1 // SPDX-License-Identifier: GPL-2.0-only
86 	 * tagged, return non-zero to avoid KSM merging. If only one of the  in memcmp_pages()
96 static inline void __mte_enable_kernel(const char *mode, unsigned long tcf)  in __mte_enable_kernel()  argument
98 	/* Enable MTE Sync Mode for EL1. */  in __mte_enable_kernel()
103 	pr_info_once("MTE: enabled in %s mode at EL1\n", mode);  in __mte_enable_kernel()
110 	 * Make sure we enter this function when no PE has set  in mte_enable_kernel_sync()
111 	 * async mode previously.  in mte_enable_kernel_sync()
114 			"MTE async mode enabled system wide!");  in mte_enable_kernel_sync()
124 	 * MTE async mode is set system wide by the first PE that  in mte_enable_kernel_async()
128 	 * mode in between sync and async, this strategy needs  in mte_enable_kernel_async()
141 		 * MTE asymm mode behaves as async mode for store  in mte_enable_kernel_asymm()
142 		 * operations. The mode is set system wide by the  in mte_enable_kernel_asymm()
146 		 * mode in between sync and async, this strategy needs  in mte_enable_kernel_asymm()
153 		 * If the CPU does not support MTE asymmetric mode the  in mte_enable_kernel_asymm()
154 		 * kernel falls back on synchronous mode which is the  in mte_enable_kernel_asymm()
170 		 * because there is no indirect read subsequent to it  in mte_check_tfsr_el1()
171 		 * (per ARM DDI 0487F.c table D13-1).  in mte_check_tfsr_el1()
181  * This is where we actually resolve the system and process MTE mode
193 	unsigned long sctlr = task->thread.sctlr_user;  in mte_update_sctlr_user()
194 	unsigned long mte_ctrl = task->thread.mte_ctrl;  in mte_update_sctlr_user()
199 	 * If there is no overlap between the system preferred and  in mte_update_sctlr_user()
214 		sctlr |= SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF0, SYNC);  in mte_update_sctlr_user()
215 	task->thread.sctlr_user = sctlr;  in mte_update_sctlr_user()
221 	 * SYS_GCR_EL1 will be set to current->thread.mte_ctrl value by  in mte_update_gcr_excl()
228 		((task->thread.mte_ctrl >> MTE_CTRL_GCR_USER_EXCL_SHIFT) &  in mte_update_gcr_excl()
241 	BUG_ON(nr_inst != 1); /* Branch -> NOP */  in kasan_hw_tags_enable()
291 	 * CPU power-up.  in mte_cpu_setup()
309 	 * RGSR_EL1.SEED must be non-zero for IRG to produce  in mte_cpu_setup()
364 	 * If the system supports it and both sync and async modes are  in set_mte_ctrl()
365 	 * specified then implicitly enable asymmetric mode.  in set_mte_ctrl()
366 	 * Userspace could see a mix of both sync and async anyway due  in set_mte_ctrl()
374 	task->thread.mte_ctrl = mte_ctrl;  in set_mte_ctrl()
379 		update_sctlr_el1(task->thread.sctlr_user);  in set_mte_ctrl()
389 	u64 mte_ctrl = task->thread.mte_ctrl;  in get_mte_ctrl()
413 	void __user *buf = kiov->iov_base;  in __access_remote_tags()
414 	size_t len = kiov->iov_len;  in __access_remote_tags()
419 		return -EFAULT;  in __access_remote_tags()
422 		return -EIO;  in __access_remote_tags()
444 		if (!(vma->vm_flags & VM_MTE)) {  in __access_remote_tags()
445 			err = -EOPNOTSUPP;  in __access_remote_tags()
458 		tags = min(len, (PAGE_SIZE - offset) / MTE_GRANULE_SIZE);  in __access_remote_tags()
473 		len -= tags;  in __access_remote_tags()
479 	/* return an error if no tags copied */  in __access_remote_tags()
480 	kiov->iov_len = buf - kiov->iov_base;  in __access_remote_tags()
481 	if (!kiov->iov_len) {  in __access_remote_tags()
484 			return -EIO;  in __access_remote_tags()
486 			return -EFAULT;  in __access_remote_tags()
504 		return -EPERM;  in access_remote_tags()
506 	if (!tsk->ptrace || (current != tsk->parent) ||  in access_remote_tags()
508 	     !ptracer_capable(tsk, mm->user_ns))) {  in access_remote_tags()
510 		return -EPERM;  in access_remote_tags()
528 		return -EIO;  in mte_ptrace_copy_tags()
530 	if (get_user(kiov.iov_base, &uiov->iov_base) ||  in mte_ptrace_copy_tags()
531 	    get_user(kiov.iov_len, &uiov->iov_len))  in mte_ptrace_copy_tags()
532 		return -EFAULT;  in mte_ptrace_copy_tags()
542 		ret = put_user(kiov.iov_len, &uiov->iov_len);  in mte_ptrace_copy_tags()
550 	switch (per_cpu(mte_tcf_preferred, dev->id)) {  in mte_tcf_preferred_show()
554 		return sysfs_emit(buf, "sync\n");  in mte_tcf_preferred_show()
570 	else if (sysfs_streq(buf, "sync"))  in mte_tcf_preferred_store()
575 		return -EINVAL;  in mte_tcf_preferred_store()
578 	per_cpu(mte_tcf_preferred, dev->id) = tcf;  in mte_tcf_preferred_store()
626 	return end - uaddr;  in mte_probe_user_range()