1 /*-
2 * Copyright (c) 2015-2017 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,unsigned long stack)51 cloudabi32_proc_setregs(struct thread *td, struct image_params *imgp,
52 unsigned long stack)
53 {
54 struct trapframe *regs;
55
56 regs = td->td_frame;
57 memset(regs, 0, sizeof(*regs));
58 regs->tf_x[0] =
59 stack + roundup(sizeof(cloudabi32_tcb_t), sizeof(register_t));
60 regs->tf_x[13] = STACKALIGN(stack);
61 regs->tf_elr = imgp->entry_addr;
62 regs->tf_spsr |= PSR_AARCH32;
63 (void)cpu_set_user_tls(td, TO_PTR(stack));
64 }
65
66 static int
cloudabi32_fetch_syscall_args(struct thread * td)67 cloudabi32_fetch_syscall_args(struct thread *td)
68 {
69 struct trapframe *frame;
70 struct syscall_args *sa;
71 int error;
72
73 frame = td->td_frame;
74 sa = &td->td_sa;
75
76 /* Obtain system call number. */
77 sa->code = frame->tf_x[0];
78 if (sa->code >= CLOUDABI32_SYS_MAXSYSCALL)
79 return (ENOSYS);
80 sa->callp = &cloudabi32_sysent[sa->code];
81 sa->narg = sa->callp->sy_narg;
82
83 /*
84 * Fetch system call arguments.
85 *
86 * The vDSO has already made sure that the arguments are
87 * eight-byte aligned. Pointers and size_t parameters are
88 * zero-extended. This makes it possible to copy in the
89 * arguments directly. As long as the call doesn't use 32-bit
90 * data structures, we can just invoke the same system call
91 * implementation used by 64-bit processes.
92 */
93 error = copyin((void *)frame->tf_x[2], sa->args,
94 sa->narg * sizeof(sa->args[0]));
95 if (error != 0)
96 return (error);
97
98 /* Default system call return values. */
99 td->td_retval[0] = 0;
100 td->td_retval[1] = 0;
101 return (0);
102 }
103
104 static void
cloudabi32_set_syscall_retval(struct thread * td,int error)105 cloudabi32_set_syscall_retval(struct thread *td, int error)
106 {
107 struct trapframe *frame = td->td_frame;
108
109 switch (error) {
110 case 0:
111 /*
112 * System call succeeded.
113 *
114 * Simply copy out the 64-bit return values into the
115 * same buffer provided for system call arguments. The
116 * vDSO will copy them to the right spot, truncating
117 * pointers and size_t values to 32 bits.
118 */
119 if (copyout(td->td_retval, (void *)frame->tf_x[2],
120 sizeof(td->td_retval)) == 0) {
121 frame->tf_x[0] = 0;
122 frame->tf_spsr &= ~PSR_C;
123 } else {
124 frame->tf_x[0] = CLOUDABI_EFAULT;
125 frame->tf_spsr |= PSR_C;
126 }
127 break;
128 case ERESTART:
129 /* Restart system call. */
130 frame->tf_elr -= 4;
131 break;
132 case EJUSTRETURN:
133 break;
134 default:
135 /* System call returned an error. */
136 frame->tf_x[0] = cloudabi_convert_errno(error);
137 frame->tf_spsr |= PSR_C;
138 break;
139 }
140 }
141
142 static void
cloudabi32_schedtail(struct thread * td)143 cloudabi32_schedtail(struct thread *td)
144 {
145 struct trapframe *frame = td->td_frame;
146 register_t retval[2];
147
148 /* Return values for processes returning from fork. */
149 if ((td->td_pflags & TDP_FORKING) != 0) {
150 retval[0] = CLOUDABI_PROCESS_CHILD;
151 retval[1] = td->td_tid;
152 copyout(retval, (void *)frame->tf_x[2], sizeof(retval));
153 }
154 frame->tf_spsr |= PSR_AARCH32;
155 }
156
157 int
cloudabi32_thread_setregs(struct thread * td,const cloudabi32_threadattr_t * attr,uint32_t tcb)158 cloudabi32_thread_setregs(struct thread *td,
159 const cloudabi32_threadattr_t *attr, uint32_t tcb)
160 {
161 struct trapframe *frame;
162
163 /*
164 * Pass in the thread ID of the new thread and the argument
165 * pointer provided by the parent thread in as arguments to the
166 * entry point.
167 */
168 frame = td->td_frame;
169 memset(frame, 0, sizeof(*frame));
170 frame->tf_x[0] = td->td_tid;
171 frame->tf_x[1] = attr->argument;
172 frame->tf_x[13] = STACKALIGN(attr->stack + attr->stack_len);
173 frame->tf_elr = attr->entry_point;
174
175 /* Set up TLS. */
176 return (cpu_set_user_tls(td, TO_PTR(tcb)));
177 }
178
179 static struct sysentvec cloudabi32_elf_sysvec = {
180 .sv_size = CLOUDABI32_SYS_MAXSYSCALL,
181 .sv_table = cloudabi32_sysent,
182 .sv_fixup = cloudabi32_fixup,
183 .sv_name = "CloudABI ELF32",
184 .sv_coredump = elf32_coredump,
185 .sv_minuser = VM_MIN_ADDRESS,
186 .sv_maxuser = (uintmax_t)1 << 32,
187 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
188 .sv_copyout_strings = cloudabi32_copyout_strings,
189 .sv_setregs = cloudabi32_proc_setregs,
190 .sv_flags = SV_ABI_CLOUDABI | SV_CAPSICUM | SV_ILP32,
191 .sv_set_syscall_retval = cloudabi32_set_syscall_retval,
192 .sv_fetch_syscall_args = cloudabi32_fetch_syscall_args,
193 .sv_syscallnames = cloudabi32_syscallnames,
194 .sv_schedtail = cloudabi32_schedtail,
195 };
196
197 INIT_SYSENTVEC(elf_sysvec, &cloudabi32_elf_sysvec);
198
199 Elf32_Brandinfo cloudabi32_brand = {
200 .brand = ELFOSABI_CLOUDABI,
201 .machine = EM_ARM,
202 .sysvec = &cloudabi32_elf_sysvec,
203 .flags = BI_BRAND_ONLY_STATIC,
204 };
205