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("$FreeBSD$");
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
47 extern const char *cloudabi32_syscallnames[];
48 extern struct sysent cloudabi32_sysent[];
49
50 static void
cloudabi32_proc_setregs(struct thread * td,struct image_params * imgp,uintptr_t stack)51 cloudabi32_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 r0 point to the auxiliary vector, and set
61 * tpidrurw to the TCB.
62 */
63 regs = td->td_frame;
64 regs->tf_r0 =
65 stack + roundup(sizeof(cloudabi32_tcb_t), sizeof(register_t));
66 (void)cpu_set_user_tls(td, TO_PTR(stack));
67 }
68
69 static int
cloudabi32_fetch_syscall_args(struct thread * td)70 cloudabi32_fetch_syscall_args(struct thread *td)
71 {
72 struct trapframe *frame;
73 struct syscall_args *sa;
74 int error;
75
76 frame = td->td_frame;
77 sa = &td->td_sa;
78
79 /* Obtain system call number. */
80 sa->code = frame->tf_r12;
81 if (sa->code >= CLOUDABI32_SYS_MAXSYSCALL)
82 return (ENOSYS);
83 sa->callp = &cloudabi32_sysent[sa->code];
84
85 /* Fetch system call arguments from registers and the stack. */
86 sa->args[0] = frame->tf_r0;
87 sa->args[1] = frame->tf_r1;
88 sa->args[2] = frame->tf_r2;
89 sa->args[3] = frame->tf_r3;
90 if (sa->callp->sy_narg > 4) {
91 error = copyin((void *)td->td_frame->tf_usr_sp, &sa->args[4],
92 (sa->callp->sy_narg - 4) * sizeof(register_t));
93 if (error != 0)
94 return (error);
95 }
96
97 /* Default system call return values. */
98 td->td_retval[0] = 0;
99 td->td_retval[1] = frame->tf_r1;
100 return (0);
101 }
102
103 static void
cloudabi32_set_syscall_retval(struct thread * td,int error)104 cloudabi32_set_syscall_retval(struct thread *td, int error)
105 {
106 struct trapframe *frame = td->td_frame;
107
108 switch (error) {
109 case 0:
110 /* System call succeeded. */
111 frame->tf_r0 = td->td_retval[0];
112 frame->tf_r1 = td->td_retval[1];
113 frame->tf_spsr &= ~PSR_C;
114 break;
115 case ERESTART:
116 /* Restart system call. */
117 frame->tf_pc -= 4;
118 break;
119 case EJUSTRETURN:
120 break;
121 default:
122 /* System call returned an error. */
123 frame->tf_r0 = cloudabi_convert_errno(error);
124 frame->tf_spsr |= PSR_C;
125 break;
126 }
127 }
128
129 static void
cloudabi32_schedtail(struct thread * td)130 cloudabi32_schedtail(struct thread *td)
131 {
132 struct trapframe *frame = td->td_frame;
133
134 /*
135 * Initial register values for processes returning from fork.
136 * Make sure that we only set these values when forking, not
137 * when creating a new thread.
138 */
139 if ((td->td_pflags & TDP_FORKING) != 0) {
140 frame->tf_r0 = CLOUDABI_PROCESS_CHILD;
141 frame->tf_r1 = td->td_tid;
142 }
143 }
144
145 int
cloudabi32_thread_setregs(struct thread * td,const cloudabi32_threadattr_t * attr,uint32_t tcb)146 cloudabi32_thread_setregs(struct thread *td,
147 const cloudabi32_threadattr_t *attr, uint32_t tcb)
148 {
149 struct trapframe *frame;
150 stack_t stack;
151
152 /* Perform standard register initialization. */
153 stack.ss_sp = TO_PTR(attr->stack);
154 stack.ss_size = attr->stack_len;
155 cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack);
156
157 /*
158 * Pass in the thread ID of the new thread and the argument
159 * pointer provided by the parent thread in as arguments to the
160 * entry point.
161 */
162 frame = td->td_frame;
163 frame->tf_r0 = td->td_tid;
164 frame->tf_r1 = attr->argument;
165
166 /* Set up TLS. */
167 return (cpu_set_user_tls(td, TO_PTR(tcb)));
168 }
169
170 static struct sysentvec cloudabi32_elf_sysvec = {
171 .sv_size = CLOUDABI32_SYS_MAXSYSCALL,
172 .sv_table = cloudabi32_sysent,
173 .sv_fixup = cloudabi32_fixup,
174 .sv_name = "CloudABI ELF32",
175 .sv_coredump = elf32_coredump,
176 .sv_minuser = VM_MIN_ADDRESS,
177 .sv_maxuser = VM_MAXUSER_ADDRESS,
178 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
179 .sv_copyout_strings = cloudabi32_copyout_strings,
180 .sv_setregs = cloudabi32_proc_setregs,
181 .sv_flags = SV_ABI_CLOUDABI | SV_CAPSICUM | SV_ILP32,
182 .sv_set_syscall_retval = cloudabi32_set_syscall_retval,
183 .sv_fetch_syscall_args = cloudabi32_fetch_syscall_args,
184 .sv_syscallnames = cloudabi32_syscallnames,
185 .sv_schedtail = cloudabi32_schedtail,
186 };
187
188 INIT_SYSENTVEC(elf_sysvec, &cloudabi32_elf_sysvec);
189
190 Elf32_Brandinfo cloudabi32_brand = {
191 .brand = ELFOSABI_CLOUDABI,
192 .machine = EM_ARM,
193 .sysvec = &cloudabi32_elf_sysvec,
194 .flags = BI_BRAND_ONLY_STATIC,
195 };
196