linux-kernel - [PATCH] PM: Prevent waiting forever on asynchronous suspend after abort

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: <1340208795-8049-1-git-send-email-msb@chromium.org>
Date:	Wed, 20 Jun 2012 09:13:15 -0700
From:	mandeep.baines@...il.com
To:	linux-kernel@...r.kernel.org, "Rafael J. Wysocki" <rjw@...k.pl>
Cc:	Mandeep Singh Baines <msb@...omium.org>, linux-pm@...r.kernel.org,
	stable@...nel.org, Pavel Machek <pavel@....cz>,
	Len Brown <len.brown@...el.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Kevin Hilman <khilman@...com>,
	Alan Stern <stern@...land.harvard.edu>,
	Colin Cross <ccross@...roid.com>,
	Sameer Nanda <snanda@...omium.org>,
	Olof Johansson <olofj@...omium.org>
Subject: [PATCH] PM: Prevent waiting forever on asynchronous suspend after abort

From: Mandeep Singh Baines <msb@...omium.org>

__device_suspend() must always send a completion. Otherwise, parent
devices will wait forever.

Commit 1e2ef05b, "PM: Limit race conditions between runtime PM and
system sleep (v2)", introduced a regression by short-circuiting the
complete_all() for certain error cases.

This patch fixes the bug by always signalling a completion.

Addresses http://crosbug.com/31972

Tested by injecting an abort.

Signed-off-by: Mandeep Singh Baines <msb@...omium.org>
Cc: Rafael J. Wysocki <rjw@...k.pl>
Cc: linux-pm@...r.kernel.org
Cc: stable@...nel.org
Cc: Pavel Machek <pavel@....cz>
Cc: Len Brown <len.brown@...el.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Kevin Hilman <khilman@...com>
Cc: Alan Stern <stern@...land.harvard.edu>
Cc: Colin Cross <ccross@...roid.com>
Cc: Sameer Nanda <snanda@...omium.org>
Cc: Olof Johansson <olofj@...omium.org>
---
 drivers/base/power/main.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index e0fb5b0..9cb845e 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1031,7 +1031,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	dpm_wait_for_children(dev, async);
 
 	if (async_error)
-		return 0;
+		goto Complete;
 
 	pm_runtime_get_noresume(dev);
 	if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
@@ -1040,7 +1040,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	if (pm_wakeup_pending()) {
 		pm_runtime_put_sync(dev);
 		async_error = -EBUSY;
-		return 0;
+		goto Complete;
 	}
 
 	device_lock(dev);
@@ -1097,6 +1097,8 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	}
 
 	device_unlock(dev);
+
+ Complete:
 	complete_all(&dev->power.completion);
 
 	if (error) {
-- 
1.7.3.4

--
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/