Kristina Martsenko | ba83088 | 2018-12-07 18:39:28 +0000 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | #include <linux/errno.h> |
| 4 | #include <linux/prctl.h> |
| 5 | #include <linux/random.h> |
| 6 | #include <linux/sched.h> |
| 7 | #include <asm/cpufeature.h> |
| 8 | #include <asm/pointer_auth.h> |
| 9 | |
| 10 | int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg) |
| 11 | { |
Will Deacon | 8493132 | 2018-12-13 13:14:06 +0000 | [diff] [blame] | 12 | struct ptrauth_keys *keys = &tsk->thread.keys_user; |
Kristina Martsenko | ba83088 | 2018-12-07 18:39:28 +0000 | [diff] [blame] | 13 | unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY | |
| 14 | PR_PAC_APDAKEY | PR_PAC_APDBKEY; |
| 15 | unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY; |
| 16 | |
| 17 | if (!system_supports_address_auth() && !system_supports_generic_auth()) |
| 18 | return -EINVAL; |
| 19 | |
| 20 | if (!arg) { |
| 21 | ptrauth_keys_init(keys); |
| 22 | ptrauth_keys_switch(keys); |
| 23 | return 0; |
| 24 | } |
| 25 | |
| 26 | if (arg & ~key_mask) |
| 27 | return -EINVAL; |
| 28 | |
| 29 | if (((arg & addr_key_mask) && !system_supports_address_auth()) || |
| 30 | ((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth())) |
| 31 | return -EINVAL; |
| 32 | |
| 33 | if (arg & PR_PAC_APIAKEY) |
| 34 | get_random_bytes(&keys->apia, sizeof(keys->apia)); |
| 35 | if (arg & PR_PAC_APIBKEY) |
| 36 | get_random_bytes(&keys->apib, sizeof(keys->apib)); |
| 37 | if (arg & PR_PAC_APDAKEY) |
| 38 | get_random_bytes(&keys->apda, sizeof(keys->apda)); |
| 39 | if (arg & PR_PAC_APDBKEY) |
| 40 | get_random_bytes(&keys->apdb, sizeof(keys->apdb)); |
| 41 | if (arg & PR_PAC_APGAKEY) |
| 42 | get_random_bytes(&keys->apga, sizeof(keys->apga)); |
| 43 | |
| 44 | ptrauth_keys_switch(keys); |
| 45 | |
| 46 | return 0; |
| 47 | } |