Patchwork [6/6] ACPI / Battery: Resolve the race condition in the sysfs_remove_battery()

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Submitter lan,Tianyu
Date June 29, 2011, 8:25 a.m.
Message ID <1309335912-26625-1-git-send-email-tianyu.lan@intel.com>
Download mbox | patch
Permalink /patch/927612/
State New, archived
Headers show

Comments

lan,Tianyu - June 29, 2011, 8:25 a.m.
Use battery->lock in sysfs_remove_battery() to make
checking, removing, and clearing bat.dev atomic.
This is necessary because sysfs_remove_battery() may
be invoked concurrently from different paths.
	https://bugzilla.kernel.org/show_bug.cgi?id=35642

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 drivers/acpi/battery.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

Patch

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index cb4a554..123adee 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -573,11 +573,16 @@  static int sysfs_add_battery(struct acpi_battery *battery)
 
 static void sysfs_remove_battery(struct acpi_battery *battery)
 {
-	if (!battery->bat.dev)
+	mutex_lock(&battery->lock);
+	if (!battery->bat.dev) { 
+		mutex_unlock(&battery->lock);
 		return;
+	}		
+	      
 	device_remove_file(battery->bat.dev, &alarm_attr);
 	power_supply_unregister(&battery->bat);
 	battery->bat.dev = NULL;
+	mutex_unlock(&battery->lock);
 }
 
 /*