cloudabi32_sysvec.c revision 316576
1/*-
2 * Copyright (c) 2015-2016 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/arm/cloudabi32/cloudabi32_sysvec.c 316576 2017-04-06 15:19:18Z kib $");
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/cloudabi32/cloudabi32_syscall.h>
45#include <compat/cloudabi32/cloudabi32_util.h>
46
47extern const char *cloudabi32_syscallnames[];
48extern struct sysent cloudabi32_sysent[];
49
50static void
51cloudabi32_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 r0 point to the auxiliary vector, and set
61	 * tpidrurw to the TCB.
62	 */
63	regs = td->td_frame;
64	regs->tf_r0 = td->td_retval[0] =
65	    stack + roundup(sizeof(cloudabi32_tcb_t), sizeof(register_t));
66	(void)cpu_set_user_tls(td, (void *)stack);
67}
68
69static int
70cloudabi32_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
71{
72	struct trapframe *frame = td->td_frame;
73	int error;
74
75	/* Obtain system call number. */
76	sa->code = frame->tf_r12;
77	if (sa->code >= CLOUDABI32_SYS_MAXSYSCALL)
78		return (ENOSYS);
79	sa->callp = &cloudabi32_sysent[sa->code];
80	sa->narg = sa->callp->sy_narg;
81
82	/* Fetch system call arguments from registers and the stack. */
83	sa->args[0] = frame->tf_r0;
84	sa->args[1] = frame->tf_r1;
85	sa->args[2] = frame->tf_r2;
86	sa->args[3] = frame->tf_r3;
87	if (sa->narg > 4) {
88		error = copyin((void *)td->td_frame->tf_usr_sp, &sa->args[4],
89		    (sa->narg - 4) * sizeof(register_t));
90		if (error != 0)
91			return (error);
92	}
93
94	/* Default system call return values. */
95	td->td_retval[0] = 0;
96	td->td_retval[1] = frame->tf_r1;
97	return (0);
98}
99
100static void
101cloudabi32_set_syscall_retval(struct thread *td, int error)
102{
103	struct trapframe *frame = td->td_frame;
104
105	switch (error) {
106	case 0:
107		/* System call succeeded. */
108		frame->tf_r0 = td->td_retval[0];
109		frame->tf_r1 = td->td_retval[1];
110		frame->tf_spsr &= ~PSR_C;
111		break;
112	case ERESTART:
113		/* Restart system call. */
114		frame->tf_pc -= 4;
115		break;
116	case EJUSTRETURN:
117		break;
118	default:
119		/* System call returned an error. */
120		frame->tf_r0 = cloudabi_convert_errno(error);
121		frame->tf_spsr |= PSR_C;
122		break;
123	}
124}
125
126static void
127cloudabi32_schedtail(struct thread *td)
128{
129	struct trapframe *frame = td->td_frame;
130
131	/*
132	 * Initial register values for processes returning from fork.
133	 * Make sure that we only set these values when forking, not
134	 * when creating a new thread.
135	 */
136	if ((td->td_pflags & TDP_FORKING) != 0) {
137		frame->tf_r0 = CLOUDABI_PROCESS_CHILD;
138		frame->tf_r1 = td->td_tid;
139	}
140}
141
142int
143cloudabi32_thread_setregs(struct thread *td,
144    const cloudabi32_threadattr_t *attr, uint32_t tcb)
145{
146	struct trapframe *frame;
147	stack_t stack;
148
149	/* Perform standard register initialization. */
150	stack.ss_sp = TO_PTR(attr->stack);
151	stack.ss_size = attr->stack_len;
152	cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack);
153
154	/*
155	 * Pass in the thread ID of the new thread and the argument
156	 * pointer provided by the parent thread in as arguments to the
157	 * entry point.
158	 */
159	frame = td->td_frame;
160	frame->tf_r0 = td->td_tid;
161	frame->tf_r1 = attr->argument;
162
163	/* Set up TLS. */
164	return (cpu_set_user_tls(td, (void *)tcb));
165}
166
167static struct sysentvec cloudabi32_elf_sysvec = {
168	.sv_size		= CLOUDABI32_SYS_MAXSYSCALL,
169	.sv_table		= cloudabi32_sysent,
170	.sv_fixup		= cloudabi32_fixup,
171	.sv_name		= "CloudABI ELF32",
172	.sv_coredump		= elf32_coredump,
173	.sv_pagesize		= PAGE_SIZE,
174	.sv_minuser		= VM_MIN_ADDRESS,
175	.sv_maxuser		= VM_MAXUSER_ADDRESS,
176	.sv_stackprot		= VM_PROT_READ | VM_PROT_WRITE,
177	.sv_copyout_strings	= cloudabi32_copyout_strings,
178	.sv_setregs		= cloudabi32_proc_setregs,
179	.sv_flags		= SV_ABI_CLOUDABI | SV_CAPSICUM | SV_ILP32,
180	.sv_set_syscall_retval	= cloudabi32_set_syscall_retval,
181	.sv_fetch_syscall_args	= cloudabi32_fetch_syscall_args,
182	.sv_syscallnames	= cloudabi32_syscallnames,
183	.sv_schedtail		= cloudabi32_schedtail,
184};
185
186INIT_SYSENTVEC(elf_sysvec, &cloudabi32_elf_sysvec);
187
188Elf32_Brandinfo cloudabi32_brand = {
189	.brand		= ELFOSABI_CLOUDABI,
190	.machine	= EM_ARM,
191	.sysvec		= &cloudabi32_elf_sysvec,
192	.flags		= BI_BRAND_ONLY_STATIC,
193};
194