arch/powerpc/mm/nohash/kup.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * This file contains the routines for initializing kernel userspace protection
   4  */
   5
   6 #include <linux/export.h>
   7 #include <linux/init.h>
   8 #include <linux/printk.h>
   9 #include <linux/smp.h>
  10
  11 #include <asm/kup.h>
  12 #include <asm/smp.h>
  13
  14 #ifdef CONFIG_PPC_KUAP
  15 void setup_kuap(bool disabled)
  16 {
  17         if (disabled) {
  18                 if (IS_ENABLED(CONFIG_40x))
  19                         disable_kuep = true;
  20                 if (smp_processor_id() == boot_cpuid)
  21                         cur_cpu_spec->mmu_features &= ~MMU_FTR_KUAP;
  22                 return;
  23         }
  24
  25         pr_info("Activating Kernel Userspace Access Protection\n");
  26
  27         prevent_user_access(KUAP_READ_WRITE);
  28 }
  29 #endif