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