mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Brian Silverman <bsilver16384@gmail.com>
Cc: austin.linux@gmail.com, linux-kernel@vger.kernel.org,
	darren@dvhart.com, peterz@infradead.org
Subject: Re: [PATCH v2] futex: fix a race condition between REQUEUE_PI and task death
Date: Sun, 26 Oct 2014 16:04:53 +0100 (CET)	[thread overview]
Message-ID: <alpine.DEB.2.11.1410261601060.5308@nanos> (raw)
In-Reply-To: <1414282837-23092-1-git-send-email-bsilver16384@gmail.com>

On Sat, 25 Oct 2014, Brian Silverman wrote:
> @@ -64,6 +64,7 @@
>  #include <linux/hugetlb.h>
>  #include <linux/freezer.h>
>  #include <linux/bootmem.h>
> +#include <linux/lockdep.h>

Already included.
  
>   * PI futexes can not be requeued and must remove themself from the
>   * hash bucket. The hash bucket lock (i.e. lock_ptr) is held on entry
>   * and dropped here.
> + * Must be called with the hb lock held.

It's already required that the hb lock, i.e. q->lock_ptr is held on
entry. So there is no point for adding hb to the interface. We rather
add "struct spin_lock *lock" to free_pi_state() and hand in
q->lock_ptr from here and &hb2->lock from requeue_pi.

I take the immediate bugfix and strip out this debug stuff for
now. Care to resend this part?

Thanks,

	tglx

  parent reply	other threads:[~2014-10-26 15:04 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-23 19:22 [PATCH] " Brian Silverman
2014-10-23 19:28 ` Brian Silverman
2014-10-24  5:25   ` Mike Galbraith
2014-10-30  4:28   ` Darren Hart
2014-10-30  5:18     ` Mike Galbraith
2014-10-25 19:29 ` Thomas Gleixner
2014-10-26  0:19   ` Brian Silverman
2014-10-26 14:29     ` Thomas Gleixner
2014-10-26  0:20 ` [PATCH v2] " Brian Silverman
2014-10-26  6:22   ` Mike Galbraith
2014-10-26 14:45   ` Thomas Gleixner
2014-10-26 15:04   ` Thomas Gleixner [this message]
2014-10-26 15:22   ` [tip:locking/urgent] futex: Fix " tip-bot for Brian Silverman

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=alpine.DEB.2.11.1410261601060.5308@nanos \
    --to=tglx@linutronix.de \
    --cc=austin.linux@gmail.com \
    --cc=bsilver16384@gmail.com \
    --cc=darren@dvhart.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peterz@infradead.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
all inboxes | Powered by JetHome®