1 // SPDX-License-Identifier: GPL-2.0
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>
11 int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
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;
18 if (!system_supports_address_auth() && !system_supports_generic_auth())
21 if (is_compat_thread(task_thread_info(tsk)))
25 ptrauth_keys_init_user(keys);
32 if (((arg & addr_key_mask) && !system_supports_address_auth()) ||
33 ((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth()))
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 ptrauth_keys_install_user(keys);
51 static u64 arg_to_enxx_mask(unsigned long arg)
53 u64 sctlr_enxx_mask = 0;
55 WARN_ON(arg & ~PR_PAC_ENABLED_KEYS_MASK);
56 if (arg & PR_PAC_APIAKEY)
57 sctlr_enxx_mask |= SCTLR_ELx_ENIA;
58 if (arg & PR_PAC_APIBKEY)
59 sctlr_enxx_mask |= SCTLR_ELx_ENIB;
60 if (arg & PR_PAC_APDAKEY)
61 sctlr_enxx_mask |= SCTLR_ELx_ENDA;
62 if (arg & PR_PAC_APDBKEY)
63 sctlr_enxx_mask |= SCTLR_ELx_ENDB;
64 return sctlr_enxx_mask;
67 int ptrauth_set_enabled_keys(struct task_struct *tsk, unsigned long keys,
68 unsigned long enabled)
72 if (!system_supports_address_auth())
75 if (is_compat_thread(task_thread_info(tsk)))
78 if ((keys & ~PR_PAC_ENABLED_KEYS_MASK) || (enabled & ~keys))
82 sctlr = tsk->thread.sctlr_user;
83 sctlr &= ~arg_to_enxx_mask(keys);
84 sctlr |= arg_to_enxx_mask(enabled);
85 tsk->thread.sctlr_user = sctlr;
87 update_sctlr_el1(sctlr);
93 int ptrauth_get_enabled_keys(struct task_struct *tsk)
97 if (!system_supports_address_auth())
100 if (is_compat_thread(task_thread_info(tsk)))
103 if (tsk->thread.sctlr_user & SCTLR_ELx_ENIA)
104 retval |= PR_PAC_APIAKEY;
105 if (tsk->thread.sctlr_user & SCTLR_ELx_ENIB)
106 retval |= PR_PAC_APIBKEY;
107 if (tsk->thread.sctlr_user & SCTLR_ELx_ENDA)
108 retval |= PR_PAC_APDAKEY;
109 if (tsk->thread.sctlr_user & SCTLR_ELx_ENDB)
110 retval |= PR_PAC_APDBKEY;