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("$FreeBSD$");
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 
47 extern const char *cloudabi64_syscallnames[];
48 extern struct sysent cloudabi64_sysent[];
49 
50 static void
cloudabi64_proc_setregs(struct thread * td,struct image_params * imgp,uintptr_t stack)51 cloudabi64_proc_setregs(struct thread *td, struct image_params *imgp,
52     uintptr_t 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] =
65 	    stack + roundup(sizeof(cloudabi64_tcb_t), sizeof(register_t));
66 	(void)cpu_set_user_tls(td, TO_PTR(stack));
67 }
68 
69 static int
cloudabi64_fetch_syscall_args(struct thread * td)70 cloudabi64_fetch_syscall_args(struct thread *td)
71 {
72 	struct trapframe *frame;
73 	struct syscall_args *sa;
74 	int i;
75 
76 	frame = td->td_frame;
77 	sa = &td->td_sa;
78 
79 	/* Obtain system call number. */
80 	sa->code = frame->tf_x[8];
81 	if (sa->code >= CLOUDABI64_SYS_MAXSYSCALL)
82 		return (ENOSYS);
83 	sa->callp = &cloudabi64_sysent[sa->code];
84 
85 	/* Fetch system call arguments. */
86 	for (i = 0; i < MAXARGS; i++)
87 		sa->args[i] = frame->tf_x[i];
88 
89 	/* Default system call return values. */
90 	td->td_retval[0] = 0;
91 	td->td_retval[1] = frame->tf_x[1];
92 	return (0);
93 }
94 
95 static void
cloudabi64_set_syscall_retval(struct thread * td,int error)96 cloudabi64_set_syscall_retval(struct thread *td, int error)
97 {
98 	struct trapframe *frame = td->td_frame;
99 
100 	switch (error) {
101 	case 0:
102 		/* System call succeeded. */
103 		frame->tf_x[0] = td->td_retval[0];
104 		frame->tf_x[1] = td->td_retval[1];
105 		frame->tf_spsr &= ~PSR_C;
106 		break;
107 	case ERESTART:
108 		/* Restart system call. */
109 		frame->tf_elr -= 4;
110 		break;
111 	case EJUSTRETURN:
112 		break;
113 	default:
114 		/* System call returned an error. */
115 		frame->tf_x[0] = cloudabi_convert_errno(error);
116 		frame->tf_spsr |= PSR_C;
117 		break;
118 	}
119 }
120 
121 static void
cloudabi64_schedtail(struct thread * td)122 cloudabi64_schedtail(struct thread *td)
123 {
124 	struct trapframe *frame = td->td_frame;
125 
126 	/*
127 	 * Initial register values for processes returning from fork.
128 	 * Make sure that we only set these values when forking, not
129 	 * when creating a new thread.
130 	 */
131 	if ((td->td_pflags & TDP_FORKING) != 0) {
132 		frame->tf_x[0] = CLOUDABI_PROCESS_CHILD;
133 		frame->tf_x[1] = td->td_tid;
134 	}
135 }
136 
137 int
cloudabi64_thread_setregs(struct thread * td,const cloudabi64_threadattr_t * attr,uint64_t tcb)138 cloudabi64_thread_setregs(struct thread *td,
139     const cloudabi64_threadattr_t *attr, uint64_t tcb)
140 {
141 	struct trapframe *frame;
142 	stack_t stack;
143 
144 	/* Perform standard register initialization. */
145 	stack.ss_sp = TO_PTR(attr->stack);
146 	stack.ss_size = attr->stack_len;
147 	cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack);
148 
149 	/*
150 	 * Pass in the thread ID of the new thread and the argument
151 	 * pointer provided by the parent thread in as arguments to the
152 	 * entry point.
153 	 */
154 	frame = td->td_frame;
155 	frame->tf_x[0] = td->td_tid;
156 	frame->tf_x[1] = attr->argument;
157 
158 	/* Set up TLS. */
159 	return (cpu_set_user_tls(td, TO_PTR(tcb)));
160 }
161 
162 static struct sysentvec cloudabi64_elf_sysvec = {
163 	.sv_size		= CLOUDABI64_SYS_MAXSYSCALL,
164 	.sv_table		= cloudabi64_sysent,
165 	.sv_fixup		= cloudabi64_fixup,
166 	.sv_name		= "CloudABI ELF64",
167 	.sv_coredump		= elf64_coredump,
168 	.sv_minuser		= VM_MIN_ADDRESS,
169 	.sv_maxuser		= VM_MAXUSER_ADDRESS,
170 	.sv_stackprot		= VM_PROT_READ | VM_PROT_WRITE,
171 	.sv_copyout_strings	= cloudabi64_copyout_strings,
172 	.sv_setregs		= cloudabi64_proc_setregs,
173 	.sv_flags		= SV_ABI_CLOUDABI | SV_CAPSICUM | SV_LP64,
174 	.sv_set_syscall_retval	= cloudabi64_set_syscall_retval,
175 	.sv_fetch_syscall_args	= cloudabi64_fetch_syscall_args,
176 	.sv_syscallnames	= cloudabi64_syscallnames,
177 	.sv_schedtail		= cloudabi64_schedtail,
178 };
179 
180 INIT_SYSENTVEC(elf_sysvec, &cloudabi64_elf_sysvec);
181 
182 Elf64_Brandinfo cloudabi64_brand = {
183 	.brand		= ELFOSABI_CLOUDABI,
184 	.machine	= EM_AARCH64,
185 	.sysvec		= &cloudabi64_elf_sysvec,
186 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_ONLY_STATIC,
187 };
188