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 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 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 66static int 67cloudabi32_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 104static void 105cloudabi32_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 142static void 143cloudabi32_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 157int 158cloudabi32_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 179static 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 197INIT_SYSENTVEC(elf_sysvec, &cloudabi32_elf_sysvec); 198 199Elf32_Brandinfo cloudabi32_brand = { 200 .brand = ELFOSABI_CLOUDABI, 201 .machine = EM_ARM, 202 .sysvec = &cloudabi32_elf_sysvec, 203 .flags = BI_BRAND_ONLY_STATIC, 204}; 205