk->tsk, PIDTYPE_PID);
> }
>
>
> Since we don't care the return from do_send_sig_info(), would you mind to
> prefix it with (void) ?

Sorry, I'm not sure about the benefit to do casting the return value
just being ignored, so personally I'd like keeping the code simple.
Do you have some in mind?

- Naoya