forked from luck/tmp_suning_uos_patched
78ea4639a7
There is a slight possibility for the ACPI device object pointed to by adev in acpi_hotplug_notify_cb() to become invalid between the acpi_bus_get_device() that it comes from and the subsequent dereference of that pointer under get_device(). Namely, if acpi_scan_drop_device() runs in parallel with acpi_hotplug_notify_cb(), acpi_device_del_work_fn() queued up by it may delete the device object in question right after a successful execution of acpi_bus_get_device() in acpi_bus_notify(). An analogous problem is present in acpi_bus_notify() where the device pointer coming from acpi_bus_get_device() may become invalid before it subsequent dereference in the "if" block. To prevent that from happening, introduce a new function, acpi_bus_get_acpi_device(), working analogously to acpi_bus_get_device() except that it will grab a reference to the ACPI device object returned by it and it will do that under the ACPICA's namespace mutex. Then, make both acpi_hotplug_notify_cb() and acpi_bus_notify() use acpi_bus_get_acpi_device() instead of acpi_bus_get_device() so as to ensure that the pointers used by them will not become stale at one point. In addition to that, introduce acpi_bus_put_acpi_device() as a wrapper around put_device() to be used along with acpi_bus_get_acpi_device() and make the (new) users of the latter use acpi_bus_put_acpi_device() too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> |
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| .. | ||
| platform | ||
| acbuffer.h | ||
| acconfig.h | ||
| acexcep.h | ||
| acnames.h | ||
| acoutput.h | ||
| acpi_bus.h | ||
| acpi_drivers.h | ||
| acpi_io.h | ||
| acpi_numa.h | ||
| acpi.h | ||
| acpiosxf.h | ||
| acpixf.h | ||
| acrestyp.h | ||
| actbl1.h | ||
| actbl2.h | ||
| actbl3.h | ||
| actbl.h | ||
| actypes.h | ||
| apei.h | ||
| button.h | ||
| ghes.h | ||
| hed.h | ||
| pdc_intel.h | ||
| processor.h | ||
| reboot.h | ||
| video.h | ||