ACPICA: Namespace: Fix deadlock triggered by MLC support in dynamic table loading

The new module-level code (MLC) approach invokes MLC on the per-table
basis, but the dynamic loading support of this is incorrect because
of the lock order:

 acpi_ns_evaluate
   acpi_ex_enter_intperter
     acpi_ns_load_table (triggered by Load opcode)
       acpi_ns_exec_module_code_list
         acpi_ex_enter_intperter

The regression is introduced by the following commit:

  Commit: 2785ce8d0da1cac9d8f78615e116cf929e9a9123
  ACPICA Commit: 071eff738c59eda1792ac24b3b688b61691d7e7c
  Subject: ACPICA: Add per-table execution of module-level code

This patch fixes this regression by unlocking the interpreter lock
before invoking MLC.  However, the unlocking is done to the
acpi_ns_load_table(), in which the interpreter lock should be locked
by acpi_ns_parse_table() but it wasn't.

Fixes: 2785ce8d0da1 (ACPICA: Add per-table execution of module-level code)
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
[ rjw : Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

path: root/privs.h

#ifndef PRIVS_H
#define PRIVS_H

#include <stdbool.h>

extern void drop_privileges(bool enforce, uid_t uid, gid_t gid);

#endif /* PRIVS_H */