cloudabi64_sysvec.c revision 307144
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: stable/11/sys/amd64/cloudabi64/cloudabi64_sysvec.c 307144 2016-10-12 12:17:41Z ed $"); 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 47extern const char *cloudabi64_syscallnames[]; 48extern struct sysent cloudabi64_sysent[]; 49 50static int 51cloudabi64_fixup_tcb(register_t **stack_base, struct image_params *imgp) 52{ 53 int error; 54 register_t tcbptr; 55 56 /* Place auxiliary vector and TCB on the stack. */ 57 error = cloudabi64_fixup(stack_base, imgp); 58 if (error != 0) 59 return (error); 60 61 /* 62 * On x86-64, the TCB is referred to by %fs:0. Take some space 63 * from the top of the stack to store a single element array, 64 * containing a pointer to the TCB. %fs base will point to this. 65 */ 66 tcbptr = (register_t)*stack_base; 67 return (copyout(&tcbptr, --*stack_base, sizeof(tcbptr))); 68} 69 70static void 71cloudabi64_proc_setregs(struct thread *td, struct image_params *imgp, 72 unsigned long stack) 73{ 74 struct trapframe *regs; 75 76 exec_setregs(td, imgp, stack); 77 78 /* 79 * The stack now contains a pointer to the TCB, the TCB itself, 80 * and the auxiliary vector. Let %rdx point to the auxiliary 81 * vector, and set %fs base to the address of the TCB. 82 */ 83 regs = td->td_frame; 84 regs->tf_rdi = stack + sizeof(register_t) + 85 roundup(sizeof(cloudabi64_tcb_t), sizeof(register_t)); 86 (void)cpu_set_user_tls(td, (void *)stack); 87} 88 89static int 90cloudabi64_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 91{ 92 struct trapframe *frame = td->td_frame; 93 94 /* Obtain system call number. */ 95 sa->code = frame->tf_rax; 96 if (sa->code >= CLOUDABI64_SYS_MAXSYSCALL) 97 return (ENOSYS); 98 sa->callp = &cloudabi64_sysent[sa->code]; 99 sa->narg = sa->callp->sy_narg; 100 101 /* Fetch system call arguments. */ 102 sa->args[0] = frame->tf_rdi; 103 sa->args[1] = frame->tf_rsi; 104 sa->args[2] = frame->tf_rdx; 105 sa->args[3] = frame->tf_rcx; /* Actually %r10. */ 106 sa->args[4] = frame->tf_r8; 107 sa->args[5] = frame->tf_r9; 108 109 /* Default system call return values. */ 110 td->td_retval[0] = 0; 111 td->td_retval[1] = frame->tf_rdx; 112 return (0); 113} 114 115static void 116cloudabi64_set_syscall_retval(struct thread *td, int error) 117{ 118 struct trapframe *frame = td->td_frame; 119 120 switch (error) { 121 case 0: 122 /* System call succeeded. */ 123 frame->tf_rax = td->td_retval[0]; 124 frame->tf_rdx = td->td_retval[1]; 125 frame->tf_rflags &= ~PSL_C; 126 break; 127 case ERESTART: 128 /* Restart system call. */ 129 frame->tf_rip -= frame->tf_err; 130 frame->tf_r10 = frame->tf_rcx; 131 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 132 break; 133 case EJUSTRETURN: 134 break; 135 default: 136 /* System call returned an error. */ 137 frame->tf_rax = cloudabi_convert_errno(error); 138 frame->tf_rflags |= PSL_C; 139 break; 140 } 141} 142 143static void 144cloudabi64_schedtail(struct thread *td) 145{ 146 struct trapframe *frame = td->td_frame; 147 148 /* Initial register values for processes returning from fork. */ 149 frame->tf_rax = CLOUDABI_PROCESS_CHILD; 150 frame->tf_rdx = td->td_tid; 151} 152 153int 154cloudabi64_thread_setregs(struct thread *td, 155 const cloudabi64_threadattr_t *attr, uint64_t tcb) 156{ 157 struct trapframe *frame; 158 stack_t stack; 159 uint64_t tcbptr; 160 int error; 161 162 /* 163 * On x86-64, the TCB is referred to by %fs:0. Take some space 164 * from the top of the stack to store a single element array, 165 * containing a pointer to the TCB. %fs base will point to this. 166 */ 167 tcbptr = rounddown(attr->stack + attr->stack_size - sizeof(tcbptr), 168 _Alignof(tcbptr)); 169 error = copyout(&tcb, (void *)tcbptr, sizeof(tcb)); 170 if (error != 0) 171 return (error); 172 173 /* Perform standard register initialization. */ 174 stack.ss_sp = TO_PTR(attr->stack); 175 stack.ss_size = tcbptr - attr->stack; 176 cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack); 177 178 /* 179 * Pass in the thread ID of the new thread and the argument 180 * pointer provided by the parent thread in as arguments to the 181 * entry point. 182 */ 183 frame = td->td_frame; 184 frame->tf_rdi = td->td_tid; 185 frame->tf_rsi = attr->argument; 186 187 return (cpu_set_user_tls(td, (void *)tcbptr)); 188} 189 190static struct sysentvec cloudabi64_elf_sysvec = { 191 .sv_size = CLOUDABI64_SYS_MAXSYSCALL, 192 .sv_table = cloudabi64_sysent, 193 .sv_fixup = cloudabi64_fixup_tcb, 194 .sv_name = "CloudABI ELF64", 195 .sv_coredump = elf64_coredump, 196 .sv_pagesize = PAGE_SIZE, 197 .sv_minuser = VM_MIN_ADDRESS, 198 .sv_maxuser = VM_MAXUSER_ADDRESS, 199 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE, 200 .sv_copyout_strings = cloudabi64_copyout_strings, 201 .sv_setregs = cloudabi64_proc_setregs, 202 .sv_flags = SV_ABI_CLOUDABI | SV_CAPSICUM | SV_LP64, 203 .sv_set_syscall_retval = cloudabi64_set_syscall_retval, 204 .sv_fetch_syscall_args = cloudabi64_fetch_syscall_args, 205 .sv_syscallnames = cloudabi64_syscallnames, 206 .sv_schedtail = cloudabi64_schedtail, 207}; 208 209INIT_SYSENTVEC(elf_sysvec, &cloudabi64_elf_sysvec); 210 211Elf64_Brandinfo cloudabi64_brand = { 212 .brand = ELFOSABI_CLOUDABI, 213 .machine = EM_X86_64, 214 .sysvec = &cloudabi64_elf_sysvec, 215 .flags = BI_CAN_EXEC_DYN, 216 .compat_3_brand = "CloudABI", 217}; 218