Linux IA64 platform development
 help / color / mirror / Atom feed
From: David Mosberger <davidm@napali.hpl.hp.com>
To: linux-ia64@vger.kernel.org
Subject: Re: [patch 2.6.10-rc3] Add TIF_SIGDELAYED processing
Date: Thu, 09 Dec 2004 01:22:27 +0000	[thread overview]
Message-ID: <16823.43219.609251.549622@napali.hpl.hp.com> (raw)
In-Reply-To: <15449.1102482344@kao1.melbourne.sgi.com>

>>>>> On Wed, 08 Dec 2004 16:05:44 +1100, Keith Owens <kaos@sgi.com> said:

  Keith> Some of the work on recoverable MCA events has a requirement
  Keith> to send a signal to a user process.  But it is not safe to
  Keith> send signals from MCA/INIT/NMI/PMI, because the rest of the
  Keith> kernel is an unknown state.  This patch adds set_sigdelayed()
  Keith> which is called from the problem contexts to set the delayed
  Keith> signal.  The delayed signal will be delivered from the right
  Keith> context on the next transition from kernel to user space.

  Keith> If TIF_SIGDELAYED is set when we run ia64_leave_kernel or
  Keith> ia64_leave_syscall then the delayed signal is delivered and
  Keith> cleared.  All code for sigdelayed processing is on the slow
  Keith> paths.

  Keith> A recoverable MCA handler that wants to kill a user task just
  Keith> does

  Keith>   set_sigdelayed(pid, signo, code, addr);

It seems rather dangerous to stash away PIDs and deliver signals to
them later on.  It's just an invitation for races, IMHO.

	--david

  parent reply	other threads:[~2004-12-09  1:22 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-12-08  5:05 [patch 2.6.10-rc3] Add TIF_SIGDELAYED processing Keith Owens
2004-12-08 17:11 ` Luck, Tony
2004-12-09  1:10 ` Keith Owens
2004-12-09  1:22 ` David Mosberger [this message]
2004-12-09  1:41 ` Keith Owens
2004-12-09 23:08 ` David Mosberger
2004-12-09 23:19 ` Luck, Tony
2004-12-09 23:22 ` David Mosberger
2004-12-10  0:28 ` Jesse Barnes
2004-12-10  1:21 ` Keith Owens

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=16823.43219.609251.549622@napali.hpl.hp.com \
    --to=davidm@napali.hpl.hp.com \
    --cc=linux-ia64@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox