LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: S?bastien Dugu? <sebastien.dugue@bull.net>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	linux-aio <linux-aio@kvack.org>, Andrew Morton <akpm@osdl.org>,
	Suparna Bhattacharya <suparna@in.ibm.com>,
	Christoph Hellwig <hch@infradead.org>,
	Zach Brown <zach.brown@oracle.com>,
	Badari Pulavarty <pbadari@us.ibm.com>,
	Ulrich Drepper <drepper@redhat.com>,
	Jean Pierre Dion <jean-pierre.dion@bull.net>
Subject: Re: [PATCH -mm 3/5][AIO] - export good_sigevent()
Date: Wed, 29 Nov 2006 14:54:25 +0000	[thread overview]
Message-ID: <20061129145425.GA1953@infradead.org> (raw)
In-Reply-To: <20061129113234.38c12911@frecb000686>

> +/***
> + * good_sigevent - check and get target task from a sigevent.
> + * @event: the sigevent to be checked
> + *
> + * This function must be called with tasklist_lock held for reading.
> + */
> +struct task_struct * good_sigevent(sigevent_t * event)
> +{
> +	struct task_struct *rtn = current->group_leader;
> +
> +	if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
> +		(!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) ||
> +		 rtn->tgid != current->tgid ||
> +		 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
> +		return NULL;
> +
> +	if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
> +	    ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
> +		return NULL;
> +
> +	return rtn;
> +}

And while we're at it we should badly beat up the person that wrote this
mess in the first time.  To be somewhat readable it should look like:

static struct task_struct *good_sigevent(sigevent_t *event)
{
	struct task_struct *task = current->group_leader;

	if ((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
		if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
			return NULL;
	}

	if (event->sigev_notify & SIGEV_THREAD_ID) {
		if ((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)
			return NULL;
		task = find_task_by_pid(event->sigev_notify_thread_id);
		if (!task || task->tgid != current->tgid)
			return NULL;
	}

	return task;
}

And btw, looking at its currentl caller I see why we need the PF_EXITING
flag I recommended to remove easiler on, it even has a big comment that
we should copy & paste to aio.c aswell.  Still no idea why it's doing
the selectiv reference grabbing, though.

  parent reply	other threads:[~2006-11-29 14:54 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-11-29 10:24 [PATCH -mm 0/5][AIO] - AIO completion signal notification v3 Sébastien Dugué
2006-11-29 10:32 ` [PATCH -mm 1/5][AIO] - Rework compat_sys_io_submit Sébastien Dugué
2006-11-30  0:47   ` Zach Brown
2006-11-30  9:57     ` Sébastien Dugué
2006-11-30 17:27       ` Zach Brown
2006-11-29 10:32 ` [PATCH -mm 2/5][AIO] - fix aio.h includes Sébastien Dugué
2006-11-29 10:32 ` [PATCH -mm 3/5][AIO] - export good_sigevent() Sébastien Dugué
2006-11-29 10:38   ` Christoph Hellwig
2006-11-29 10:46     ` Sébastien Dugué
2006-11-29 14:54   ` Christoph Hellwig [this message]
2006-11-29 16:10     ` Sébastien Dugué
2006-12-04 17:13   ` Bharata B Rao
2006-12-05  8:30     ` Sébastien Dugué
2006-11-29 10:33 ` [PATCH -mm 4/5][AIO] - AIO completion signal notification Sébastien Dugué
2006-11-29 10:51   ` Christoph Hellwig
2006-11-29 13:08     ` Sébastien Dugué
2006-11-29 13:50       ` Christoph Hellwig
2006-11-29 14:18         ` Sébastien Dugué
2006-11-29 11:33   ` Jakub Jelinek
2006-11-29 13:25     ` Sébastien Dugué
2006-11-29 10:33 ` [PATCH -mm 5/5][AIO] - Listio support Sébastien Dugué
2006-11-30  8:25   ` Suparna Bhattacharya
2006-11-30 10:04     ` Sébastien Dugué

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=20061129145425.GA1953@infradead.org \
    --to=hch@infradead.org \
    --cc=akpm@osdl.org \
    --cc=drepper@redhat.com \
    --cc=jean-pierre.dion@bull.net \
    --cc=linux-aio@kvack.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbadari@us.ibm.com \
    --cc=sebastien.dugue@bull.net \
    --cc=suparna@in.ibm.com \
    --cc=zach.brown@oracle.com \
    --subject='Re: [PATCH -mm 3/5][AIO] - export good_sigevent()' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).