linux-kernel - Re: [PATCH 3/4 V2] futex: free_pi_state outside of hb->lock sections

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4C37A8FA.2020607@us.ibm.com>
Date:	Fri, 09 Jul 2010 15:55:54 -0700
From:	Darren Hart <dvhltc@...ibm.com>
To:	Darren Hart <dvhltc@...ibm.com>
CC:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...e.hu>,
	Eric Dumazet <eric.dumazet@...il.com>,
	John Kacur <jkacur@...hat.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Mike Galbraith <efault@....de>, linux-rt-users@...r.kernel.org
Subject: Re: [PATCH 3/4 V2] futex: free_pi_state outside of hb->lock sections

Apologies, mangled a rebase and this patch had bits of 4/4 in it.
Corrected below:


>From f40b8e684df6ed2b1ba9167cad3922ab43f4a717 Mon Sep 17 00:00:00 2001
From: Darren Hart <dvhltc@...ibm.com>
Date: Fri, 9 Jul 2010 17:07:10 -0400
Subject: [PATCH 3/4 V2] futex: free_pi_state outside of hb->lock sections

free_pi_state() calls kfree() and might sleep. To prepare for raw hb->locks,
get the calls to free_pi_state() out of the hb->lock() sections.

Signed-off-by: Darren Hart <dvhltc@...ibm.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Eric Dumazet <eric.dumazet@...il.com>
Cc: John Kacur <jkacur@...hat.com>
Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Mike Galbraith <efault@....de>
---
 kernel/futex.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index a6cec32..2cd58a2 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1339,7 +1339,6 @@ retry_private:
 			} else if (ret) {
 				/* -EDEADLK */
 				this->pi_state = NULL;
-				free_pi_state(pi_state);
 				goto out_unlock;
 			}
 		}
@@ -1483,16 +1482,19 @@ retry:
  */
 static void unqueue_me_pi(struct futex_q *q)
 {
+	struct futex_pi_state *pi_state = NULL;
+
 	WARN_ON(plist_node_empty(&q->list));
 	plist_del(&q->list, &q->list.plist);
 
 	BUG_ON(!q->pi_state);
-	free_pi_state(q->pi_state);
+	pi_state = q->pi_state;
 	q->pi_state = NULL;
 
 	spin_unlock(q->lock_ptr);
-
 	drop_futex_key_refs(&q->key);
+
+	free_pi_state(pi_state);
 }
 
 /*
-- 
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/