// SPDX-License-Identifier: GPL-2.0 #include <linux/compat.h>#include <linux/errno.h>#include <linux/prctl.h>#include <linux/random.h>#include <linux/sched.h>#include <asm/cpufeature.h>#include <asm/pointer_auth.h> int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg){	struct ptrauth_keys_user *keys = &tsk->thread.keys_user;	unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |				      PR_PAC_APDAKEY | PR_PAC_APDBKEY;	unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY; 	if (!system_supports_address_auth() && !system_supports_generic_auth())		return -EINVAL; 	if (is_compat_thread(task_thread_info(tsk)))		return -EINVAL; 	if (!arg) {		ptrauth_keys_init_user(keys);		return 0;	} 	if (arg & ~key_mask)		return -EINVAL; 	if (((arg & addr_key_mask) && !system_supports_address_auth()) ||	    ((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth()))		return -EINVAL; 	if (arg & PR_PAC_APIAKEY)		get_random_bytes(&keys->apia, sizeof(keys->apia));	if (arg & PR_PAC_APIBKEY)		get_random_bytes(&keys->apib, sizeof(keys->apib));	if (arg & PR_PAC_APDAKEY)		get_random_bytes(&keys->apda, sizeof(keys->apda));	if (arg & PR_PAC_APDBKEY)		get_random_bytes(&keys->apdb, sizeof(keys->apdb));	if (arg & PR_PAC_APGAKEY)		get_random_bytes(&keys->apga, sizeof(keys->apga));	ptrauth_keys_install_user(keys); 	return 0;} static u64 arg_to_enxx_mask(unsigned long arg){	u64 sctlr_enxx_mask = 0; 	WARN_ON(arg & ~PR_PAC_ENABLED_KEYS_MASK);	if (arg & PR_PAC_APIAKEY)		sctlr_enxx_mask |= SCTLR_ELx_ENIA;	if (arg & PR_PAC_APIBKEY)		sctlr_enxx_mask |= SCTLR_ELx_ENIB;	if (arg & PR_PAC_APDAKEY)		sctlr_enxx_mask |= SCTLR_ELx_ENDA;	if (arg & PR_PAC_APDBKEY)		sctlr_enxx_mask |= SCTLR_ELx_ENDB;	return sctlr_enxx_mask;} int ptrauth_set_enabled_keys(struct task_struct *tsk, unsigned long keys,			     unsigned long enabled){	u64 sctlr; 	if (!system_supports_address_auth())		return -EINVAL; 	if (is_compat_thread(task_thread_info(tsk)))		return -EINVAL; 	if ((keys & ~PR_PAC_ENABLED_KEYS_MASK) || (enabled & ~keys))		return -EINVAL; 	preempt_disable();	sctlr = tsk->thread.sctlr_user;	sctlr &= ~arg_to_enxx_mask(keys);	sctlr |= arg_to_enxx_mask(enabled);	tsk->thread.sctlr_user = sctlr;	if (tsk == current)		update_sctlr_el1(sctlr);	preempt_enable(); 	return 0;} int ptrauth_get_enabled_keys(struct task_struct *tsk){	int retval = 0; 	if (!system_supports_address_auth())		return -EINVAL; 	if (is_compat_thread(task_thread_info(tsk)))		return -EINVAL; 	if (tsk->thread.sctlr_user & SCTLR_ELx_ENIA)		retval |= PR_PAC_APIAKEY;	if (tsk->thread.sctlr_user & SCTLR_ELx_ENIB)		retval |= PR_PAC_APIBKEY;	if (tsk->thread.sctlr_user & SCTLR_ELx_ENDA)		retval |= PR_PAC_APDAKEY;	if (tsk->thread.sctlr_user & SCTLR_ELx_ENDB)		retval |= PR_PAC_APDBKEY; 	return retval;}