ACPI: TAD: Add locking around AML evaluations

In the ACPI TAD driver, there are hidden assumptions that the ACPI
control methods used by it will not be evaluated concurrently due
to ACPICA namespace and interpreter locking.

However, that may not be the case since ACPICA may drop and re-acquire
the namespace and interpreter locks during the evaluation of a given
object in a few cases, including the one in which the AML in question
sleeps causing acpi_ex_system_do_sleep() to be called.  In that case,
the evaluation of one control method may be started while the
evaluation of another one is still in progress.

For this reason, add a global lock to the ACPI TAD driver and
acquire it every time before evaluating an ACPI control method,
except for the initial evaluation of _GCP in acpi_tad_probe().

Fixes: 95c513ec84f7 ("ACPI: Add Time and Alarm Device (TAD) driver")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/12951141.O9o76ZdvQC@rafael.j.wysocki

0 files changed, 0 insertions, 0 deletions