cloudabi64_sysvec.c revision 316570 
1/*-
2 * Copyright (c) 2015 Nuxi, https://nuxi.nl/
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD: stable/11/sys/arm64/cloudabi64/cloudabi64_sysvec.c 316570 2017-04-06 13:51:54Z ed $");
28
29#include <sys/param.h>
30#include <sys/imgact.h>
31#include <sys/kernel.h>
32#include <sys/proc.h>
33#include <sys/sysent.h>
34
35#include <vm/vm.h>
36#include <vm/pmap.h>
37
38#include <machine/frame.h>
39#include <machine/pcb.h>
40#include <machine/vmparam.h>
41
42#include <compat/cloudabi/cloudabi_util.h>
43
44#include <compat/cloudabi64/cloudabi64_syscall.h>
45#include <compat/cloudabi64/cloudabi64_util.h>
46
47extern const char *cloudabi64_syscallnames[];
48extern struct sysent cloudabi64_sysent[];
49
50static void
51cloudabi64_proc_setregs(struct thread *td, struct image_params *imgp,
52    unsigned long stack)
53{
54	struct trapframe *regs;
55
56	exec_setregs(td, imgp, stack);
57
58	/*
59	 * The stack now contains a pointer to the TCB and the auxiliary
60	 * vector. Let x0 point to the auxiliary vector, and set
61	 * tpidr_el0 to the TCB.
62	 */
63	regs = td->td_frame;
64	regs->tf_x[0] = td->td_retval[0] =
65	    stack + roundup(sizeof(cloudabi64_tcb_t), sizeof(register_t));
66	(void)cpu_set_user_tls(td, (void *)stack);
67}
68
69static int
70cloudabi64_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
71{
72	struct trapframe *frame = td->td_frame;
73	int i;
74
75	/* Obtain system call number. */
76	sa->code = frame->tf_x[8];
77	if (sa->code >= CLOUDABI64_SYS_MAXSYSCALL)
78		return (ENOSYS);
79	sa->callp = &cloudabi64_sysent[sa->code];
80	sa->narg = sa->callp->sy_narg;
81
82	/* Fetch system call arguments. */
83	for (i = 0; i < MAXARGS; i++)
84		sa->args[i] = frame->tf_x[i];
85
86	/* Default system call return values. */
87	td->td_retval[0] = 0;
88	td->td_retval[1] = frame->tf_x[1];
89	return (0);
90}
91
92static void
93cloudabi64_set_syscall_retval(struct thread *td, int error)
94{
95	struct trapframe *frame = td->td_frame;
96
97	switch (error) {
98	case 0:
99		/* System call succeeded. */
100		frame->tf_x[0] = td->td_retval[0];
101		frame->tf_x[1] = td->td_retval[1];
102		frame->tf_spsr &= ~PSR_C;
103		break;
104	case ERESTART:
105		/* Restart system call. */
106		frame->tf_elr -= 4;
107		break;
108	case EJUSTRETURN:
109		break;
110	default:
111		/* System call returned an error. */
112		frame->tf_x[0] = cloudabi_convert_errno(error);
113		frame->tf_spsr |= PSR_C;
114		break;
115	}
116}
117
118static void
119cloudabi64_schedtail(struct thread *td)
120{
121	struct trapframe *frame = td->td_frame;
122
123	/*
124	 * Initial register values for processes returning from fork.
125	 * Make sure that we only set these values when forking, not
126	 * when creating a new thread.
127	 */
128	if ((td->td_pflags & TDP_FORKING) != 0) {
129		frame->tf_x[0] = CLOUDABI_PROCESS_CHILD;
130		frame->tf_x[1] = td->td_tid;
131	}
132}
133
134int
135cloudabi64_thread_setregs(struct thread *td,
136    const cloudabi64_threadattr_t *attr, uint64_t tcb)
137{
138	struct trapframe *frame;
139	stack_t stack;
140
141	/* Perform standard register initialization. */
142	stack.ss_sp = TO_PTR(attr->stack);
143	stack.ss_size = attr->stack_size;
144	cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack);
145
146	/*
147	 * Pass in the thread ID of the new thread and the argument
148	 * pointer provided by the parent thread in as arguments to the
149	 * entry point.
150	 */
151	frame = td->td_frame;
152	frame->tf_x[0] = td->td_tid;
153	frame->tf_x[1] = attr->argument;
154
155	/* Set up TLS. */
156	return (cpu_set_user_tls(td, (void *)tcb));
157}
158
159static struct sysentvec cloudabi64_elf_sysvec = {
160	.sv_size		= CLOUDABI64_SYS_MAXSYSCALL,
161	.sv_table		= cloudabi64_sysent,
162	.sv_fixup		= cloudabi64_fixup,
163	.sv_name		= "CloudABI ELF64",
164	.sv_coredump		= elf64_coredump,
165	.sv_pagesize		= PAGE_SIZE,
166	.sv_minuser		= VM_MIN_ADDRESS,
167	.sv_maxuser		= VM_MAXUSER_ADDRESS,
168	.sv_stackprot		= VM_PROT_READ | VM_PROT_WRITE,
169	.sv_copyout_strings	= cloudabi64_copyout_strings,
170	.sv_setregs		= cloudabi64_proc_setregs,
171	.sv_flags		= SV_ABI_CLOUDABI | SV_CAPSICUM | SV_LP64,
172	.sv_set_syscall_retval	= cloudabi64_set_syscall_retval,
173	.sv_fetch_syscall_args	= cloudabi64_fetch_syscall_args,
174	.sv_syscallnames	= cloudabi64_syscallnames,
175	.sv_schedtail		= cloudabi64_schedtail,
176};
177
178INIT_SYSENTVEC(elf_sysvec, &cloudabi64_elf_sysvec);
179
180Elf64_Brandinfo cloudabi64_brand = {
181	.brand		= ELFOSABI_CLOUDABI,
182	.machine	= EM_AARCH64,
183	.sysvec		= &cloudabi64_elf_sysvec,
184	.flags		= BI_CAN_EXEC_DYN,
185};
186