xref: /freebsd/sys/arm64/arm64/sys_machdep.c (revision 783d3ff6)
1 /*-
2  * Copyright (c) 2015 The FreeBSD Foundation
3  *
4  * This software was developed by Andrew Turner under
5  * sponsorship from the FreeBSD Foundation.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/proc.h>
33 #include <sys/sysproto.h>
34 
35 #include <vm/vm.h>
36 #include <vm/pmap.h>
37 #include <vm/vm_map.h>
38 
39 #include <machine/sysarch.h>
40 #include <machine/vmparam.h>
41 
42 int
43 sysarch(struct thread *td, struct sysarch_args *uap)
44 {
45 	struct arm64_guard_page_args gp_args;
46 	vm_offset_t eva;
47 	int error;
48 
49 	switch (uap->op) {
50 	case ARM64_GUARD_PAGE:
51 		error = copyin(uap->parms, &gp_args, sizeof(gp_args));
52 		if (error != 0)
53 			return (error);
54 
55 		/* Only accept canonical addresses, no PAC or TBI */
56 		if (!ADDR_IS_CANONICAL(gp_args.addr))
57 			return (EINVAL);
58 
59 		eva = gp_args.addr + gp_args.len;
60 
61 		/* Check for a length overflow */
62 		if (gp_args.addr > eva)
63 			return (EINVAL);
64 
65 		/* Check in the correct address space */
66 		if (eva >= VM_MAX_USER_ADDRESS)
67 			return (EINVAL);
68 
69 		/* Nothing to do */
70 		if (gp_args.len == 0)
71 			return (0);
72 
73 		error = pmap_bti_set(vmspace_pmap(td->td_proc->p_vmspace),
74 		    trunc_page(gp_args.addr), round_page(eva));
75 		break;
76 	default:
77 		error = EINVAL;
78 		break;
79 	}
80 
81 	return (error);
82 }
83