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 { 12 struct ptrauth_keys *keys = &tsk->thread.keys_user; 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 } 48