xref: /freebsd/sys/arm64/arm64/sys_machdep.c (revision 3bd4724794a5e5838f09420a615227416d6b2903)
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/sysctl.h>
34 #include <sys/sysproto.h>
35 
36 #include <vm/vm.h>
37 #include <vm/pmap.h>
38 #include <vm/vm_map.h>
39 
40 #include <machine/pcb.h>
41 #include <machine/sysarch.h>
42 #include <machine/vmparam.h>
43 
44 #include <security/audit/audit.h>
45 
46 int
sysarch(struct thread * td,struct sysarch_args * uap)47 sysarch(struct thread *td, struct sysarch_args *uap)
48 {
49 	struct arm64_guard_page_args gp_args;
50 	struct pcb *pcb;
51 	vm_offset_t eva;
52 	unsigned long sve_len;
53 	int error;
54 
55 	switch (uap->op) {
56 	case ARM64_GUARD_PAGE:
57 		error = copyin(uap->parms, &gp_args, sizeof(gp_args));
58 		if (error != 0)
59 			return (error);
60 
61 		/* Only accept canonical addresses, no PAC or TBI */
62 		if (!ADDR_IS_CANONICAL(gp_args.addr))
63 			return (EINVAL);
64 
65 		eva = gp_args.addr + gp_args.len;
66 
67 		/* Check for a length overflow */
68 		if (gp_args.addr > eva)
69 			return (EINVAL);
70 
71 		/* Check in the correct address space */
72 		if (eva >= VM_MAX_USER_ADDRESS)
73 			return (EINVAL);
74 
75 		/* Nothing to do */
76 		if (gp_args.len == 0)
77 			return (0);
78 
79 		error = pmap_bti_set(vmspace_pmap(td->td_proc->p_vmspace),
80 		    trunc_page(gp_args.addr), round_page(eva));
81 		break;
82 	case ARM64_GET_SVE_VL:
83 		pcb = td->td_pcb;
84 		sve_len = pcb->pcb_sve_len;
85 		error = EINVAL;
86 		if (sve_len != 0)
87 			error = copyout(&sve_len, uap->parms, sizeof(sve_len));
88 		break;
89 	default:
90 		error = EINVAL;
91 		break;
92 	}
93 
94 	return (error);
95 }
96 
97 bool arm64_pid_in_contextidr = false;
98 SYSCTL_BOOL(_machdep, OID_AUTO, pid_in_contextidr, CTLFLAG_RW,
99     &arm64_pid_in_contextidr, false,
100     "Save PID into CONTEXTIDR_EL1 register on context switch");
101