LXR linux/arch/arm64/kernel/pointer

   1// SPDX-License-Identifier: GPL-2.0
   2
   3#include <linux/compat.h>
   4#include <linux/errno.h>
   5#include <linux/prctl.h>
   6#include <linux/random.h>
   7#include <linux/sched.h>
   8#include <asm/cpufeature.h>
   9#include <asm/pointer_auth.h>
  10
  11int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
  12{
  13        struct ptrauth_keys_user *keys = &tsk->thread.keys_user;
  14        unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |
  15                                      PR_PAC_APDAKEY | PR_PAC_APDBKEY;
  16        unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY;
  17
  18        if (!system_supports_address_auth() && !system_supports_generic_auth())
  19                return -EINVAL;
  20
  21        if (is_compat_thread(task_thread_info(tsk)))
  22                return -EINVAL;
  23
  24        if (!arg) {
  25                ptrauth_keys_init_user(keys);
  26                return 0;
  27        }
  28
  29        if (arg & ~key_mask)
  30                return -EINVAL;
  31
  32        if (((arg & addr_key_mask) && !system_supports_address_auth()) ||
  33            ((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth()))
  34                return -EINVAL;
  35
  36        if (arg & PR_PAC_APIAKEY)
  37                get_random_bytes(&keys->apia, sizeof(keys->apia));
  38        if (arg & PR_PAC_APIBKEY)
  39                get_random_bytes(&keys->apib, sizeof(keys->apib));
  40        if (arg & PR_PAC_APDAKEY)
  41                get_random_bytes(&keys->apda, sizeof(keys->apda));
  42        if (arg & PR_PAC_APDBKEY)
  43                get_random_bytes(&keys->apdb, sizeof(keys->apdb));
  44        if (arg & PR_PAC_APGAKEY)
  45                get_random_bytes(&keys->apga, sizeof(keys->apga));
  46
  47        return 0;
  48}
  49