Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH] ACPI / dock: Take ACPI scan lock in write_undock() | Date | Sun, 16 Jun 2013 00:16:31 +0200 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since commit 3757b94 (ACPI / hotplug: Fix concurrency issues and memory leaks) acpi_bus_scan() and acpi_bus_trim() must always be called under acpi_scan_lock, but currently the following scenario violating that requirement is possible:
write_undock() handle_eject_request() hotplug_dock_devices() dock_remove_acpi_device() acpi_bus_trim()
Fix that by making write_undock() acquire acpi_scan_lock before calling handle_eject_request() as appropriate (begin_undock() is under the lock too in analogy with acpi_dock_deferred_cb()).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: 3.9+ <stable@vger.kernel.org> --- drivers/acpi/dock.c | 2 ++ 1 file changed, 2 insertions(+)
Index: linux-pm/drivers/acpi/dock.c =================================================================== --- linux-pm.orig/drivers/acpi/dock.c +++ linux-pm/drivers/acpi/dock.c @@ -868,8 +868,10 @@ static ssize_t write_undock(struct devic if (!count) return -EINVAL; + acpi_scan_lock_acquire(); begin_undock(dock_station); ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST); + acpi_scan_lock_release(); return ret ? ret: count; } static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
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